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close this bookEnergy as an Instrument for Socio-economic Development (UNDP, 1995, 114 p.)
View the document5. From Energy Efficiency to Social Utility: Lessons from Cookstove Design, Dissemination, and Use
View the document6. PV, Wind, and Other Dispersed Energy Sources
View the document7. Renewable Energy Benefits Rural Women in China
View the document8. Community Biogas Plants Supply Rural Energy and Water: The Pura Village Case Study

5. From Energy Efficiency to Social Utility: Lessons from Cookstove Design, Dissemination, and Use


With roughly half the world's population cooking daily with the traditional biomass fuels of dung, crop residues, wood, and charcoal, efforts to disseminate improved, more efficient cookstoves are an ideal way to address a wide range of socio-economic and environmental goals. These goals include conserving energy, reducing the time spent collecting wood, expanding economic opportunities for both rural and urban families, empowering women, reducing harmful household smoke exposure, reducing forest clearing and ecological alteration, and mitigating global atmospheric pollution. Widespread dissemination and use of improved woodstoves has the potential to impact each of these objectives, and thus, has been a focal point of household development and quality of life efforts for several decades.

The statistics on the role and impact of biomass use on the energy-health-environment cycle are striking. Half the more than 3,000 million tons of wood harvested annually worldwide is used as fuel. Wood and other biomass fuels comprise 40 to 60 per cent of all energy resources, both industrial and domestic, in many Asian, Latin American, and African countries. In sub-Saharan Africa, on average, domestic cooking accounts for over 60 per cent of total national energy use; in some countries, it exceeds 80 per cent.2 Some poor families spend 20 per cent or more of disposable income to purchase wood and charcoal fuels, or devote 25 per cent or more of total household labour to wood collecting.3 Biomass fuels are generally utilized at a low thermodynamic efficiency. Reliance on them thus entails a high opportunity cost for poor households, and has serious health and environmental costs as well.

Biomass is used not only for domestic purposes. Other uses include construction materials, industrial energy, and simply as cleared land for agriculture. However, the need for cooking fuel is constant; in some developing countries, it exceeds one ton per capita per year.4 The environmental impact of all forms of wood use - industrial, agricultural, and domestic - varies widely, ranging from areas with ecologically sustainable harvest levels5 to regions where population density and woodfuel demand alter the type of forest cover and biodiversity. In the most extreme cases, dramatic deforestation and erosion result.6

Biomass cooking fuels are often combusted inefficiently. Open "three stone" fires and some traditional stove designs generate large quantities of smoke and particulate matter, while directing only a small fraction of the resulting heat to the cooking pots. Sometimes, as little as 5 to 15 per cent of the total energy content of the fuel is utilized to heat the food.7

High levels of indoor air pollution create serious health problems. Air quality studies in developing countries have shown that woodsmoke exposure can often be twenty times or more the exposure limits recommended by the World Health Organization. The pollution level in homes and cooking huts can exceed those in industrial cities. High indoor air pollution, in turn, is linked to acute respiratory infection (ARI), particularly pneumonia, and other ailments. Those most continuously exposed to indoor air pollution are women - who perform over 90 per cent of domestic chores, including cooking - and children. In fact, ARI is the leading health hazard to children in developing countries, and results in an estimated 4.3 million deaths per year among the overall population.8 Among all endemic diseases, including diarrhea, ARI is the most pervasive cause of chronic illness.

Researchers confronted with a continuing dependence on biomass fuels, traditional woodfuel management schemes, and traditional cooking stoves have concluded that the introduction of improved cookstoves could have a dramatic development impact. Specific designs vary widely, but most cookstoves are made to consume less fuel per amount of useful energy delivered and/or to emit less pollution, which benefits the health of the user as well as the environment. Widespread dissemination and adoption of technically and culturally appropriate stoves could reduce the need for fuelwood harvesting (and thus, human impact on forest systems), while reducing human exposure to indoor air pollution.

Reducing the labour and capital required to collect or purchase cooking fuels could also provide new resources and expand economic opportunities to women throughout the developing world.9 Indeed, the fact that the management of biomass fuels and cooking techniques is so interrelated with energy, food, health, and the economy in developing countries has led one researcher to coin the phrase "the hearth as central system."10

Cookstoves and the Technology-for-Development Paradigm

Recent surveys have identified several hundred individual cook-stove research and dissemination projects. The scale of cookstoves programmes ranges from entirely local (often consisting of nongovernmental advocacy and implementation activities) to national initiatives reaching over 100 million homes,11 to regional programmes sponsored by multinational development agencies.12 These programmes have used a wide range of stove designs, from massive sand and clay models to a variety of portable metal and ceramic stoves. They have tested and utilized various technology transfer paradigms; these paradigms have ranged from promoting commercial cookstove mass-production and sales to training the eventual users of cookstoves, primarily women, to adapt and construct stoves for their home use.

The quality and efficiency of stoves has varied greatly, as has the success of individual projects in reaching the intended audience or developing a self-sustaining market or cook-stove industry.13 Because cookstove projects have such a long, diverse history, they can serve as a crucial test of the kind of small-scale, household-oriented paradigm of development long promoted by appropriate technology advocates.14 They can also serve as a model for design and dissemination efforts of such other renewable energy technologies as biogas digesters, solar ovens and food dryers, household photovoltaic systems, wind-pumps, and micro-hydro stations.

The evolving tools and continuing pitfalls of technology-transfer and implementation projects can be critically examined by analyzing the changing goals and implementation strategies of cookstove projects. This paper summarizes the changes in: a) the technology of improved cookstoves, and b) the resulting economic, health, environmental conservation, and social empowerment opportunities. Particularly notable are the following: the expanded communication and cooperation between project implementors and end-user groups, the growth of market-based technology transfer mechanisms (even in peri-urban settings, where markets did not seem initially to exist), the analysis of rural vs. urban market potential, and the design of multi-objective efforts that integrate disparate actors in the development process. The evolving understanding and interaction of these factors in the cookstove design, development, dissemination, and adoption chain provide the clearest lessons for the role of household energy in managing social change, empowerment, and development generally.

Improved Stoves: Design Engineering and Energy Efficiency

Improved cookstove designs fall into two broad categories: fixed location and portable models. The immobile stoves are commonly made from a combination of metal, clay, ceramic, or cement. These designs generally achieve energy conservation through insulation and are often "complete" stoves, with an enclosed burning chamber and multiple openings for pots (burners). Massive stove designs have been extensively tested, refined, and introduced and re-introduced in Latin America and Asia.15 Portable stoves are generally constructed of metal with clay or ceramic liners, or as formed clay "burners" that support one pot over an enclosed burning box. As is not surprising, there are a great many designs, all of which are geared to meet the same general objective:

· Maximize combustion of the fuel by keeping the temperature high and ensuring the presence of sufficient oxygen;

· Maximize radiative heat transfer from the fire to the pot(s) by keeping the pot as close to the flame as possible;

· Maximize convection from the tire to the pot(s) with a stove design that passes as much of the hot gases over the pot(s) as possible; reduce drafts;

· Maximize conduction to the food pot(s) by using an insulating material for the stove so that the heat is retained and concentrated near the pot(s);

· Maximize user satisfaction by making the stoves convenient to use (with local fuels, cooking pots, and utensils) and able to easily prepare local dishes well.

In summary, only a stove with what might be called robust efficiency will consistently save fuel under conditions of actual use. Stoves must be easy to use and fuel efficient under a variety of conditions: when it is boiling, simmering, baking, or frying food; when it is using only one opening of a large, three-pot stove; and when it is dirty or worn. Stoves evaluated in idealized laboratory conditions, very different from the environmental and practical constraints of real-world kitchens and cooking huts, have too often failed to meet this requirement of robust efficiency. Cookstoves are workhorses, not racehorses, and must be designed accordingly.

Early cookstove projects were heralded as the solutions to a tremendous array of social, economic, and environmental ills - from deforestation to the oppression of women. Although improved cookstove efficiency and household energy security can lead to improvements in all of these areas, evaluations of early projects were generally disappointing.16 Many of the early projects failed for both technical and social reasons. As one analyst has stated: "Early improved cookstoves were often designed by development workers with a great deal of zeal and enthusiasm, but little technical background. Under the banner of 'appropriate technology,' new designs were quickly labeled 'improved stoves' and construction manuals prepared, without prior serious scientific research."17

Advocates and researchers involved in early stove projects fell into the trap of equating "appropriate" technology with "simple" technology. The first four design factors in the list above, essentially thermodynamic criteria, have proved difficult to achieve.18

Many early programmes expected to see efficiency gains of 75 per cent or more.19 However, these expectations were based on tremendously idealized cooking conditions never realized in the field. Many new stoves were expensive and difficult to use, and degraded rapidly with use. The wood savings realized in actual home settings tend to follow a distribution, as shown below:20


wood savings (%)


40 +








-10 to -25


no longer in use

In aggregate, these data correspond to fuel savings of about 20 per cent per stove, an impressive and important reduction, although considerably less than the early claims of some wood-stove projects.21 Construction of massive, in-place design stoves in each house (i.e., built one at a time without standardization or economies of scale) often resulted in uneven quality and efficiency. For all these reasons, many new stove designs and dissemination programmes failed the test of "robust efficiency."

At the same time, claims that traditional stoves were only 5 to 10 per cent efficient neglected the many other benefits they provided: lighting, space heating, ease of use, and versatility. In fact, under conditions of shielded, carefully tended use, three-stone fires can reach efficiencies of 20 per cent.22

In many early projects, the end-users, generally women, were not involved in initial discussions, feedback, or training programmes; these were inappropriately targeted to men or to extension workers who rarely cooked food themselves.23 At the same time, many of the basic lessons of commercial enterprises were lost, partly because stove projects were categorized as development aid and assistance. Little market research was initially undertaken to determine the most pressing concerns of the women who would use the stoves, the local perceptions of fuel scarcity or abundance, or even the suggestions of local communities about cookstove design or the kind of programmes that could make them available. The combination of the oversell of improved cookstoves and the under appreciation of the reliability and versatility of traditional methods meant that the fuel savings in some early efforts amounted to little or nothing.

The disappointing results of the early efforts led to re-evaluation of the engineering and design of stoves, to greater end-user participation, and to far more rigorous and realistic measures of actual stove performance. This more pragmatic approach then began to yield broadly useful efficiency and cost comparison data for second-generation stove projects.

A series of practical measurements of actual stove efficiencies conducted in West Africa is particularly instructive. A useful measure of stove performance is the percentage of heat utilized (PHU), a ratio of the energy utilized/energy expended. It is obtained by boiling and then continuing to cook a volume of water while measuring the total fuel combusted, the volume of water boiled, and water boiled off - all in a series of comparable field settings. Table 5.1 shows the PHU for a variety of stoves commonly used in West Africa.

For the stoves listed in Table 5.1, prices range from essentially no cost for a three-stone fire (except for the cost of the pots) to more than $20. At the prevailing cost of wood, these prices (omitting the three-stone fire) correspond to amortized payback times ranging from one month to over a year.24 Fuel savings compared to traditional stoves are as much as 60 per cent for the expensive CATRU-A stove, and as little as 5 per cent for some simple and inexpensive designs.

Stove dissemination programmes should not be undertaken lightly. They involve significant financial investment by both users and donors, and require a long-term commitment of research, training, and support services to be successful. However, one of the most promising aspects of such programmes is the growing realization that reducing woodsmoke exposure has a wide range of important health benefits. The impact of stove programmes on both pressing energy and health problems can be used effectively to broaden the base of support in providing the needed long-term resource commitment necessary to generate successful, self-supporting programmes and industries.

Table 5.1 - Efficiency Comparison of Several West African Improved and Traditional Stoves




% increase in PHU over:

% decrease in wood use over:





Three Stone

Pot supported by three stones over open fire






Metal Stove

Simple 1-pot metal stove







Sand insulation placed around the simple metal stove







Clay shell stove around a single pot







3-pot partially insulated stove, without chimney






GS Chula

Insulated 2-pot lorena-type stove with chimney







Brick and cement lorena-type stove







Lorena-type, aluminum top plate and matched pots







CATRU-B with improved chimney






Note: The PHU (or percentage of heat utilized) is based on a combination of the initial boiling and sustained cooking (simmering) phase - thus providing a proxy for realistic cooking conditions. The PHU values reported here are averaged over five or more measurements per stove. Each stove is compared here to both a traditional three-stone fire and a metal stove. The Three-Stone, Metal, SIM, and Sota stoves all accommodate one pot only; the AIDR stove has openings for three pots; and the remaining four stoves all have two openings. Wood savings over traditional fires range from minimal (6 per cent) to dramatic (61 per cent).

Source: Data derived from TS. Wood, Laboratory and Field Testing of Improved Stoves in Upper Volta (Mt. Rainier, MD: VITA, 1981); S. Connors, "Wood-Conserving Cookstoves: A Short Primer for the Design and Implementation of Woodstoves and Woodstove Projects," Peace Corps/Benin (1987), mimeo; and S. Baldwin, H. Geller, G. Dutt, and N.H. Ravindranath, " Improved Woodburning Cookstoves: Signs of Success," Ambio 14(1985).

The Cooking Environment, Smoke Exposure, and Health Risks

The connection between wood use, cooking, and the epidemiology of respiratory and other illnesses is a topic of active current research. However, a consistent pattern linking energy, environment, and health has already become alarmingly clear. Biomass fuels provide 90 to 95 per cent of domestic energy in sub-Saharan Africa, most of it for cooking." Combustion of these fuels in confined, often unventilated, indoor areas and at low thermodynamic efficiency leads to high concentrations of smoke and pollution. To evaluate how effective improved cookstoves and household energy management are in mitigating these harmful health conditions, it is necessary to consider the entire food preparation cycle, including energy and environmental management, and household risk and economic decision-making.

The food preparation process is one of the most important health and development issues facing poor countries. Biomass cooking on traditional stoves is a major source of concentrated air pollutants, including respirable particulate matter, carbon monoxide, nitrogen oxides, benzene, formaldehyde, benzo(a)pyrene, and aromatics.26 Particulates seem to be the primary culprit in smoke-related illnesses.27 In some places, the pollutant exposure levels associated with indoor biomass burning in developing countries is many times greater than accepted health standards. U.S. standards, for example, call for maximum particulate concentrations of 250 micrograms per cubic metre (not to be exceeded more than once a year). However, in developing countries, people are routinely exposed to indoor particulate concentrations many times that high (see Table 5.2). These levels rival or even exceed the pollution levels found in the most polluted industrial cities.28 Women and children are particularly affected, since cooking smoke is confined to indoor settings, where they are exposed for extended periods of time.

The living conditions that expose people to high levels of indoor air pollution have been well documented in Africa. The majority of sub-Saharan Africans live in rural areas; Kenya, for example, is only about 20 per cent urban. Family homes generally consist of multi-use buildings, where the same room or few rooms are used for cooking, sleeping, and working. In many cases, the total indoor volume is less than 40 cubic metres; in some (such as the Maasai homes in Kenya), indoor air volumes may be half that. Rural homes often have minimal ventilation; when people cook, they may close the door or, when they exist, plug the windows with cloth.29 Ventilation is further reduced during rainy seasons, cold spells, and at higher elevations.30

Under these circumstances, pollutant concentrations resulting from cooking can easily build to unhealthy levels and remain that way over the course of a day. Compounding the problem is the type of cooking practiced in much of Africa. In many countries, the staple foods are grain and legume combinations that require long cooking times. In Kenya, for example, preparation of the staple maize and bean dish (ugali, a hardened corn meal, and irio, a simmered mixture of several beans) requires several hours of softening and slow cooking that can consume wood at the relatively high rates of 1.5 -3.0 kilograms per hour.

High pollution levels are not limited to rural areas. The close quarters of urban slums, and even the minimal spaces sometimes allocated to household servants in more affluent households, and the heavy use of traditional cooking fuels, notably charcoal, all contribute to urban pollution. Poverty and overcrowding can increase the ambient pollution concentration over entire neighbourhoods, where woodsmoke mixes with photochemical smog.

Table 5.2 - Indoor Particulate Concentrations In Developing Countries, Summary of Selected Studies



Number of measurements

micrograms per cubic metre


Kenya (1972)

Night: highlands



Kenya (1972)

Night: lowlands



Kenya (1987)

24 hour exposure



Kenya (1993)

Unvented hut: cooking



Nepal (1988)

24 hour exposure



Gambia (1988)

24 hour exposure



Zimbabwe (1990)

While cooking




India (1983)



India (1988)



India (1988)



India (1988)



Nepal (1986)



Nepal (1988)

Traditional stoves



Nepal (1988)

Improved stoves



US 24-hour standard
(not to be exceeded more than once/year)


US Annual Urban Levels


Note: These measurements of particulate concentrations, in micrograms per cubic metre, were obtained under a range of conditions - during cooking, as a daily average, etc. They are not directly comparable, but give a feel for the range of concentrations. The measured concentrations are consistently far above the U.S. one-time exposure standard and the annual average. Measurements are for particles having a diametre greater than 10 microns.

Source: Data from P. Young and K. Wafula, "Smoked Maasai," ITDG/KENGO (London, 1993), mimeo; K.R. Smith et al., "Greenhouse Gases from Biomass and Fossil Fuel Stoves in Developing Countries: A Manila Pilot Study," Chemosphere 26 (1992), pp. 479-506; and K.R. Smith, "The Health Impact of Cookstove Smoke in Africa," in African Development Perspectives Yearbook 3 (Muenster: Lit Verlag, 1994).

Health Effects of Biomass Burning

Numerous studies demonstrate a consistent positive correlation between exposure to smoke from indoor biomass burning and acute respiratory infection and chronic lung disease (Table 5.3). Ongoing research is attempting to determine the precise dose response relationship;31 in the meantime, however, long-term exposure to smoke from biomass combustion has been observed to elevate the risk of a child developing ARI by 100 to 400 per cent.32 Less well documented studies have linked woodsmoke to an increased incidence of eye infections, low birth weight, and cancer. Health clinics and mobile physician programmes in developing countries routinely treat both children and adults for serious bums resulting from direct contact with cooking fires.

Table 5.3 - Summary of Studies of Household Biomass Combustion and Acute Respiratory Infection (ARI) Among Infants

Study (year)

Case/Control (ARI determination)

Exposure & measurements

AM relative risk (95% confidence interval)

1. Natal, South Africa (1980)


Cookfire smoke
X-Ray and ARI cases


2. Basse, The Gambia (1989)


Child carried by mother
Reported breathlessness


3. Maragua, Kenya (1986,1990)


Woodsmoke exposure
Particulate monitoring


4. Marondera, Zimbabwe (1990)


Open fire cooking
ARI hospitalizations


5. Basse, The Gambia (1991)


Child carried by mother
Reported breathlessness

Girls: 6.0
Boys: N/S

Notes: The studies looked at ARI among infants, 0 to 59 months of age. The relative risk (incidence ratio to that in the control group) is shown with the uncertainty range at the 95 per cent confidence interval (CI). N/S= not statistically significant.

Source: K.R. Smith, "The Health Impact of Cookstove Smoke in Africa," in African Development Perspectives Yearbook 3 (Muenster: Lit Verlag, 1994).

The extent of the woodsmoke health crisis in developing countries is beginning to gain international attention. The World Health Organization estimates that 1.5 billion people live under conditions of unhealthy air. Four to five million childhood deaths are attributed to acute respiratory infection every year. Regional health reports provide another measure of the pervasive nature of the health hazard. For example, Laikipia District in Kenya is a relatively prosperous mixed agricultural and farming region. However, even here, annual morbidity data from district hospitals and clinics show that respiratory infections head up the list of most commonly reported diseases, accounting for a third of all afflictions reported and diagnosed. Eye infections, also linked to woodsmoke exposure, are on the list of top ten diseases as well.

Although more research is needed to determine the precise relationship between woodsmoke dose and morbidity response, it has become clear that improved, low-emission cookstoves are as important to improving health conditions as to conserving fuel. Additional dose-response information is critically needed to develop guidelines for predicting at-risk groups and designing preventive health care programmes; it could also be used to evaluate the cost/benefit tradeoffs of various types of education and cookstove design and dissemination projects. For example, the preliminary exposure and morbidity data in Tables 5.1-5.4 provide evidence of a hazard, but are insufficient to delineate what degree of smoke reduction will generate significant improvements in human health; this is the classic "how clean is clean enough" problem in environmental science and engineering. Although they have drawbacks, cost/benefit evaluations are particularly useful in making renewable energy and energy efficiency projects mainstream rather than additional activities. All too often, renewables are still considered an unnecessary luxury. However, when the results of renewable energy dissemination efforts can be measured in terms of cost and benefit, resistance becomes significantly less.33

Cookstove Technology and Indoor Air Pollution

As the health risks associated with biomass cooking become increasingly clear, the case for continued and expanded improved stove projects is strengthened. Improved cookstove and outreach, education, demonstration, and construction efforts can contribute to reducing harmful woodsmoke exposure in a number of ways: a) by improving venting of combustion gases through use of a flue or chimney, b) by improving combustion efficiency through better stove designs, and c) by encouraging use of cleaner burning fuels and more advanced stove designs - a process called moving up the "energy ladder."

By reducing the time needed to collect (or to purchase) cooking fuels and combining health gains with improvements in household fuel, cookstove programmes can meet economic efficiency, environmental conservation, and quality of life objectives. Transition to more advanced stove designs and cleaner fuels can significantly reduce indoor air pollution (see Table 5.4).

Table 5.4 - Concentration of Carbon Monoxide (CO) From Indoor Biofuel Combustion, Various Fuel and Stove Combinations, Kenya

Fuel and Stove Combination

No. of Measurements

[CO] (parts per million by volume)

Dung/Traditional Stove



Wood/Traditional Stove



Charcoal/Traditional Stove



Charcoal/Improved Stove



Kerosene Fuel and Stove



WHO 1-hour exposure standard


Notes: The carbon monoxide measurements art for a typical range of concentrations measured one metre above the stove during food preparation. They are instantaneous values, not time averages, collected in 1992 and 1993 from homes in southern and eastern Kenya; the homes are culturally relatively homogenous, but economically stratified. The energy ladder "increases" from the top to the bottom of this list of stove/fuel combinations.

The "energy ladder" concept is fundamental to efforts to understand household energy decision-making.34 It is the household or micro-economic corollary to what happens at the macro-economic level, as countries industrialize and move from traditional biomass to commercial fossil-fuel-based economies. Under this hypothesis, as households become more affluent, they move from simple stoves and inexpensive fuels to more sophisticated, convenient, and costly fuels and stoves. The ladder climbs from dung or crop residues combusted in three-stone fires, to wood or charcoal use in metal or improved stoves, to kerosene wick or pressure systems, and finally to propane, liquid petroleum, and electric appliances.

The health and energy impact of climbing up this ladder can be dramatic. Simple biomass stoves may use six or seven times as much fuel as a modern stove, and release 50 times more pollutants than a gas stove used to prepare the same quantity of food.35 The poorest segments of society, thus, not only are exposed to higher levels of pollution, but must also spend a greater share of household income and resources to cook the same meal.

Some aspects of moving from traditional to improved stoves - or from dung and wood to charcoal, kerosene, and other fuels - may actually introduce new risks. For example, although an improved, charcoal-burning stove may emit less total pollution than a traditional stove, carbon monoxide may still be produced at higher levels than those recommended by the World Health Organization. Since carbon monoxide is odourless and colourless, there may be acute risk of poisoning without the warning signs of coughing and tearing that are associated with hydrocarbons and particulates in woodsmoke.

In many ways, the energy ladder is too simplistic a view of energy decision-making. In Africa, although families acquire new cooking technologies as resources permit, they rarely abandon the more traditional metal stoves, or even three-stone fires. Instead of moving up an energy ladder or emphasizing energy efficiency, they pursue a more eclectic pattern of acquiring energy security. Improved cookstove programmes designed to augment positive social change must work with, rather than against, this process. The focus of programmes to provide small-scale domestic and community-based energy resources must be to give households a diverse set of energy services. End-users of energy services must have the opportunity to evaluate, and choose among a range of alternatives that fit their specific needs, rather than be presented with a single technology in a "take it or leave it" development project.

Improved Cookstove Programmes in East Africa

Except for the large cookstove programmes of India and China, the varied efforts to introduce improved stoves to East Africa have been the most extensive.36 The most widely used model in East Africa is the Kenya Ceramic Jiko (KCJ), of which more than 700,000 are in use today. Proponents of the KCJ report an adoption rate of 56 per cent among urban households, where most efforts have been focused, and an impressive 16 per cent nationwide.37 The problems encountered and the lessons learned in East Africa are now being incorporated into cookstove programmes worldwide.

Improved cookstove design and dissemination programmes in East Africa date from the 1970s. Financial and technical support was provided by a variety of bilateral and multilateral development agencies and non-governmental organizations, with financial contributions ranging from several thousand to over four million dollars. Local non-governmental organizations and community/activist groups, as well as government agencies, were involved in research, development, support, and dissemination.38

Both the strengths and the problems associated with cookstove programmes can be traced to the diversity of actors, methods, and resources brought to bear on the complex interplay among stove performance and cost, user needs and resources, how the method was introduced, and the local stove/fuel economy

Some early efforts in Kenya generally failed the "robust efficiency" criteria outlined earlier; they were poorly designed, had overly optimistic expectations of the amount of wood and charcoal savings, and the stoves were inconvenient to use.39

In addition, they focused on a difficult market - on the rural poor, who do not purchase fuel, rather than on the more affluent urban population, who already regularly purchased both fuel and stoves. After learning from these mistakes, the Kenya Ceramic Jiko Programme is now considered a model programme with the most popular stove. The KCJ is constructed by several hundred distinct commercial producers; over 13,000 KCJ stoves are sold each month in stores and markets throughout urban areas. Critical to Kenya's success are the efforts of many agencies - bilateral, multilateral, non-governmental, and governmental - to promote and popularize the stove.

Today, the various cookstove efforts in Kenya include the KCJ as well as other designs, and are targeted at more than simply the urban population. They include the Kuni Mbili (two-stick) stove, which has a larger burning box than the KCJ to accommodate the primary rural fuel of wood, and the Maendeleo or Upesi (quick) stove, which consists of an inexpensive manufactured liner built into the user's existing hearth (see Table 5.5). These diverse stove projects provide flexibility and meet diverse needs, fuel requirements, and household incomes and preferences.

As discussed by a World Bank research team, the experience of transferring the KCJ to neighbouring Rwanda provides an important example of technology transfer, evolution, and choice. Laboratory testing of a number of stove designs preceded a large-scale field trial in a Kigali neighbourhood. The KCJ was expected to prove popular, but it did not accommodate Rwanda pots or provide close access to the flame for grilling. A modified version of the KCJ, the Rondereza ("to save") was rapidly adopted by over 25 per cent of the population.40

In addition to the percentage of heat utilized (Table 5.1), the direct financial and quality of life benefits are the crucial test of success for cookstove programmes. In Nairobi, average household charcoal savings as a result of KCJ adoption are 0.18 kilograms per person per day, or over 600 kilograms per family per year; this is equivalent to 1,170 Kenyan shillings (US $64.70 at the 1991 conversion rate). In Rwanda, charcoal use declined by 390 kilograms per year, equivalent to US $84.41

Perhaps the most important aspect of the Kenyan cookstove experience is in the institutional capacity developed by indigenous organizations such as the Kenya Energy and Environment Organization (KENGO) and the Foundation for Woodstove Dissemination (FWD). They have become sources of regional expertise in many facets of improved cookstove design, dissemination, popularization, and follow-up. Along with national and international organizations, they have greatly facilitated the further spread of cookstove programmes in Africa (see Table 5.6).

Table 5.5 - Comparison of Kenyan Improved Stove Designs and Programmes

Stove Description

Institutions Involved



Cost (US$)

Kenya Ceramic Jiko Lightweight metal cladding and ceramic liner: separate firebox and pot rest sections. Primarily for use with

Kengo, FWD a number of and international NGOs; USAID; Ministry of Energy

By over 200 artisans and jua kali copperatives. These groups are manufacturing about 13,600 stoves/month > 700,000 so far

Pre-existing Commercial channels: artisans sell stoves to supermarkets or retailers, or direct to the consumers. 90% sold in urban areas

Varies by stove size, quality, and by vendor: $3 and up)

Kuni Mbili Stove Larger version of KCJ with expanded firebox to more easily accommodate wood fuel

KENGO, the Bellerive Foundation and Rural Technology Enterprises (RTE)

By some of the same artisans as the KCJ; manufacturing about 1,000 stoves/month > 20,000 so far

Programme in the demonstration phase: targeted at rural households that collect or buy wood

Subsidized retail price; true cost of $6-7 & up

Maeneleo, or Upesi Stove standardized liner: baked and then installed with mud and stone surrounding. Variant of Sota stove.

ITDG, GTZ, Ministry of Energy; Home Economics Office of Ministry of Agriculture

Multiple approaches: artisans and women in the informal sector produce liners; installation by extension workers or end-users

Programme in the demonstration phase: transition from extension-based to commercial project underway. Focus on rural households

Liners cost about $1; installed by rural extension teams or end-users

Notes: Jua kali (literally "fierce heat") refers to a loose network of cooperative shops that undertake projects from automotive repair to construction of KCJs. The jua kalis were targeted for early training in cookstove construction and maintenance; it is now a profitable and independent business.

Household Energy Management and Social Change

The fundamental role that energy management plays in family health, nutrition, economic opportunity, and environmental conservation means that improvements in cookstove technology and efforts to disseminate new technologies offer not only opportunities to climb the energy ladder, but also opportunities for positive social change.

The history of cookstove projects shows that energy efficiency is a necessary, but not a sufficient, condition for a new technology to succeed. The part technical, part social criterion of robust efficiency remains a difficult design standard for technologies and for development programmes. However, improved cookstove programmes have benefited greatly from efforts to adhere to this principle by combining intensive interaction and feedback between stove designers and end-users, long project follow-up times, and greater reliance on market and commercial forces.

One important lesson from cookstove efforts to date is that choice and selection - of both technology and implementation methods - are fundamental to meeting the diverse needs of the intended end-users. To some degree, this simply reflects the strength that technology transfer efforts experience when they are designed to support individuals and communities in achieving a diverse set of objectives that are locally determined, and not imposed. An example would be a cookstove training center in which various stove designs and different approaches to managing community workshops are discussed with community leaders, who then select and refine the methods they consider best suited for their particular local conditions.

Funding agencies such as the World Bank, the Global Environment Fund, as well as national and private donors, must tolerate and even encourage the short-term inefficiency of some early cookstove programmes in order to develop a strong indigenous resource base and breadth of experience.42 The mainstream development community has much to learn from the "small is beautiful" or "appropriate technology" approach that emphasizes local knowledge and control of projects, as well as the provision of financial and infrastructure resources that households and poor communities can manage and direct. This approach, however, requires a long-term investment in education that may not initially appear to be warranted in simple cost/benefit terms.

One possible approach that could be implemented by virtually any development organization is to provide small-scale decentralized funding to groups of women, households, or communities to experiment with, and evaluate, a range of energy technologies, including improved cookstoves, solar ovens and food dryers, propane and kerosene stoves, windmills, micro-hydro generators, and photovoltaic systems.43 The resulting technology resource centers, perhaps under collaborative management of the funding agencies and local groups dedicated to researching and promoting new technologies, could also provide wide-ranging technical expertise. This approach of providing a broad selection of technical and managerial resources would ensure that end-users can choose what works for them, rather than what worked best in a laboratory, or what was designed in a grand scheme somewhere else. It promotes technology choice, not dependence.

Table 5.6 - Estimated Number of Improved Stoves in Selected Sub-Saharan Countries, 1994



Burkina Faso




















Source: P. Wickramagamage, Improved Cookstove Programs in East and Central Africa, Draft ESMAP Report (Washington: World Bank, 1991); S. Karakezi, "Disseminating Renewable Energy Technologies in Sub-Saharan Africa," Annual Review of Energy Environment 19 (1994), pp. 387-421; and Stephen Karekezi, "Renewable Energy-Technologies in Sub-Saharan Africa: Case Examples from Eastern and Southern Africa," background brief prepared for seminar, Woodrow Wilson School of Public and International Affairs, Princeton University, April 19,1995.

Although an environment that promotes new, and thus, inherently riskier, technologies is important, market forces and commercial strategies are the final test of whether a project is viable. There is no reason that commercial ventures and tests of market success should not be regarded as allies of "appropriate technology" development efforts - particularly when preceded by a sufficient period of scientific and social "research and development." The most successful cookstove dissemination projects, for example, have capitalized on the market's potential contribution to widespread dissemination: they focused initially on areas where fuels and stoves are already purchased, and then moved into less commercial settings through technical assistance and training, with minimal use of incentives or subsidies.

Ironically, the problem of how to most effectively provide energy services exists under both appropriate technology and mainstream approaches to development. Market-oriented, technology-commercialization development programmes offer little realistic "trickle down," and rural extension efforts have yet to move broadly from subsidy to self-sufficiency. An important goal for future programmes will be to integrate the nurturing, capacity-building features of appropriate technology efforts with the market reach and benefits of scale that can be achieved in programmes that spur commercial interest in small-scale and household energy technologies.


1 Daniel M. Kammen is Assistant Professor of Public and International Affairs, as well as Co-Chair of the Science, Technology, and Public Policy Program, at the Woodrow Wilson School of Public and International Affairs, Princeton University.

It is a pleasure to thank Barbara Saatkamp for research assistance, and Stephen Karekezi, Omar Masera, and Kirk R. Smith for project information and invaluable feedback.

2 J. Woods and D.O. Hall, Bioenergy for Development: Environmental and Technical Dimensions (Rome: Food and Agriculture Organization, 1994).

3 J. Pasztor and L.A. Kristoferson, Bioenergy and the Environment (Boulder, CO: Westview Press, 1990).

4 S.R. Nkonoki and B. Sorensen, "A Rural Energy Study in Tanzania: The Case of Budilya Village," Natural Resources Forum 8 (1984), pp. 51-62; and J. Goldemberg, T.B. Johanssen, A.K.N. Reddy, and R.H. Williams, "Basic Needs and Much More With One Kilowatt Per Capita," Ambio 14 (1985), pp. 190-200.

5 N. Bradley, Women, Woodfuel, and Woodlots (London: Macmillan Ltd., 1991).

6 B. Agarwal, Cold Hearths and Barren Slopes (New Delhi: Allied/Zed Books, 1986); G. Foley P. Moss, and L. Timberlake, Trees and Stoves: How Much Wood Would a Woodstove Save if a Woodstove Could Save Wood? (Washington: Earthscan/IIED, 1984).

7 K. Openshaw, "A Comparison of Metal and Clay Charcoal Cooking Stoves," paper presented at the Conference on Energy and Environment in East Africa, Kenya Energy and Environmental Organization (KENGO), Nairobi (1979), mimeo; K. Openshaw, "The Development of Improved Cooking Stoves for Urban and Rural Households in Kenya," Report of the Beijer Institute (Stockholm: Royal Swedish Academy of Sciences, 1982); S. Connors, "Wood-Conserving Cookstoves: A Short Primer for the Design and Implementation of Woodstoves and Woodstove Projects," Peace Corps/Benin (1987), mimeo; M. Jones, Energy Efficient Stoves in East Africa: An Assessment of the Kenya Ceramic Jiko (Stove) Programme, Report No. 89-01, Office of the Energy Bureau for Science and Technology, and Regional Economic Development Services Office for East and Southern Africa (Washington: U.S. Agency for International Development, 1989); Food and Agriculture Organization (FAO), Guidelines for the Monitoring and Evaluation of Cookstove Programmes (Rome: FAO, 1990); I. Bialy, Evaluation Criteria for Improved Cookstove Programmes: The Assessment of Fuel Savings, Draft Energy Sector Management Assistance (ESMAP) Report (Washington: World Bank, 1991). ESMAP Reports can be obtained from Dr. K.R. Smith, Director, Improved Biomass Cookstove Program, Program on Environment, East-West Center, Honolulu, HI 96848.

8 N.M.H. Graham, "The Epidemiology of Acute Respiratory Infections in Children and Adults: Global Perspectives," Epidemiological Review 12 (1990), pp. 149-78; K.R. Smith, "The Health Impact of Cookstove Smoke in Africa," in African Development Perspectives Yearbook 3 (Muenster: Lit Verlag, 1994), pp. 417-34.

9 S. Raju, Smokeless Kitchens for the Millions (Madras, India: Christian Literature Society 1953); S. Baldwin, H. Geller, G. Dutt, and N.H. Raindranath, "Improved Woodburning Cookstoves: Signs of Success," Ambio 14 (1985), pp. 280-87; Smith and Ramakrishna, Improved Cookstove Programs: Where Are We Now?, ESMAP Report No. 2 (Washington: World Bank, 1991); and D.F. Barnes, K. Openshaw, K. Smith, and R. van Plas, What Makes People Cook with Improved Biomass Stoves? Technical Paper No. 242, Energy Series (Washington: World Bank, 1994).

10 K.R. Smith, The Hearth As System Central, Draft ESMAP Report (Washington: World Bank, 1991).

11 K.R. Smith, G. Shuhua, H. Kun, and Q. Daxiong, "100 Million Biomass Stoves in China: How Was It Done?" World Development 18 (1993), pp. 941-61.

12 World Bank, World Development Report: Development and the Environment (New York: Oxford University Press, 1992).

13 H. Krugmann, Review of Issues and Research Relating to Improved Cookstoves, IDRC-MR152e (Ottawa: International Development Research Centre, 1987).

14 E. Boserup, Women's Role in Economic Development (London: Allen and Unwin, 1970); F. Schumacher, Small is Beautiful: Economics As If People Mattered (New York: Harper and Row, 1973); B. Agarwal, "Diffusion of Rural Innovations: Some Analytical Issues in the Case of Wood-Burning Stoves," World Development 11 (1983), pp. 359-76; B. Agarwal, Cold Hearths; M.B. Anderson, "Technology Transfer: Implications for Women," in C. Overholt et al. (eds.), Gender Roles in Development Projects (Kumarian Press, 1985), pp. 57-78; L. Fortman and D. Rocheleau, "Women and Agroforestry: Four Myths and Three Case Studies," Agroforestry Systems 2 (1985), pp. 253-72; K.R. Smith, "Biomass, Combustion, and Indoor Air Pollution: The Bright and Dark Sides of Small Is Beautiful," Environmental Management 10 (1986), pp. 61-74; and V. Shiva, Staying Alive: Women, Ecology and Development (London: Zed Books, 1989).

15 S.F. Baldwin, Biomass Stoves, Engineering Design, Development, and Dissemination (Arlington, VA: Volunteers in Technical Assistance, 1987).

16 The demand for domestic fuelwood leads to local shortages and often long transportation distances, but it is not a major contributor to deforestation. Commercial logging and agricultural land conversion and alteration are the primary causes of deforestation. See O. Davidson and S. Karekezi, A New Environmentally Sound Energy Strategy for the Development of Sub-Saharan Africa (Nairobi: Africa Energy Policy Research Network, 1992); S. Karekezi, "Disseminating Renewable Energy Technologies in Sub-Saharan Africa," Annual Review Energy Environment 19 (1994), pp. 387-421; and D.R. Ahuja, "Research Needs for Improving Biofuel Burning Cookstove Technologies: Incorporating Environmental Concerns," Natural Resources Forum 14 (1990), pp. 125-34.

17 H. Krugmann, Review of Issues.

18 For an excellent analysis of the design and evaluation of cook-stoves based rigorously on the principles of heat transfer and materials science, see S.F. Baldwin, Biomass Stoves, Engineering Design, Development, and Dissemination.

19 D.F. Barnes et al., What Makes People Cook.

20 These data are an aggregate of several follow-up studies conducted 12-18 months after the various dissemination programmes concluded oven construction or sales sessions. I thank Kirk R. Smith (private communication) for this summary.

21 H. Krugmann, Review of Issues.

22 G. Foley et al., Stoves and Trees.

23 P. Stamp, Technology, Gender, and Power in Africa (Ottawa: International Development Research Center, 1989); I. Bialy, "Evaluation Criteria for Improved Cookstove Programmes"; and P.N. Bradley, Women, Woodfuel, and Woodlots.

24 Based on urban wood or charcoal costs of U.S. $0.30 to $0.40 per family per day. See S. Baldwin et al., "Improved Woodburning Cookstoves."

25 P. Wickramagamage, Improved Cookstove Programmes in East and Central Africa, Draft ESMAP Report (Washington: World Bank, 1991).

26 K.S. Smith, Biofuels, Air Pollution, and Health (New York: Plenum, 1987); D.F. Barnes et al., What Makes People Cook.

27 N.M.H. Graham, "The Epidemiology of Acute Respiratory Infections"; and D.F. Barnes et al., What Makes People Cook.

28 FAO, Guidelines for Monitoring.

29 D.M. Kammen and B. Fayemi Kammen, "Energy, Food Preparation and Health in Africa: The Roles of Technology, Education and Resource Management," African Technology Forum 6(1) (1992), pp. 11-14; P. Young and K. Wafula, "Smoked Maasai," ITDG/KENGO (London, 1993), mimeo; and K.R. Smith, "The Health Impact of Cookstove Smoke in Africa."

30 K.R. Smith, Biofuels, Air Pollution, and Health.

31 C. Barnes, J. Ensminger, and R O'Keefe (eds.), Wood, Energy, and Households: Perspectives on Rural Kenya (Stockholm: Beijer Institute, 1984); G.J. Wells, X. Xu, and T.J. Johnson, Valuing the Health Effects of Air Pollution: Application to Industrial Energy Efficiency Projects in China, Chinese Government/UNDP/World Bank Study (Washington: World Bank, 1994).

32 K.R. Smith, "The Health Impact of Cookstove Smoke in Africa."

33 An important example is the concept of cost per "disability adjusted life year (DALY)," a somewhat problematic measure of the impact of various health and development infrastructure interventions used by the World Bank. The consequences of ARI are felt not only when the disease strikes, but may cause morbidity and mortality decades after the exposure period, causing the loss of many DALYs per person afflicted. The combination of the low cost of stoves and the large DALY impact of woodsmoke exposure makes improved cookstove programmes an excellent investment when measured in cost/benefit terms. For a discussion of the DALY concept, see World Bank, World Development Report, 1993: Investing in Health (New York: Oxford University Press, 1993).

34 R. Hosier and J. Dowd, "Household Fuel Choice in Zimbabwe: An Empirical Test of the Energy Ladder Hypothesis," Resources and Energy 9 (1987), pp. 347-61.

35 S. Connors, "Wood-Conserving Cookstoves."

36 In India, 8 to 10 million improved cookstoves have been disseminated; in China, over 120 million. Both provide lessons for projects elsewhere. A recent World Bank report comparing the two programmes concludes that the Indian programme is problematic; it is characterized by central administration, government involvement in stove production, and high oven costs. The more successful Chinese programme is characterized by government involvement only in dissemination and promotion, leaving stove manufacture and sale generally unsubsidized. (Editor's Note; For a detailed discussion of China's stove programme, see chapter 7, this volume).

37 F.M. Njorge, "An Overview of Improved Stove Dissemination Programmemes in Kenya," Second International Workshop on Stove Dissemination, Antigua, Guatemala, October 1987 (unpublished mimeo); Barnes et al., Wood, Energy, and Households; S. Karakezi and D. Walubengo, Household Stoves in Kenya: The Case of the Kenya Ceramic Jingo (Nairobi: KENGO, 1987); P Wickramagamage, Improved Cookstove Programmes in East and Central Africa; S. Pandey, Criteria and Indicators for Monitoring and Evaluation of the Social and Administrative Aspects of Improved Cookstove Programmes, Draft ESMAP Report (Washington: World Bank, 1991); and D. Walubengo, "Cooking Stoves for Commercial, Sustainable Production and Dissemination in Africa?" Boiling Point 30 (1993), pp. 16-19. Boiling Point is available from the Intermediate Technology Development Group (ITDG), London.

38 P Wickramagamage, Improved Cookstove Programmes in East and Central Africa.

39 E. Hyman, "The Strategy of Production and Distribution of Improved Charcoal Stoves in Kenya," World Development 15 (1987), pp. 375-86; P. Wickramagamage, Improved Cookstove Programmes in East and Central Africa, D.M. Kammen, "Cookstoves for the Developing World," Scientific American, vol.273, pp.72-75.

40 D.F. Barnes et al., What Makes People Cook.

41 F. Hitzhusen, The Economics of Improved Cookstove Programmes, Draft ESMAP Report (Washington: World Bank, 1991); and P Wickramagamage, Improved Cookstove Programmes in East and Central Africa.

42 K. King, The Incremental Costs of Global Environmental Benefits, Global Environment Facility (GEF) Working Paper No. 5 (Washington: World Bank, 1993); D. Anderson and R.H. Williams, The Cost Effectiveness of GEF Projects, GEF Working Paper No. 6 (Washington: World Bank, 1993).

43 M. Dulansey and J.E. Austin, "Small-Scale Enterprise and Women," in C. Overholt et al. (eds.), Gender Roles in Development Projects (West Hartford, CT: Kumarian Press, 1985), pp. 79-134.

6. PV, Wind, and Other Dispersed Energy Sources


This chapter examines the context, barriers, and opportunities that dispersed technologies encounter in the energy market, as another way of addressing the lack of power experienced by most of the population, especially at the household level in rural areas. The electricity sector in Central America is used as a case study to introduce some general concepts that may be adapted to other regions of the world.

Beginning in the 1950s, the energy sector in many developing countries was characterized by the predominance of large centralized power generation facilities financed through a heavy foreign debt burden, large price subsidies, and the absence of both efforts at demand-side management and strong private sector participation. Governments were assumed to be the sole managers and providers of services; national utilities made nearly all decisions about the development and operation of energy projects.

This energy paradigm dominated until the middle of the 1980s, when it began to collapse for a number of reasons. First, because of the economic situation in most developing countries, development banks no longer wanted to lend exclusively or even primarily to large-scale, state-owned, centralized projects; the increased foreign debt from additional external funding would be too difficult under current economic constraints. Second, the global community became increasingly concerned about the environmental impacts of large-scale energy projects and dependence on thermal generation. And third, private developers of power projects and non-governmental organizations (NGOs) became active in establishing new alternatives for addressing development needs.

Throughout the developing world, public utilities have become unable to provide quality services on a continuing basis or to respond adequately to rapidly increasing demand. It is, therefore, essential to assess what alternatives exist for supplying electricity in a sustainable manner. One possible approach is to do nothing, letting demand continue to grow at random, even as public investments in energy decline still further. Under this scenario, the quality of energy services would decline, dependence on thermal plants would increase, and the population and industry would experience frequent blackouts. In short, this option would significantly reduce the quality of life of that portion of the population that still has access, even if it is unreliable, to the public grid. A significant portion of the population would simply not have access at all.

Since the mid-1980s, however, a new environmental paradigm has been emerging in response to declining global economic conditions, the imperative of environmental regeneration, and the demands for a better quality of life for the majority of the population. This new environmental paradigm recognizes that energy is crucial to development. It integrates some aspects of the traditional approach based on grid-connected systems, with dispersed energy technologies, which for the purposes of this paper are defined as "stand-alone," "freestanding," or "decentralized," i.e., not connected to the utility or supplied by unsustainable means.

Dispersed energy systems have emerged as an important alternative to cope with the minimum needs of the poorest sectors, especially at the household level. They are the appropriate solution, where conventional sources of energy are not available or not convenient to use.

In other words, the new environmental paradigm involves new means of transforming and managing energy. It generally includes a number of important components:

· The rates paid by those with access to national power systems are set to be consistent with the long run marginal costs;

· Decisions about both large and small energy projects take account of their potential environmental impact. In particular, attention is given to the high dependence of the majority of people on biomass, especially firewood consumption for cooking and heating;

· Regional and municipal power distribution companies and cooperatives not directly owned by the central governments are often consolidated;

· The inability to meet demand through state-built, debt-financed, centralized projects creates new opportunities for small grid-connected, as well as stand-alone, energy enterprises; and

· Regional and community development organizations provide energy to low-income populations, especially in rural areas, in a sustainable way, with dispersed energy sources.

The Central American Energy Context

Central America consists of seven countries located near the equator. Only half of these countries' combined population of 46 million inhabitants has access to electricity services.


In Central America, like most Third World regions, the energy-demand growth rate is higher than the economic growth rate. As a result, countries often seek high levels of foreign investment to finance construction of large energy projects, to maintain existing state-owned systems, to fund new grid extensions, as well as to pay for the oil imports consumed in operating existing thermal power plants and in the transportation sector. However, not only is foreign funding a heavy load for the economy, but financing the counterpart costs is also an extra burden since allocating money from the national budget requires an increase in tariffs and/or taxes.

Public sector debt is a significant portion of the overall external debt for most Central American countries; in some countries, electricity alone will account for about 45 per cent of the total external debt, projected to the year 2002, if the state-owned utilities assume the development of all on-line projects. Open markets, severe structural adjustment, privatization of public services, and significant reductions in public investment make economic development and socio-economic growth even more difficult.

In recent years, a number of new players have entered the energy market, including private power producers and regional and community service companies, or non-governmental organizations. These new players provide non-conventional energy sources such as small and mini hydro, photovoltaic (PV)-systems biomass-based cogeneration (sugar, rice, sawmills), wind farms, and small wind turbines. They supply energy for small-scale uses, thus, creating improved living conditions for the population. One example is the introduction in Guatemala and Honduras by local community groups, with the support of public utilities, of photovoltaic (PV)-systems for rural home electrification through the creation of small energy ventures at the community level.


The emergence of peace and democracy in Central America has helped to bring about rapid economic growth since 1990. It has also created pressure for improved social conditions for the majority of the population. Together, the growing desire for basic energy and other services and an increase in the available stock of electrical appliances have led to unexpected increases in demand for power.

The growth in demand for electricity in the region as a whole is more than 7 per cent per year. There are, however, significant differences among countries. For example, the percentage of homes with access to electricity varies from country to country, ranging from 40 per cent in Guatemala to a high of 90 per cent in Costa Rica. Despite such differences, the growth in demand for electricity is high throughout the region. In El Salvador, demand in 1993 increased 12 per cent over the previous year; in Costa Rica, where demand was projected to increase 6 per cent from 1992 to 1993, it increased 9 per cent, according to the national utility. With growth rates this high, the region must double its installed electric capacity by the year 2000, a difficult task to carry out under the economic restrictions mentioned above.

Public utilities in general have based their plans for expansion on centralized means of power generation, particularly large hydroelectric projects and conventional grid extensions. However, this approach - carried out mainly in the 1960s and 1970s - has not been enough to keep up with growing demand. In recent years, the lack of scheduled maintenance, planning, and capital investment has led to poor service and a shortage of available power. In Guatemala alone, some 6,000 villages are waiting to be linked to the grid. Honduras had blackouts of up to 10 hours per day in 1994.

One important issue limiting expanded services is the high degree of dependence on fossil fuels. Except for small deposits under exploitation in Guatemala, fossil fuels must be imported into the region. Even Costa Rica, which long prided itself on its 98 per cent reliance on hydroelectricity, now faces serious reservoir depletion problems on existing hydropower plants and serious debt-financing limitations on the construction of new facilities; as a result, Costa Rica, too, is increasingly dependent on fossil fuels.


The demand for such natural resources as food, water, and energy and for services such as transportation and education have a tendency to increase more rapidly than the physical and financial capacity to satisfy them adequately. Central America's current population of some 46 million is expected to double in less than 30 years. In other words, even to keep up with current levels, the supply of resources and services must at least double in that short period of time.

In most Central American countries, the energy establishment has not adequately assessed the long-term availability of power from renewable energy resources. First, severe droughts on major reservoirs and the lack of appropriate planning and maintenance have led to serious power shortages in Honduras, Guatemala, and Nicaragua. Second, the hydrological basins are deteriorating at an accelerated rate; overgrazing and intensive farming of the surrounding slopes without the use of appropriate soil conservation practices have resulted in erosion. Together with the disposal of urban wastes in the rivers, this affects the operation of the large hydro projects and the quality of the water available for producing electric power.

Current conditions in the energy sector also have negative effects on social development in Central America. First, as already noted, only half of the Central American population currently has access to electricity services.2 In other words, there is a large unmet demand for basic energy services, especially at the rural level. Second, firewood consumption accounts for over 50 per cent of total energy consumption in the region, mainly to satisfy the energy needs for cooking at the household level in the rural areas;3 this not only has serious environmental implications, but also affects women's health, education, and opportunities. Central American women must spend a great deal of time in gathering, transporting, preparing, and burning firewood for cooking, a fact that reduces their involvement in education, worsens their health conditions, and limits their opportunities for getting additional income for their families. (Editor's Note: See chapters 2, 3, and 7, this volume, for more detailed discussion of the amount of time women in many parts of the world spend on such activities.)

The Transitional Path: Decentralized Small-Scale Renewable Energy Systems

This context - the economic situation, high growth in energy demand, and environmental and social considerations requiring urgent action - has moved the community of non-governmental organizations (NGOs) to move from the progressive role that a few groups have played in disseminating renewable energy technologies toward more active involvement in addressing the challenges facing the energy sector.

These new players are helping to define the new energy paradigm. They are responding to the need for changes in the way energy is considered, looking not just at energy delivery, but at the whole question of how to integrate energy into social and economic development. They are attempting to catalyze energy as an important instrument for social change and for a range of diverse productive uses, including crop processing and crop-waste disposal, revitalizing artisanal trades, small power sources for education and communications, water pumping for sanitation and agriculture, household electrification, refrigeration, battery charging, heating, etc.


An important part of the new approach to energy is the potential of dispersed energy technologies to meet the monumental energy challenge facing Central America. Of the many available dispersed energy sources in Central America, a number appear particularly promising, including photovoltaic-based home electrification, solar thermal devices, stand-alone wind turbines, small wind/PV-diesel hybrid units, small diesel-power generators, extension of the conventional grid, and micro and mini hydropower.

Photovoltaic-Based Home Electrification

Photovoltaic (PV) electricity transforms sunlight into electricity, storing it in batteries to use any time. A PV system is made up of a module, at least one battery, a charge controller, and an inverter, plus the electrical end-use equipment (i.e., for lighting, communication, refrigeration, water pumping, etc.). It requires minimum maintenance, is well suited for remote locations, and costs approximately $0.75 per kilowatt hour (kWh). By contrast, according to one study by Sandia National Laboratories, the average combined price for batteries, candles, and kerosene is in the range of $US1.00 to $2.00 per kWh, while dry-cell batteries cost on the order of $30.00 to $60.00 per kWh.4 Not only are PV systems less expensive than present alternatives, they can provide an energy source to areas that are not, or cannot be, reached by grid service.

Due to its geographical position near the equator and high levels of sunshine all year-round, PV systems are a cost-effective means of making power available to remote users. This has now been demonstrated by a number of projects. For example, Enersol Associates, a nonprofit group, has incorporated photovoltaics into an innovative financial and institutional system to create a self-sustaining PV energy market in Honduras and the Dominican Republic. Throughout Central America, the PV market is increasing; about 1,500 systems are added yearly, each with an installed capacity in the range of 30 to 50 W each.

Solar-Thermal Devices

Hot water requirements at the household level and in specific productive activities are another need that can be fulfilled by renewable energy technologies. Solar collector technology has matured enough to provide water with output temperatures up to 200 degrees Celsius, depending on the physical characteristics of the materials used, the available solar resource, and the engineering design of the installation. But in residential applications, which do not operate under high pressures, the highest temperatures achieved are on the order of 100 degrees Celsius. In off-grid locations, solar water heaters may not only provide hot water to domestic users for comfort purposes, but may also contribute to improved sanitation in community health centers. In addition, solar water heaters can also have industrial applications; by helping to meet hot water requirements, they can optimize the proportion of energy provided by the solar system relative to the energy provided by other available resources (i.e., gas combustion, electricity from diesel systems, etc.).

The main difficulties this type of system has encountered are technological prejudices in some segments of the population, lack of information about the systems, and the amount of initial investment needed for the purchase of this technology In individual systems for domestic use, the price varies from U.S. $650 to $1,300 (including a 40-50 gallon water tank), depending on the brand name, materials, and installation costs. For industrial purposes, investment costs depend on the size of the system (amount of collector area). However, since the operating cost associated with solar water heaters is virtually nil, the investment cost will be compensated throughout the life of the system.

Stand-Alone Wind Turbines

In many parts of the world, small wind systems (from 50 to 300 kilowatts) provide energy for applications, including village electrification, water pumping, battery charging, small industrial uses, etc. In Central America, however, the use of wind as an energy source is at a preliminary stage.

With the assistance of the National Rural Electrification Cooperatives Association (NRECA) and the American Wind Energy Association (AWEA), a regional programme is evaluating wind potential. This effort consists of plans for wind data monitoring and instrumentation, data processing and evaluation, and site-specific resource assessment. Although the programme has identified several sites at which wind energy could potentially be utilized, no commercial market has yet been developed for small remote power applications. A few old systems (the multi-bladed farm windmills) are under operation around the countryside in Guatemala and Costa Rica, mainly for water pumping for irrigation and potable water.

Small Wind/PV-Diesel Gas Hybrid Units

In a number of places, combining photovoltaic or wind systems with diesel offers potentially greater benefits than stand-alone renewable systems. Such hybrid units offer greater reliability, especially for remote applications such as land-based and naval communications, park management, etc., while at the same time attempting to minimize the use of the diesel fuel. In these combined systems, the electrical energy generated by the wind turbine or the PV array is converted to chemical energy in the batteries, which in turn can be converted to electricity for later use. The diesel/gas generator can be used either to charge the batteries or to supply electricity directly.

In such combined systems, it is preferable to have control mechanisms that permit turning off the diesel generators whenever the renewable energy technologies can supply the load, since a continuously running diesel engine operates very inefficiently when supplying a small fraction (less than 40 per cent) of its rated capacity. In hybrid systems that supply electricity to small villages, the electric power is produced in AC and fed directly to the load. Storage systems (such as batteries and other hydro-pneumatic systems) act as "buffers," maintaining a stable output during short periods of time, such as when low winds occur. In much smaller hybrid power systems, with outputs at the household level, the energy is produced in DC and sent entirely into a battery bank that in turn feeds a DC load, or an AC load through an inverter.

Small Diesel-Power Generators

Conventional diesel-generating systems have been the traditional way to address the problem of lack of electricity in remote or off-grid applications. They can be rapidly installed, and provide a good solution to common electric power shortages and blackouts in the region. The main advantage of this old and proven technology is its reliability, but the costs associated with this technology (e.g., initial investment, imported fuel, transportation) are not suitable for low-income villages dispersed throughout rural areas. These systems can, however, solve the problem of providing energy for such activities as agroprocessing industries, small municipal electric enterprises, etc.

Extension of the Conventional Grid

Extension of the conventional grid can help ease access to electric energy use not only for residential lighting, but also for productive activities in rural areas. It can provide energy options for small shops, artisans, micro-enterprise development, small industrial manufacturing, etc.

Several NGOs recognize the development implications of these activities and are offering technical management assistance and loans for extending conventional electric grids and easing access for individuals and groups. This approach addresses underlying social development needs associated with energy services by helping to implement programmes that promote productive uses of energy, as a complement to electrification efforts. It looks beyond the potential market for energy suppliers and focuses instead on the actual needs that the provision of energy seeks to fulfill.

NGOs are best equipped to promote this type of programme, and a few of these are currently in place in Central America, like the successful cases of GENESIS (see Box 6.1) and FUNDAP in Guatemala, ADHEJUMUR in Honduras, etc. One of the main findings of existing programmes is that, by providing basic electric equipment to already existing enterprises in newly electrified villages, the number of jobs provided by these enterprises can readily be tripled.5

Micro and Mini Hydropower (up to 1000 kW)

A hydraulic turbine connected to a generator can convert water flows into electricity. This technology is the most developed due to the geographic and climatic characteristics in all Central American countries. Since the scope of this study is limited to nontraditional stand-alone systems for remote locations, this technology will not be discussed further.

In addition to electricity, other dispersed energy sources in rural areas include dissemination of improved firewood stoves, solar cookers, solar crop drying systems, etc. These dispersed energy technologies are all too small to attract conventional sources of funding.

BOX 6.1

GENESIS: A Case Study in Success

GENESIS is a nonprofit, private-sector organization created in 1988. It has an exceptional track record in credit programmes for micro-enterprise development in Guatemala, giving financial assistance, management advice, and capacitation. Its general objective is to strengthen and develop micro enterprises by helping to increase incomes and generate job opportunities - by promoting the socio-economic situation of workers and their families. Its active loan portfolio has grown from under $50,000 to $3,500,000 in six years.

By early 1995, GENESIS had provided more than 37,000 loans, creating or strengthening nearly 10,000 jobs and benefiting nearly 60,000 family members. The impact on the beneficiaries has been very positive. Net incomes for enterprises with individual loans increased an average of 74 per cent, and 20 per cent in the case of loans provided to groups. Net profits for individuals increased an average of 72 per cent, and for groups an average of 40 per cent; and net assets increased 33 per cent and 48 per cent, respectively, for these same categories. Women have benefitted especially in the well-established groups.

In September 1992, GENESIS initiated a programme to finance productive uses of energy for micro entrepreneurs with access to the grid. In 1993, the programme was expanded to include grid extension to communities that could not afford the investment of interconnection. In 1994, GENESIS initiated a parallel programme to finance rural electrification through decentralized renewable sources for communities for which grid extension was not a viable alternative.


The large unmet demand for basic energy services in rural areas has prompted a number of efforts to create markets for small-scale energy sources, particularly photovoltaic projects for home rural electrification. Although these projects vary from country to country, and from project to project, a number of generalizations can be made.

Private Power Generation Investors

This category includes all those projects that primarily focus on generating electricity for captive uses or for sale to the national grid, mostly oriented toward small hydropower (above 1000 kW), biomass-based cogeneration (sugar, rice, sawmills, etc.), large-scale wind power systems (wind farms), geothermal, and of course, private power generation projects based on diesel oil.

Their common innovative feature is the participation of the private sector in the previously monopolized energy generation market. Because this is essentially an opening market, developers are forced to find new financial mechanisms, mainly foreign capital. Local capital is generally not available for investing in this kind of activity.

The viability of these projects is linked to the changes in the electric regulatory and legal frameworks; however, only in Costa Rica is the new legal framework reasonably clear yet.

Local Development Organizations

This category includes all those players with the innovative goal of integrating energy into rural development. These players tend to include mainly municipalities, cooperatives, and non-governmental organizations. In contrast to projects by private investors, projects initiated by local development organizations are primarily directed at decentralized energy supply systems. Their aim is to meet the social and productive needs of off-grid communities through non-traditional energy services and to promote renewable energy and energy-efficient technologies.


From the sustainable development perspective, local development organizations contribute to the transition to a new energy paradigm in three important ways:

1. They are concerned about a just distribution of energy services and improvements in quality of life. Local development organizations can make a significant contribution toward social equity by rectifying the deficiencies of the centralized and urban-centered focus of public utilities throughout Central America. An emerging focus for these efforts is rural electrification, i.e., providing energy services to communities and villages isolated from the grid. Some promising approaches include the establishment of small energy enterprises, the establishment of credit programmes to finance grid extensions, and the dissemination of dispersed renewable energy technologies appropriate to local resource availability.

2. They regard energy as a means, not an end, in the development process. The concerns of local development organizations go beyond increasing the amount of energy generated and delivered toward enhancing the capacity to derive social and economic benefits from the integrated use of existing and new energy sources. Essentially, this requires remedying wasteful or inefficient use of energy before generating more energy The goal is not just to increase the amount of energy being produced, but to increase the benefits that derive from access to energy

This approach requires reducing energy consumption through the introduction of more energy efficiency standards on appliances, lighting, and buildings, as well as implementing productive uses of energy as a complement to rural electrification. Energy provision, in other words, is linked to the social context and consumer behavior.

3. They contribute to environmental and financial sustainability by seeking to reduce the negative impacts of conventional energy generation and to provide cleaner alternatives. Local development organizations have gotten involved with energy issues because of the need to decrease the environmental degradation associated with conventional energy generation. Their potential to promote dispersed energy sources and energy efficient technologies is immense since these are appropriate to the local resource available and adapted to social, economic, and cultural conditions.

Furthermore, local development organizations contribute not only by promoting renewable energy technologies, but by formulating and validating new approaches for making the environmentally superior energy solutions a viable facet of the new paradigm. This requires going beyond the conventional mentality of international assistance and technology transfer; it requires recognizing local capabilities for making improvements in their own quality of life. A big contribution to this effort, for example, is the work of groups like the Biomass Users Network (BUN) in Central America. With the support of the Rockefeller Foundation, BUN and the E&Co Initiative (discussed below) are fostering early stage development of commercially viable environmental enterprises that are currently outside the scope of interest of conventional financial institutions.

The benefit of this approach is that once the initial demonstration phase is complete, such enterprises may then attract private capital. It assures local and international financial institutions of the validity of these small enterprises, especially if small-scale and initial risk concerns are compensated through project aggregation and in-depth evaluation.

On the other hand, there is a need for local capability development and strengthening of the terms of international exchange. In a worldwide open market scheme, new mechanisms for supporting the takeoff of commercially viable projects and financing sustainable resource management are needed.


The various energy initiatives of local development organizations throughout Central America all faced a number of significant barriers:

· The existing gap between what conventional sources of capital are willing to finance and what the new enterprises seek to do.

· Lack of players experienced in linking small-scale projects to available funds. Local development organizations should facilitate a process that incorporates community-level participation from the beginning and enhances the community's access to funding sources.

· Lack of human resource and organizational capacity to turn good ideas into proposals. In other words, projects must be well-defined and involve participants, who are capable and organized to proceed. Most project proponents need strengthened capacities to clearly define projects.

· Language differences. The lack of command of English by project proponents and the lack of command of Spanish by funders forces too much time to be spent on document translations.


At the international level, most funders and major donors are changing the way they assist developing countries. They are moving from providing core-funding to supporting projects that can be self-sustaining, using the following criteria for small energy enterprise:

1. Innovation. Increasingly, projects must employ technologies or techniques that show the potential of new approaches to energy production, transportation, and end-use. In addition, in view of the need to generate local capacity in the formulation and execution of sustainable development ventures, projects should have innovative institutional and financial framework that will lead to the establishment of a new enterprise.

2. Integration. In order for a dispersed energy technology to achieve market penetration, the energy enterprise should integrate technical, legal/institutional, and financial aspects. These can also encourage the local banking community to participate in financing the dispersed energy sources once their effectiveness and viability have been demonstrated.

The technical considerations that must be integrated are specific to each project. The technologies applied should be well-established in both industrialized and developing countries, although the projects should be innovative in how they are carried out.

The institutional aspects that must be integrated consist of the conditions that must be observed in order to be able to operate legitimately in each country, the legal considerations in establishing contracts and agreements with other players, and the steps necessary to establish a structure that will progressively ease the development of new projects.

The financial aspects that must be integrated include selecting the best financial mechanism to manage the project's disbursements, repayments, and terms as well as attracting additional sources of capital investment.

3. Diffusion. The development of a small energy venture should have adequate support not only from the potential beneficiaries at the community level, but also from the political actors in the national context, especially in the energy sector, in order to make it replicable either in the same country or elsewhere.

4. Demonstration and Validation. Projects must have the potential to be self-supporting and, if successful, to attract private sector investment that can eventually repay this early support. The central goal of early stage enterprise development is to formulate new approaches that make environmentally superior energy solutions commercially viable and able to access private capital. Support for early stage enterprise development involves activities like:

· providing technical expertise and support to the project developer in securing bank credit and in writing the project proposal;

· providing pre-investment funding;

· setting up revolving fund mechanisms, in which the repayments on initial loans can be used by other borrowers for other renewable energy ventures;

· bundling small projects together to create a package large enough to interest conventional financial institutions; and

· providing financing via the equipment supplier and other entities operating in concert with the supplier in order to minimize transaction costs.

5. Environmental Benefit. Projects must also offer clear environmental benefits that are demonstrably more successful economically than the local alternative.

Photovoltaic Systems for Rural Development in Guatemala: A Case of NGO/Utility/Financial Entity Collaboration

The following case shows a successful collaborative effort to make electric energy available and affordable to low-income communities in the outskirts of the City of Guatemala. This example illustrates that support for enterprise development can act as a catalyst, enabling innovative concepts to overcome financial, technical, and legal/institutional barriers in order to make energy services and the related social benefits accessible to more people.


Guatemala's electricity sub-sector consists of the National Power Generation Utility (Instituto Nacional de Electrificaci INDE); the Guatemalan Electric Enterprise (EEGSA), which distributes power to three departments (or states) around the capital, Guatemala City; municipal electric enterprises that distribute power to rural municipalities; and private energy enterprises that generate and distribute power on a private basis to other areas in the country. INDE is the primary institution in charge of power generation, transmission, and electrification for most rural and urban areas. As of 1991, the Guatemalan power grid serviced 40 per cent of the population, including 16 per cent of the rural population.6

The average electricity consumption per capita is 125 kWh/inhabitant/year, about a tenth of the Latin American average of 1,200. Table 6.1 summarizes the percentage of homes without electricity in the twenty-one departments that make up the Republic of Guatemala.

Through concerted efforts, such as the Third National Rural Electrification Project (PER-III), the Guatemalan government has sought to increase the coverage of rural areas. PER-III aims to bring electricity to 280 rural communities that do not have services, and to expand the available services to 95 other communities by 1996. But the financial barriers confronting the electricity sub-sector, the growing energy demand in the rural areas, the deterioration of INDE's large-scale power plants, and the physical constraints to serving a dispersed population through a centralized power system, all indicate that the proportion of the Guatemalan population unserviced by the national grid could increase, possibly reaching two thirds of the country's inhabitants by the turn of the century.

TABLE 6.1 - Homes Not Serviced by Electricity in Guatemala


% Unserviced


% Unserviced

Alta Verapaz








El Quich/TD>








San Marcos


El Progreso






Baja Verapaz
















Santa Rosa


Source: International Fund for Renewable Energy and Efficiency (IFREE), Central American Renewable Energy and Energy Efficiency Project, Country Study: Guatemala (March 1994), p. 24.

Facing the Challenge: EEGSA's Approach

The Guatemalan Electric Enterprise is responsible for power distribution in the departments of Guatemala, Escuintla, and Sacatepez. EEGSA is a private corporation, although the large majority of its shares are owned by INDE. Because its service area surrounds Guatemala City, it has greater access to a variety of services (including electricity) than the rest of the country; nevertheless, a large proportion of homes in this area, especially in Escuintla, do not have access to grid power.

Furthermore, EEGSA's Rural Electrification Department estimates that it is only able to service 5 per cent of the nearly 100 new requests for electrification it receives every year because of the high costs of grid extensions. This situation was aggravated in November 1994, when EEGSA was forced to begin rationing electricity to areas it already services because of problems in meeting existing demand. In this power supply crisis, costly grid extensions to provide power to dispersed unserviced users are likely to have lower priority than meeting demand in already serviced areas.

Fortunately, EEGSA's Planning Department has chosen to regard the problem as an opportunity to introduce decentralized renewable energy technologies that can meet the basic energy needs of remote rural homes without increasing stress on the power grid. In this effort, they have been supported by CrediEEGSA, a credit corporation founded in March 1993 and affiliated with EEGSA. One of CrediEEGSA's main objectives is to provide financing, without subsidies, to unserviced communities in EEGSA's area of influence to enable people to acquire energy services.

The Role of Photovoltaic Systems

EEGSA's Planning Department became interested in the concept of solar photovoltaic (PV) systems to provide basic energy services to communities on the outskirts of Guatemala City that were at a considerable distance from the grid. It identified a number of advantages to this technology: it is modular, that is, initially small systems can be expanded as the household's energy demand and ability to pay increase; it has a long useful life since PV systems have no moving parts that can wear away; it has low maintenance costs since the only component that needs routine care is the battery; easy and quick installation allows a home system to be fully installed in under a day; and it creates less air or water polluting emissions since no combustion processes are involved.

The standard stand-alone system used for basic electrification of rural homes in Central America consists of one or more photovoltaic panels, each capable of converting solar radiation into 35 to 100 watts of electric power, depending on the panel rating, under favourable atmospheric conditions; one or more 12 volt batteries similar to those used in cars or motorboats to store the electricity for later use (for example, for lighting at night); control units to regulate battery charge and protect the system; efficient fluorescent lamps; and an optional DC to AC inverter for running small appliances.

Increasing the number of panels or the number of batteries can broaden the possible uses of energy, but it also increases the cost. The size of the system, and particularly the number of batteries, is designed according to how much solar radiation is available on site; if the site tends to have relatively long periods of insufficient sunlight, then the storage capacity of the batteries needs to be higher to maintain system operation. The user also needs to control how much power is consumed in order to make the best use of the available energy and to prevent the battery from discharging below the minimum working charge because this could greatly decrease its useful life.

In some cases, rural dwellers are already familiar with how car or boat batteries operate, or they may even be using them for powering radios or lights at home and taking them periodically to a nearby town for recharging. This makes the introduction of PV technology easier because the customer is already used to working with DC power. Conversely, PV systems are not cost effective, where the power demand can be met by extending the power grid or where users are accustomed to a wide range of uses of grid electricity. Electricity from small PV systems cannot support such uses as thermal showerheads, electric ovens, or large appliances, and conventional appliances cannot be used without having a DC to AC inverter. However, for many rural dwellers, PV is the alternative to having no electricity. Once they purchase a PV system, they have a guaranteed power supply and are not subject to blackouts due to excess demand on the grid. Moreover, they do not have to pay anyone for the electricity they consume, or for candles, kerosene, or dry-cell batteries.

Figure 6.1 - Economic Break-Even of Photovoltaic* Installation

Source: Guatemalan Electric Enterprise (EEGSA), 1993.

* PV is to be preferred for the combination of parameters located above the respective bars in this figure.

EEGSA undertook a pre-feasibility study to assess how viable PV systems would be. They compared the economic feasibility of introducing photovoltaic systems to a remote village with that of extending the power grid. The study showed that financial feasibility of PV systems over grid extensions is determined by four factors: distance from the grid, number of homes, dispersion of the homes (average distance between each home), and energy consumption per home. An increase in the number of homes or in the energy consumption per home makes grid extension more feasible. Conversely, an increase in the dispersion of the homes and the distance from the grid makes PV systems more feasible. In addition, since the buyers of PV systems need only pay for the investment cost of the system and not for the energy they consume, once they have purchased the system, the price per kWh sold by the grid also affects the feasibility of installing a PV system. Figure 6.1 compares the economic viability of PV systems and grid extension for two different consumption levels (62 kWh/month and 36 kWh/month); for the points located above the shaded areas, at both consumption levels, the PV-based home electrification option is economically more feasible than grid extension.

EEGSA then identified a number of villages along the Motagua River Basin, about 50 kilometres north of Guatemala City, along the boundary between the departments of Escuintla and Baja Verapaz, that fulfilled a number of the requirements that would make PV systems feasible. The villages were all more than 10 kilometres from the power grid, their requirements for power consumption were about 12-15 kWh/month, they had dispersions of about 100 metres, and the number of households ranged from 100 to 300 per village. The economic calculations suggested that in this situation, the cost of installing PV systems in some of these villages could be as low as one third the cost of extending the grid.

In order to encourage local villagers to invest in the new solar technology, EEGSA and CrediEEGSA, with the assistance of several international agencies, carried out a pilot project to introduce photovoltaic systems for rural electrification. For this one-time pilot project, they sought one of the lowest income villages and offered to subsidize two thirds of the costs of the PV systems. CrediEEGSA provided credits to the users for the remaining third of the costs, which the users were required to re-pay over two years. Through this pilot project, EEGSA was able to install 42 PV systems in the village of San Buenaventura in the Department of Guatemala.


The next step for EEGSA in making PV systems as a commercially viable substitute to costly grid extensions was to develop the financial mechanisms that would allow rural communities to cover the full costs of decentralized energy systems, without the need for paternalistic subsidies. However, EEGSA was limited by a lack of available funding for such an initiative; the Guatemalan banking system and the traditional international assistance programmes were not interested in the concept of providing low-income farmers with small credits to finance a new technology for providing electricity in remote areas. They considered it a high risk venture with a high administrative and paperwork load for a small sum of money. There were also no conceptual models to guide the management of a commercial venture of this kind.

However, the potential of EEGSA's PV rural electrification project was readily apparent to the Energy Enterprise Development Initiative for Central America (E&Co. Initiative). The E&Co. Initiative is a new investment venture being carried out by the Biomass Users Network's Regional Office for Central America and the Caribbean (BUN-CR) with the support of the Rockefeller Foundation; its objective is to nurture early stage energy enterprises in developing countries and help them evolve to the stage where they can be considered for funding by conventional financial institutions. BUN-CR is a nonprofit, non-governmental organization working out of San Jose, Costa Rica, whose mission is to support community groups and small enterprises that are actively involved in the productive use of renewable energy and biomass resources, as a means of advancing social and economic well-being in the Central American and the Caribbean regions.

BUN-CR saw the EEGSA project as the core of a revolving fund that could operate for a specific period of time supporting the commercial introduction of autonomous PV systems, and then expand to support the development of a wider range of commercially viable renewable energy ventures throughout Guatemala. Through an initial evaluation, BUN-CR analysts agreed with EEGSA and CrediEEGSA officials that the EEGSA project met all the criteria of the E&Co. Initiative. The project involved new players (both energy users and funders) in the provision of energy services; the revolving credit fund was an innovative means for making energy accessible to remote locations without subsidies; it introduced new environmentally friendly technologies, providing a substitute for diesel generators and dependence on candles, kerosene, and batteries for lighting; and the results could be replicated to other developing regions.

In July 1994, EEGSA and CrediEEGSA staff prepared a proposal for funding from the Rockefeller Foundation under the E&Co. Initiative, with the assistance of BUN-CR. The request was for US$65,075 to finance the installation of no less than 95 PV systems, in the La Canoa Village, on the Motagua River Basin. In accordance with this proposal, CrediEEGSA has been contracted to administer the $65,075 fund for six years.

Each of the players will have a specific role in project implementation. CrediEEGSA's administrative functions will include signing the credit agreements with each user and handling the collection of repayments and the monitoring of the accounts for each credit, ordering the purchase of the PV systems on behalf of the users, retaining the bill of purchase as security for the credit and, if necessary, repossessing the equipment in case of default. EEGSA will be contracted by CrediEEGSA at zero-subsidy costs to provide the design of the PV systems, to procure the equipment, and to carry out the installation, supervision, and training of the local committee. BUN-CR will supervise the operation of the fund and promote the dissemination and replication of the experience at the regional level. In the communities, Local Solar Energy Committees will handle training of individual users, organize the collection and the trips to Guatemala City for the monthly payments, and carry out routine inspections and maintenance of the systems.

The financial terms for the project take account of both Guatemalan financial market conditions and the project's objective of making energy services available to low-income rural dwellers. The cost of each individual system will range from US $560 to $670. With financing for up to three years at a variable interest rate that will start at 18 per cent and be adjusted for local inflation, the purchasers will have to make monthly payments ranging from $12 to $24, depending on the size of the system and their downpayment. CrediEEGSA will pay interest of around 12 per cent on the fund's balance and charge a transaction fee for collecting the payments and administering the fund. It is estimated that after 36 months, the fund's accumulated revenues will be $94,000. This estimate allows for a 5 per cent delinquency rate, based on CrediEEGSA's prior record of a delinquency rate of less than 2 per cent. All project costs, including management of the fund and all resources allocated by EEGSA, will be internalized into the cost of the system paid by the user.

Financial analysis shows the project is sustainable. At the end of the third year, the present value of the fund will be $77,925. Therefore, the net present value of the accumulated investment will be $12,850. The project has a payback period of approximately 2.5 years and a benefit to cost ratio of 1.20. In keeping with the E&Co. Initiative's objective of involving new players in innovative energy services, a major private Guatemalan bank has started to follow the project's progress with great interest, and could possibly consider investing capital in subsequent replications of this experience.


As the pilot project has demonstrated, the introduction of PV systems will yield a variety of quality of life improvements to households that purchase a system, and to the community as a whole. For EEGSA, the main goal is providing clean, reliable lighting to the households in the community. The PV systems will provide better quality light, while simultaneously eliminating a source of pollution and a fixed cost of about $9.00 per month for candles, kerosene, and batteries. Electric light can increase the hours available for work, recreation, and education. This is especially important in poor rural communities in Guatemala, where the literacy rate is very low, and both children and adults have little chance to study during the day.

In addition, the PV systems designed for this programme can power radios, small black and white television sets, and small appliances like blenders for household and commercial uses. The project also provides training to the users in the management of their energy systems, which is vital since PV power cannot be squandered as often happens with grid electricity; and it strengthens the local institutions that will handle basic system inspection and repairs. Furthermore, the project aims to promote micro-enterprise development in the community, with activities ranging from small-scale productive uses of the new energy source to the creation of a maintenance and spare parts shop for the upkeep of the systems.

An equally important outcome is the empowerment of the community to participate in credit programmes. Many credit applicants say that they had never before had a bank account, much less considered themselves eligible for reimbursable financing. Traditionally, they thought their only option was to wait for the government to extend the grid (in some villages, the wait is estimated to be seventy years). However, through the application process, they have attained self-confidence and experience in dealing with financial institutions, and after the conclusion of the project, they will have a positive credit record that will help them in pursuing other productive activities.


Dispersed energy sources can partially provide the energy to sustain the social and economic change needed for development. By moving away from waiting for all the answers from a single player, the public utility, it is possible to create a new transitional paradigm in which, under certain circumstances, systems that use dispersed sources of energy offer lower marginal costs for supplying power for social change than centralized energy facilities.

In non-grid connected villages, dispersed energy systems offer a quick, economic, and reliable answer to the need for power. The rapid decrease in the cost per kWh of decentralized energy technologies, and the opening of commercial markets on a global scale, represent a great opportunity to develop new schemes. Converting sunlight into electricity through PV module arrays at the household level offers a good example. Several programmes are already underway in the developing world, particularly in countries in which the public utility has been unable to cope with the growing demand for power in due time by traditional means.

The experience of these programmes offers a number of lessons:

1. A quick response is needed to meet the energy requirements of development and of improving the quality of life of the people of developing countries. No single measure can fully meet these requirements. The role of local governments and public utilities can be complemented with the participation of local development organizations and private developers.

2. Socio-economic development is taking place in the context of more open market economies and a growing number of competitors from outside the region. Indigenous financing systems are unable to fully meet the capital requirements of the less developed countries' economies. So, there is a definite niche for stimulating investment in environmentally friendly technologies and innovative approaches for providing energy services on a sustainable basis; this investment can come from private power investors, private banks, large development banks operating through their private-oriented initiatives (such as the International Finance Corporation), the European Community, etc.

3. Although local development organizations must be involved in energy issues, their role should be clearly defined and their scope of work well integrated into the new energy paradigm; otherwise, they may distort the new market of decentralized energy systems. False expectations in terms of unclear benefits and the continuation of paternalistic practices should be avoided.

4. Enhancing the quality of life in rural areas can help reduce the pressure caused by the unsustainable use of the rural natural resource base and decrease people's migration to the cities. In this way, dispersed energy sources help to address the major causes of social and environmental degradation in developing countries.

5. It should not be overlooked that firewood is pivotal to the rural energy economy; thermal uses of dispersed energy sources, such as solar cookers and agriculture crop dryers, have a niche to fill in using energy as an instrument for a better quality of life.


1 Josa. Blanco is Regional Director, Biomass Users Network, Regional Office for Central America and the Caribbean (BUN-CR), Guadalupe, Costa Rica.

2 Central America Renewable Energy and Energy Efficiency Project (San Jose, Costa Rica: IFREE/BUN/CISAT, March 1994), p. 4.

3 Conferencia Regional de Alto Nivel de Lideres Centroamericanos de Sector Energia (San Jose: Los Alamos National Labouratory/INCAE, May 1991), pp. 184-89.

4 Lisa W. Shepperd and Elizabeth H. Richard, "Solar Photovoltaics for Development Applications," Sandia National Laboratories (August 1993), p. 3.

5 Genesis Empresarial, Evolucion y Resultados (Guatemala: September 1992), p. 22.

6 Ing. Olga Dalila Diaz Paz, Beneficios Econos en Viviendas Electrificadas en el Area Rural (Instituto Nacional de Electrificacion, INDE, April 1991), p.2.

7. Renewable Energy Benefits Rural Women in China


The availability of energy is an important pre-condition for developing the national economy and improving people's living standards. Despite its large population, China has a weak industrial, scientific, and technological base. In rural areas, the level of commercial energy consumption per capita is only about 0.12 tons of coal equivalent (TCE), and the quality of existing energy resources is often poor. In short, both the quantity and the quality of existing energy resources are inadequate to meet the industrial and agricultural needs of the country.

Improving both the availability and utilization rates of energy resources is an important strategic task that will have significant impact on China's ability to promote sustainable human development, that is, development that simultaneously promotes economic growth, improves people's living standards, and protects the natural resource base essential to the country's long-term future.

Eighty per cent of China's people live in rural areas, where the shortage of fuel is most acute. The unavailability of energy in vast rural areas is the key factor hindering the development of the rural economy and preventing improvement in people's living standards. The extent to which China can meet the growing demand for energy in these areas in ways that are sustainable will significantly affect its economic growth and the health and well-being of its people.

Fuel Shortages and Deforestation

Before 1979, more than 70 per cent of the fuel used by farmers came from biomass - crop stalks, straws, grasses, and animal dung, which were burned directly. The efficiency of utilization rate of this form of energy is only 10 per cent, thus, resulting in significant waste of natural resources. At the same time, nearly half of farm households suffered shortages of available fuel for three to six months of the year. They resorted to collecting every conceivable kind of burnable material, creating serious environmental and human consequences.

First, because of the loss of large amounts of forest, vegetation was damaged, the soil became sandy, and grasslands deteriorated. The loss of crop stalks and other materials that could be used as feed for animals, as fertilizer for farmland, or as industrial raw material directly affected the production of agriculture, forestry, livestock, and industry.

Second, inefficient direct burning of fuelwood in traditional stoves increased emissions of carbon dioxide and flue gas into the atmosphere, damaging the balance between carbon and nitrogen in the agro-ecological system. This, in turn, also contributed to bringing about long-term climate change.

Third, because women always performed the household chores, such as fuelwood collecting and cooking, they were particularly affected. They shouldered the burden of collecting wood from ever greater distances and suffered from indoor air pollution, a condition aggravated during the early summer rains when wet wood did not easily bum. Eye disease was common. The fuelwood shortage meant that people often could only eat one or two hot meals per day, and gastric and intestinal disease seriously affected health.

Solving the fuelwood shortage and changing the structure of fuel are top priority development tasks in China, both to increase agricultural production and to improve farmers' livelihoods. Since the very founding of the People's Republic of China, but particularly since the introduction of more open policies, the government has made rural energy construction a high priority. The interests of both the state and the people dictate attention to exploitation of new and renewable energy sources as well as to conservation and rational utilization. China's government describes its policy as "suiting measures to local conditions, making different sources mutually complementary, utilizing in a comprehensive way and seeking for benefits" and "putting equal stress on exploitation and conservation."

China's rural energy development has achieved great progress and received worldwide attention. It is based on seven basic points:

1) popularizing coal- and fuelwood-saving stoves,
2) developing high-grade biogas,
3) developing small hydropower,
4) exploiting and utilizing solar energy,
5) developing fuelwood forests,
6) developing and utilizing wind energy, and
7) developing and utilizing geothermal energy.

These measures have significantly improved the quality of life in rural areas, particularly for women, who are disproportionately impacted by energy shortages.

Coal- and Fuelwood-Saving Stoves

One of the first measures taken was to promote widespread use of coal- and fuelwood-saving stoves in rural areas. The improved stoves require relatively little investment, are more convenient to use, use less fuel, and emit little smoke. The heat efficiency of these stoves is more than 25 per cent - one and a half times as much as the old stoves.

Women were particularly enthusiastic, quickly recognizing the stoves' greater convenience and efficiency Women often wanted to be among the first in their communities to have the improved stoves in order to have better conditions for their families.

By the end of 1993, some 158 million farm households, accounting for 69 per cent of total farm households, had the improved coal- and fuelwood-saving stoves (see Figure 7.1). This has had significant health and environmental benefits. Women no longer suffer from the extreme smoke created by the old stoves. In areas where coal had high fluoride content, fluoride poisoning from smoke has been eliminated. Farmers can now eat hot meals throughout the day. Because less fuel is needed, the amount of time women spend gathering fuelwood has been reduced, lightening their burden, giving them more time for other economic activities, and reducing pressures on the environment. The total amount of biomass consumed has declined and forest resources are better protected.

The Extension of Biogas

Biogas was first introduced in China in the 1930s, and has been seriously developed since the 1980s. By the end of 1993, 5.25 million farm households had biogas digesters (see Figure 7.2), with an annual production of 1.18 million cubic metres. Biogas has a heat value of 5,500 kilocalories per cubic metre, higher than that of coal gas in urban areas.

Figure 7.1 - Coal- and Fuelwood Saving Stoves

Biogas digesters provide time and labour savings. In some areas, they have become a necessary prerequisite for marriage. Girls want them as part of their dowries, or they may ask their future husband's families to build them as part of the marriage agreement. Biogas digesters are considered "priceless assets."

In the northern part of China, where the weather is quite cold, "four-in-one" systems have become popular. The "four-in-one" model provides multiple functions; for example, a plastic-roofed greenhouse may be built within a courtyard, with a pigsty or hen house at one end of the greenhouse, a toilet at the other, and a biogas digester beneath the pigsty. The unit, thus, combines biogas production, poultry or pig breeding, vegetable and fruit production, and fertilizer collection in a single plot. All the activities rely on and promote each other, to form a cycle. Meat, eggs, and vegetables can be produced and supplied to the market even in cold seasons. Women are able to develop productive agricultural businesses that earn them additional income, and the rural economy benefits from additional activity. Thus, biogas provides a means of integrating agricultural resources; its many functions and efficiencies help in creating an ecological agricultural system.

Figure 7.2 - Household Biogas Digesters

Ecological agriculture has contributed to total agricultural production, helped to protect the environment, and provided women with income-earning opportunities in the form of silkworm production, mushroom culturing, pig and poultry production, fish farming, weaving, sewing, and embroidery. When they are freed from their traditional heavy chores, women become actively involved in crop planting, industry, and other income-generating activities. A number of rural women have been awarded the title "woman expert" at "double study, double competition" (study culture, study technology, competition for progress, competition for contribution). Women's work in afforestation and other areas is recognized by these and other awards given by provincial, municipal, and district governments.

China also has built over 600 large and medium-sized biogas plants that use organic waste from animal and poultry farms, wineries, and food factories. Their combined capacity is 220,000 cubic metres, which can process about 20 million tons of organic waste annually. The biogas produced services 84,000 households, replacing traditional coal and fuel.

In accordance with its commitment to environmental improvement, China has also built 24,000 biogas purification digesters to process daily waste water in urban areas. Their total capacity is 940,000 cubic metres, which can treat daily waste water for 2 million people.

Biogas development has significantly improved living standards in China's rural areas, where biogas has been popularized and farm households can now live in a clean and sanitary environment. Human, animal, and poultry waste, as well as daily waste water, are treated by the biogas digesters. Fermentation eliminates 99.9 per cent of the colon bacillus and over 99 per cent of the parasites and their eggs. The widespread use of biogas digesters has reduced the number of breeding places for flies and mosquitoes, thus, drastically reducing the incidence of snail fever, gastric and intestinal disease, and parasitic and other diseases transmitted through mosquitoes and flies. Biogas sludge and slurry are quality fertilizers and feeds. In villages lacking electricity, biogas lamps provide light in which children can study and women have longer hours during which to pursue such economic activities as sewing and embroidering.

In some communities, when biogas construction is completed, a great celebration ensues. Although it costs several hundred yuan to build a digester, farm households are delighted to be able to cook without fuelwood, to have light without oil, and to have bumper harvests by applying biogas fertilizer.

Small Hydropower

Electricity is essential to further economic development in China. With plentiful water resources and high mountains, the theoretical reserve is 680 gigawatts (GW), of which only 300 GW can be exploited. Of this, 75 GW represent small hydropower (that is, having a capacity of less than 25,000 kW).

At the end of 1993, the installed capacity of small hydropower generators was 15 GW, producing approximately 47 terawatt hours (TWh) annually (see Figure 7.3). In over 700 counties in China, electricity supply is based on small-hydropower stations; over 300 counties have realized at least initial electrification through small hydropower (i.e., average per capita electricity consumption is over 200 kWh and domestic electricity consumption is over 200 kWh per farm household).

The construction of preliminary electrification using water resources had additional benefits: it promoted rural development, raised living standards in local communities, improved material and cultural life, developed small-scale industries in the towns, saved fuelwood, and protected the ecological environment.

Figure 7.3 - Small Hydropower, 1985-93

In recent years, micro-hydropower generators have also become popular in China's rural areas. Micro-hydropower stations have an installed capacity of 100 to 10,000 watts. They use small rivers in the high mountains and gorges, and are able to generate electricity with only one to three metres' drop. They can supply electricity to one or several families. At this time, more than 60,000 such generators supply 120 million kWh annually.

Over 10 million households in rural areas across the country use electricity for cooking, thus, reducing the burden on women.

Solar Energy

Solar energy is an important source of "clean energy." China, with its vast expanse of territory, has excellent potential for developing and utilizing solar energy In recent years, the amount of heat and light derived from solar energy has increased rapidly. Solar energy is used in solar cookers, solar water heaters, passive solar houses, middle and primary school buildings, plastic sheet mulch planting, plastic sheet vegetable sheds, and solar animal and poultry pens (see Figure 7.4).

Solar stoves, which were developed in the early 1980s, now number 140,000, primarily in Gansu, Tibet, and Hebei. These areas are rich in solar energy and lack other energy resources. In Tibet, for example, herdsmen who once cooked with fuelwood had to turn to cattle dung when forest growth proved too slow to keep up with demand. In areas with dense population, however, even dung became difficult to obtain. When the State Council implemented the "Sunlight Plan" promoting solar stoves in Tibet, it was well received. In 1992, solar stoves were used by 17,000 Tibetan households in Lhasa and two other areas. By end 1994, after implementation of the Sunlight Plan, these same areas had more than 40,000 solar cookers, with more than 10 per cent of the total households owning them. The dissemination 2.29 million m2 of solar water heaters across the country has helped to alleviate shortages of household energy for bathing and other purposes.

Passive solar houses and buildings for residents and primary and middle schools have spread rapidly in recent years. In the northern part of China, which is rich in solar energy, farmers planning to build new homes prefer solar houses, even though the cost is 20 to 30 per cent higher. Solar houses are clean, hygienic, and warm, and farmers can choose from a selection of standard designs. Solar school buildings provide an excellent study environment. In Liaoning province, where the outside temperature can reach 20 degrees below 0 degrees Centigrade, the temperature in solar school buildings stays at a comfortable 10 to 15 degrees Centigrade. Even on holidays, teachers and students are happy to work and study in the buildings.

Figure 7.4 - Solar Energy Utilization, 1985-93

Large-Scale Development of Fuelwood Forests

China is poor in forest resources. It has only 0.13 hectares of forested area per capita and only 9.3 m3 of forest stock per capita, less than one tenth those of the United States. In the extensive mountain and semi-mountainous areas, the Chinese government has undertaken a policy of promoting reforestation, assigning hillside to farm households that could harvest fuelwood if they plant and take care of trees on those plots. The government describes it as a policy of promoting fuelwood forests by letting "those who plant the trees have them." The forestry departments select high-quality domestic and foreign fuelwood tree seed suitable for growing in different areas; it promotes close planting and rotation cutting, thus, increasing yields two to three times.

Some tree varieties provide additional high-value by-products such as aromatic oil, feeds, protein, and tannin extract. Establishing forests not only alleviates the shortage of fuel-wood, but also increases farmers' incomes. By end 1993, 6 million hectares of fuelwood had been planted (see Figure 7.5).

Figure 7.5 - Fuelwood Forests, 1980-93

Wind Energy

China has a long history of developing and utilizing wind energy. The famous Huanghe windmill in Lanzhou, Gansu, was first built over a thousand years ago. China has a relatively low level of potential wind energy resources.

Large and medium-sized windpower plants can be built in a few places. Xinjiang, Inner Mongolia, and the islands along the southeast coast are suitable for large windpower generators. In these areas, 15 large-sized windpower generators have a total installed capacity of 15,000 kW. But in most areas of the country, small-sized windpower generators are more appropriate. In 1993, China had 119,000 small-sized windpower generators, with a total installed capacity of 17,000 kW. (see Figure 7.6). Together, these generators produce approximately 37 million kWh annually. In Hebei and along the coastal areas of Jiangsu, for example, 1,500 windpowered water lifters irrigate and desalinate farmland.

Figure 7.6 - Extension of Small-Sized Windpower Generators, 1985-93

Geothermal Energy

Geothermal energy refers to heat energy produced from the interior of the earth. Usually the temperature of the water in geothermal wells and springs is about 20 to 60 degrees centigrade. It is suitable for use in aquaculture, crop breeding, hatcheries, and greenhouses. Geothermal energy is used in 860 places around the country, providing energy to 1,400 hectares of cropland and 930 hectares of aquaculture.


China has pursued an integrated rural energy development strategy, focusing on renewable sources of energy, and following a careful approach of scientific experimentation, trial demonstrations, and continuing evaluation. It has taken the county as the basic unit, and simultaneously achieved coordinated development and widespread improvements in the rural economy and in environmental quality.

As the market economy evolves in China, the shortage of energy involves not only shortages in fuelwood for household use, but shortages in commercial energy as well. Energy is needed for development of the rural economy, for industrial development in towns, and to meet the growing energy demands of 900 million farmers increasing their standard of living. Toward this end, a comprehensive programme of rural development has been pursued, involving coordination among various departments and scientific and research units. Emphasis is given to developing local energy sources, improving efficiency of commercial energy, and making energy sources mutually complementary and coordinated.

To date, more than a hundred counties have carried out programmes of integrated rural development; they have succeeded in increasing energy capacity and in providing improved economic, environmental, and social benefits. This, in turn, has helped to reduce women's heavy household burden, improve the living environment, expand employment opportunities, increase incomes, raise living standards, protect the environment, and promote health. It is widely praised by women as "the second liberation of women."


1 Deng Keyun is Deputy Director, Department of Environmental Protection and Energy, Beijing, China.

8. Community Biogas Plants Supply Rural Energy and Water: The Pura Village Case Study


Rural energy planning requires choices among energy technologies. Until recently, the choices have been confined to centralized energy supply technologies - power plants based on hydroelectricity, coal, oil, or natural gas. Increasingly, however, centralized energy sources face two major - and probably insurmountable - difficulties: a) shortages of capital, and b) public opposition focused on local and global environmental degradation. It has, therefore, become essential to extend the list of technological alternatives for energy decision-making to include decentralized sources of supply.2

Potentially, one of the most useful decentralized sources of energy supply is biogas3 - an approximately 60:40 mixture of methane (CH4) and carbon dioxide (CO2) - produced by anaerobically fermenting cellulosic biomass materials. Biogas can be utilized to fuel engines that, in turn, drive generator sets to generate electricity. It has a calorific value of 23 MJ/m3.

Developing-country rural areas have a variety of available biomass materials, including fuelwood, agricultural wastes, and animal wastes. In particular, many countries have large cattle and buffalo herds, whose considerable wastes have much energy potential. Traditionally, these wastes are carefully collected in India and used as fertilizer, except in places where villagers are forced by the scarcity of fuelwood to bum dung-cakes as cooking fuel. Since biogas plants yield sludge fertilizer, the biogas fuel and/or electricity generated is a valuable additional bonus. It is this bonus output that has motivated the large biogas programmes in a number of developing countries, particularly India and China.4

Virtually all biogas programmes are based on family-size biogas plants rather than community biogas plants. Yet family-size biogas plants lose significant economies of scale. The amount of biogas they are able to produce is more suited for cooking than for running an engine and generating electricity.5 Community biogas plants are more economical; the problems associated with them tend to be social rather than technical.6 They may, for example, bring in their wake serious organizational difficulties and possibly equity issues. In addition, the low body weight of free-grazing bovine animals, particularly in drought-prone areas, can make the bovine waste resource inadequate to meet cooking energy needs even when the bovine-human population ratio may seem satisfactory. In such situations, the use of community biogas plants to generate electricity is worth considering, particularly because it is an ideal fuel to run an engine that can then drive a generator and generate electricity. It is particularly useful in the context of dual fuel (diesel and biogas) engines.7

It was against this background that a decentralized biogas electricity system was established and demonstrated at Pura Village (Kunigal Taluk, Tumkur District, Kamataka State, South India) as an alternative for providing rural electricity. Since September 1987, the traditional system (Figure 8.1) of obtaining water, illumination, and fertilizer in Pura Village has been replaced with a community biogas-plant electricity-generation system. This new system consists of the following activities (Figure 8.2):

· Pura's households deliver cattle dung to the biogas plant in the mornings (24 per cent of the dung is delivered by women, 27 per cent by girls, 27 per cent by boys, and 22 per cent by men);

· The dung delivered is weighed and recorded in the owner's passbooks and the plant's ledger books;

· Processed sludge is returned to those who want to withdraw sludge;

· The dung is mixed with water in a 1:1 ratio (by volume) and the biogas plant is charged by the dung-water mixture;

· The resulting slurry is poured onto the sand-bed filters for filtration and production of de-watered sludge;

· Biogas is released from the plant and fed to the engine, along with the requisite amount of diesel, in order to start the dual-fuel engine and the electrical generator;

· Electricity is supplied for illumination of homes and for running the submersible pump that will bring borewell water to the overhead tank;

· The biogas plants and their surroundings must be kept clean;

· The households must be visited to receive payment for electricity services and to make payments for the dung received;

· Plant records and accounts must be maintained.

Apart from the delivery of dung to the plant and the withdrawal of sludge, which are performed by the households, all activities associated with the operation of the biogas plant, electricity generation and distribution, and water supply are performed by two village youth, who have been employed by the project.

Figure 8.1 - Traditional System of Obtaining Water, Light and Fertilizer

Figure 8.2 - The Existing Community Biogas Plant Systems at Pura

Impact of the Biogas System

When the community biogas-plant electricity-generation system was introduced, the village of Pura had already been electrified by the Karnataka Electricity Board grid. But in India, the mere fact that a village is electrified does not mean that individual homes within that village have electricity. In general, only 20 to 30 per cent of the homes are electrified in electrified villages, but in Pura, 43 per cent of the homes were electrified before the new system was installed. By July 1994, 59 per cent of homes had grid electricity, with some having both grid and biogas; the remaining 41 per cent (36 homes) all had biogas electricity (see Table 8.1 for some basic statistics on Pura Village in 1987, 1991, and 1994).

Even the steps toward limited grid electrification that took place in Pura may soon not be possible in other villages. This is true for a number of reasons:

· electricity has become scarce and expensive in India;

· apart from the recent efforts to provide electricity to irrigation pumpsets, rural areas have been neglected in conventional electricity planning, e.g., in Karnataka state, only 20 per cent of the total electricity flows to rural areas;8

· the situation is aggravated by the fact that there are enormous costs and losses involved in transmission and distribution lines (e.g., transmission and distribution losses are about 21,5 per cent in Karnataka);

· electricity has become extremely unreliable in rural areas, both with regard to duration (there is frequent load-shedding) and voltage; and

· even in electrified villages, it is not accessible to most of the people.

As grid electricity becomes scarcer, the need for biogas plants becomes even greater. The remainder of this paper deals with the technical, economic, and managerial aspects of the community biogas-plant system. The future of such systems is dealt with in other writings.9

Table 8.1 - Basic Statistics on Pura Village

July, 1987







Cattle population




Human/cattle ratio




No. of Households




Households with grid electricity









Households with grid + biogas electricity







Households with only biogas electricity







Households with private watertaps








Water consumption (litre/cap/day)



The Technical Subsystems of the Pura Biogas-Plant System

The community biogas-plant system of Pura consists of the following subsystems:

a) biogas plants in which bovine waste is anaerobically fermented to yield biogas,

b) a sand-bed filtration subsystem to filter the biogas plant slurry output and deliver filtered sludge with approximately the same moisture content as dung,

c) the electricity generation subsystem,

d) the electricity distribution subsystem for the electrical illumination of homes,

e) the water supply subsystem.


In order to digest industrial effluents and other wastes with low concentrations of total solids (less than about 3 per cent), a number of advanced designs have recently been developed in industrialized countries.10 These include anaerobic filters, anaerobic baffler reactors (ABRs), anaerobic contact digesters, and upflow anaerobic sludge blankets (UASBs).

However, these advanced designs were not exploited in Pura, which instead utilizes digesters that can handle the type of high-solids-content wastes found in typical village situations, that is, highly concentrated bovine dung, other animal wastes, and agro-wastes.11 The two most popular conventional digesters for this type of waste available in developing countries are: a) the Indian floating-drum biogas plant,12 and b) the Chinese fixed-dome biogas plant.

In the Indian design, an inverted drum with a diametre slightly less than that of the cylindrical digestion pit (usually, but not necessarily, below ground level) serves as a gas holder and provides the anaerobic "seal" while floating up and down depending upon the amount of biogas stored. Such a plant delivers gas at uniform pressure, provides a good seal against gas leakage, is highly reliable and robust, and has a proven performance for bovine dung digestion. Its drawback is that the gas holder is usually made of steel or ferrocement and is, therefore, comparatively costly in addition to requiring regular maintenance.

The Chinese fixed-dome type biogas plant can be constructed locally with standard building materials, such as cement. It is relatively cheaper because it is less materials-intensive. On the other hand, it is skill-intensive and is prone to gas leaks (despite epoxide coatings of mortar on the inside surface) if the construction is not of high quality.

A plug-flow biogas reactor is useful for high volumes of gas production rates relative to typical fixed-dome and floating-drum plants. Its construction is similar to these two types of plants or a combination of both; however, to ensure true plug-flow conditions, the length has to be considerably greater than the width and depth. Although plug-flow biogas reactors may turn out to be appropriate to developing countries because of their low capital cost, they are still in the initial stages of dissemination in these countries.13 Plug-flow reactors may not display special advantages in the case of the digestion of bovine dung, but they permit continuous gas production from bio-mass sources that tend to float, for example, water hyacinth and other aquatic weeds.

Figure 8.3 - Sectional Elevation of the Biogas Plant at Para

The Pura system used Indian floating-drum biogas digesters modified to reflect the cost minimization theory developed earlier14 and realistic residence times based on observations under similar conditions. The dimensions of each digester in Pura are 4.1 m diametre and 4.2 m depth. In addition, the system used low-cost construction techniques (Figure 8.3).15 This modified design has the following salient features:

· The ratio of gas produced per unit volume of the digester is as high as in plug-flow reactors, i.e., 0.5 compared to 0.2 to 0.3 in conventional fixed-dome and floating-drum plants.

· The biogas plants perform better than the original Indian-design plants, i.e., they produce 14 per cent more biogas at ambient temperature in spite of the 40 per cent reduction in digester volume.

· The plants are shallower and wider compared to conventional Indian-design plants, thereby accelerating the rate of gas release from the production zone to the gas holder; hence, the modified plants are easier to construct wherever the ground-water table is high.

· The Pura plants are as much as 40 per cent cheaper than conventional Indian-design plants.

In order to increase the reliability of the system, two plants (each with half the rated gas production capacity) with a common inlet tank were constructed instead of a single plant.

The maximum input to the two biogas plants combined is 1.25 tons of cattle dung per day mixed with 1.25 cubic metres of water per day At this maximum loading, the influent slurry mixture contains 212 kg dry matter (8.5 per cent) having a volatile matter of 177 kg (7 per cent). The carbon content of this mixture is 57 kg (27 per cent of dry matter); the nitrogen content, about 3.6 kg (1.7 per cent); and the carbon to nitrogen ratio, 16.

At an average ambient temperature of 25-26° Celsius, the plants can produce a maximum of 42.5 cubic metres of biogas per day, having a composition that is approximately 60 per cent methane (CH4) and 40 per cent carbon dioxide (CO2). In addition to the gas, the charging of the combined dung and water slurry would displace about 2.45 cubic metres per day of digested slurry; after filtration of the water, this yields about 1.2 tons of sludge per day. This sludge contains 164 kg (6.67 per cent) dry matter having 109 kg of volatile matter, 39 kg carbon, and 3.6 kg nitrogen, i.e., the same amount of nitrogen as in the input. Hence, the carbon to nitrogen ratio is 11.

Human Waste as an Input. Unlike China, India does not have a tradition of using human excrement directly on the fields as a fertilizer. Thus, the community biogas plant in Pura does not use human excrement as an input.

Direct use of human waste material is frequently associated with the risk of spreading intestinal parasites and other pathogens. Chinese biogas plants largely eliminated this risk because their settling chambers at the bottom have long detention times (about six months), which destroys more than 90 per cent of intestinal parasites and other pathogens. Thus, in China, biogas plants perform an important environmental (sanitary) function.

However, Indian biogas plants have short detention times. These are unlikely to destroy intestinal parasites, which are widely prevalent in rural areas of India. As a result, if the biogas sludge were used as a fertilizer, it would likely increase the spread of intestinal diseases. Moreover, since it is not the tradition in India to use human waste as a fertilizer, the "contamination" of the sludge with human waste would have created resistance to acceptance of the sludge fertilizer.

Sludge Fertilizer From Biogas Plants. Since nitrogen does not volatilize during anaerobic digestion, the effluent sludge displaced from the biogas plant contains the same mass of nitrogen as the input slurry. However, the nitrogen increases as a percentage of total solids (since the percentage of total solids decreases from 8.6 per cent to 6.67 per cent); furthermore, the nitrogen is converted into a form that is more available (readily usable) to plants. Hence, biogas plants are often called bio-fertilizer plants.

In fact, anaerobically digested biogas sludge has a higher nitrogen content than farmyard manure obtained by composting bovine dung. The explanation for this difference lies in the traditional practice of putting bovine dung into open-air compost pits before transferring it as farmyard manure to the fields; because of the aerobic decomposition that takes place in open air, the nitrogen in farmyard manure decreases from an initial value of 1.7 per cent on a dry weight basis to a constant value of 0.9 per cent in about ten days. In contrast, the nitrogen content of biogas plant sludge decreases from an initial value of 2.2 per cent to a constant value of 1.9 per cent in about three days in open air.16 Thus, biogas sludge (with 1.9 per cent nitrogen) stabilizes with double the nitrogen content of farmyard manure (0.9 per cent nitrogen after aerobic decomposition). The greater nitrogen content of biogas sludge relative to farmyard manure implies a saving of energy that would, otherwise, have to be used to manufacture an equivalent amount of nitrogen in the form of artificial fertilizer.

Based on their seven years of experience, the farmers of Pura assert that weed growth is far less with biogas sludge fertilizer; they, therefore, use it for premium purposes such as raising nurseries. Whereas farmyard manure "sows" the seeds of the weeds that are ingested by bovine animals and passed through their digestive systems into their dung, the biogas plant either destroys these seeds or makes them less fertile through anaerobic digestion.

The anaerobic process of digesting cattle dung also has an environmental protection function. Unlike cattle dung undergoing aerobic decomposition, biogas sludge does not smell or attract flies and mosquitoes. The people of Pura even say that biogas sludge repels termites, in contrast to raw dung (farmyard manure), which attracts termites that harm the plants. For this same reason, they prefer digested slurry to fresh dung for plastering their threshing yards.


These multiple benefits make sludge fertilizer a particularly attractive part of community biogas plant systems. The households in Pura refused to sell the dung to the biogas plant; they agreed to "loan" it to the plant so that it can be used for anaerobic digestion, but insisted that the sludge be returned to them on a pro-rata basis. The dung, which has 17 per cent solids, is charged into the plants after being mixed with an equal amount of water. The resulting digested slurry is a diluted effluent, with about 6.5 per cent solids. This watery effluent was unacceptable to the villagers because they could not transport it back to their homes.

Separating the solids and liquid in the slurry effluent is not possible with sewage-type sludge sand-bed dryers. Thus, it was necessary, for a number of reasons, to develop a filtration system for biogas plant effluent:

· to facilitate transportation of digested sludge from the biogas plant back to the homes and compost pits,

· to mix the filtrate, which contains some anaerobic microorganisms,17 with the input dung, thereby enhancing gas production marginally, and therefore

· to reduce the water requirement for charging biogas plants.

To meet these needs, a simple, but effective sand-bed filtration system, was developed for filtering digested slurry. The 11 filters constructed at Pura Village together can handle as much as 1.7 cubic metres of slurry per day. Each filter of 4 square metres (4 m × 1 m) consists of three layers: 5 centimetres of gravel at the bottom, then 3 centimetres of sand, topped by wire mesh. Digested slurry effluent is poured to a height of 10 centimetres above the wire mesh.

About one square metre of filter is required for every 100 litres of the digested slurry effluent. The maximum amount of time for filtration varies with the season, but is about 72 hours in the rainy season and about 60 hours in the summer. Thus, to ensure a steady-state operation, a three square metre area is required for 100 litres of slurry effluent. The maximum recovery of water from the filter is about 70 per cent.

The lifespan of the sand beds is about a year. After that, the sand layer has to be completely removed and relaid, and the gravel and water outlet pipes have to be cleaned and relaid. The lining material, which consists of low-density poly-ethylene (LDPE) sheet, has to be repaired or sometimes replaced.

Two village youths are entirely responsible for day-to-day maintenance and operation as well as routine cleaning and upkeep of the filters. They have innovated a simple technique to prevent the dried sludge from clogging the wire mesh - they spread a thin film of wet sand over the wire mesh before spreading the slurry to facilitate easy separation of the dried slurry cake from the wire mesh.

After sand-bed filtration, the slurry displaced from the digester by the daily charging of dung-water mixture contains 17 per cent total solids (TS), i.e., the filtration takes produce filtered sludge that resembles cattle dung with 18 per cent TS. At this stage, it would have been possible to return filtered sludge to the villagers at the rate of 750 grams per kilogram of dung received. But because of the villagers' understanding of the whole biogas process and their confidence in the distribution system, they do not withdraw the sludge as and when it is ready after sand-bed filtration. Rather, they use the biogas system as a "sludge bank" and allow considerable time to elapse between the time the sludge is ready for return and the time it is withdrawn. During this period, there is further decrease in moisture content and an increase in total solids. Thus, it has become the accepted practice to return filtered and dried sludge at the rate of 600 grams for a kilogram of dung delivered to the biogas plant.


A 7 horsepower water-cooled biogas-diesel (dual-fuel) engine has been installed in a small engine room located next to the fields at the edge of the village. The engine has been mounted on anti-vibration footings and bolted firmly to the ground with foundation bolts. The exhaust pipe, attached to a residential type silencer, has been extended through the engine room wall to the open air pointed toward the fields and away from the village. Thus, the engine is hardly audible in the village.

The biogas from the biogas plants passes through a condensation trap and then enters the engine, where it is mixed with diesel to provide the fuel. The engine is coupled to a generator that can operate a submersible pump (a 5 kVA 440 V. 3-phase generator).


The lighting system was energized on October 2, 1988.18 In 1994, it consisted of 91 fluorescent tubelights of 20 watts each - 85 in homes, 2 at a public temple, and 4 in the biogas plant complex. Homes have chosen varying levels of light; 46 households have 1 tubelight, 18 have 2, and 1 has 3. (In addition, since 1993, Pura has supplied electricity for 17 tubelights in the 13 homes of a neighbouring housing colony situated about a kilometre from the center of the village.) The load is distributed equally over three phases, with 36 tubelights in each phase. The low power factor of 0.43 of the tubelight system (consisting of the fluorescent lamp and the choke) has been improved to 0.72 by connecting each tubelight with a 4 microfarad capacitor in parallel; as a result, the power consumption for each tubelight decreased from 31 watt to 27 watt.


The water supply system has been in operation since September 1987. It consists of a 3-phase, 3 HP submersible pump that generates 6.75 cubic metres of water per hour. The pump is fitted into a bore well and lifts water from a 50-metre depth to an overhead tank. The water is then distributed by gravity through nine street taps located at various sites around the village. The villagers themselves decided the location of the taps; one of the taps is for livestock and one tap is in the biogas plant compound. In addition, since September 1990, there has been growing demand for private water tap connections, and there are now 75 private taps inside households. That is, 85 per cent of households have private water tap connections.

A 1977 study of the traditional system of water collection for domestic purposes showed that, on an average, a family used to make two trips per day, taking 1.5 hrs (45 minutes per trip) to cover 1.6 kilometres, to transport 104 litres (4 potfuls) of water; this yielded a per capita consumption of water for domestic purposes of 17 litres per day.19 Another survey in September 1987 showed that water consumption had not changed to any significant extent. However, between September 1987 and September 1988, when a 24-hour supply of piped water became available through public taps, per capita consumption jumped immediately to 22 litres and then slowly stabilized at 26 litres. After the villagers took over the management of the community biogas plant system, they imposed restricted timings for water supply (three times in a day) and the consumption came down to 22 litres between October 1988 and August 1990. The 5-litre increase between 17 and 22 litres is partly attributable to the fact that the bovines are allowed to drink the piped water.


Biogas plants are normally designed on the basis of either the minimum dung available or the maximum gas consumption that is required. Gas production depends upon the amount of cattle dung and the ambient temperature.20 This temperature dependence is the reason for the universal complaint that biogas plants produce very little gas in winter and other fuels are necessary to supplement biogas. But, at Pura Village, for the last nine years, the gas production has been virtually uniform throughout the year. In fact, if there is any reduced output, it is in summer, not in winter.

The amount of dung available to the biogas plant depends upon the number of bovine animals and the fodder intake of these animals. In the case of free-grazing bovines, their fodder intake depends upon the grass cover in the pasture lands, which, in turn, depends upon the rainfall, which is seasonal.

The dung yield varies by a factor of two between the seasons, which means that the loading rate (that is, digester volume × total solids concentration) also varies. The ambient temperature also has seasonal variations. Interestingly and fortunately, the shifts from minimum to maximum and vice-versa in both dung yield and ambient temperature are gradual (not sudden), and the peak of dung yield (loading rate) coincides with minimum temperature and vice versa, i.e., in summer, the temperature is highest, but the dung yield (loading rate) is lowest, and in winter, the temperature is lowest, but the dung yield is highest. Earlier findings have emphasized that the response of biogas plants to these variations in loading rates, ambient temperature, etc., is slow and gradual.21

The other important process parametre, i.e., pH, is uniform throughout the year. The dung loaded through higher loading rates in winter stays for a long time in the digester due to lower loading rates in summer and contributes to gas production even in the summer. Hence, the bigger the biogas plant, the slower the response and the more uniform the gas production. The gas yield (gas/unit weight of input) also increases with the size, diametre, and depth of the plant." At locations where, despite the economies of scale in biogas plant costs, the cost of the plant is not as important as the availability of dung, long residence times of even up to a year can be recommended.

These findings are relevant to the future design of cattle dung plants in South India. It has turned out, quite surprisingly, that the dung available for loading the biogas plant/cattle/day at a particular place in the summer is the most important parametre for plant designers.


The biogas plants require periodic maintenance to keep functioning properly. For example, the gas holders must be painted once every two years with chlorinated rubber black paint to prevent corrosion. The material was designed to be rust free (that is, it was primed with a non-corrosive primer followed by two coats of chlorinated rubber paint). Nevertheless, despite corrosion-prevention measures, after five years of operation, corrosion was observed at the joint, where side sheet and top sheet are welded.

In addition, sand and mud tend to settle at the bottom of the digester in spite of efforts to keep the charge free of sand. When the plant was renovated after four years of operation - following a temporary suspension - the plants were found to have about 0.3 metre of accumulated sand and mud that had to be removed.

The electricity generation sub-system is maintained by the same two village youths responsible for operating and maintaining the biogas plants and the electricity and water sub-systems. An evaluation of maintenance during the first 44 months (4,521 hours), that is, the period from September 1987 to April 1991, found the following:

1. The engine-generator set required no major repairs. In the case of the engine, the fuel injection nozzle was cleaned once and replaced once, and the filter was changed once. In the case of the generator, the rectifier, carbon brushes, and field coil each were replaced once.

2. The minor repairs were mainly in connection with the engine accessories, viz., foundation bolts, radiator, silencer, etc.

3. The daily operation and maintenance activities of the operators have been made simple and routine by means of a flow chart and a problems-causes-remedies chart.

4. In addition, the operators carry out preventive engine maintenance and minor repairs after every 50, 200, 500, and 800 hours of engine operation.

5. The system has contributed significantly to the village by providing training and skills to the operators and increasing the technical awareness of the villagers.

6. Unlike pure diesel, biogas bums clean and, therefore, causes little or no pollution.

7. The dual-fuel engine proved to be reliable for biogas electricity generation systems.

Administration, Organization, and Institution-Building

For community technologies to work, they require proper administrative arrangements, first creating organizations and then building them into appropriate and sustainable institutions.

The key administrative arrangement contributing to success in the Pura biogas electricity generation scheme was payment of a dung delivery fee that went primarily to women. This ensured the involvement of the village women, who are the principal beneficiaries of the water supply and the electric lights.

In terms of organization, the key measure was the establishment of the Village Committee consisting of those who are leaders in traditional community activities such as conducting festivals and dramas. This committee was responsible for overseeing the maintenance and operation of the rural energy center, the contribution of dung, the collection of payments for the supply of biogas outputs (e.g., electric lights and water) to the home, and the formulation and execution of plans for the further development of the rural energy center. The Village Committee achieved a 93 per cent collection of dues from November 1988 to April 1991 - an outstanding performance compared to the dismal record of the large electric utilities in the states of India.

The Pura Community Biogas Plant is held together and sustained by the convergence of individual and collective interests. It is customary to discuss the problem of individual gain versus community interests in terms of the famous "Tragedy of the Commons"23 - the personal benefits that each individual/household derives from promoting the further destruction of the commons (i.e., community resource) are larger and more immediate than the personal loss from the marginal, slow, and long-term destruction of the commons. Hence, each individual/household chooses to derive the immediate personal benefit rather than forgo it and save the commons.

Experience with the factors holding together and sustaining the Pura Community Biogas Plant system appears, however, to illustrate a converse principle that may be termed the "Blessing of the Commons"24 - the price for not preserving the commons far outweighs whatever benefits there might be in ignoring the collective interest. In other words, the "Blessing of the Commons" is based on the coincidence of self-interest and collective interest. Thus, in the case of Pura, non-cooperation with the community biogas plant results in a heavy individual price (access to water and light is cut off by the village), and this is too great a personal loss to compensate for the minor advantage of non-cooperation with the community and non-contribution to collective interests.

There must have been many examples of the "Blessing of the Commons" that contributed to the survival of Indian villages for centuries in spite of the centripetal forces tearing them apart. Among those examples must have been the maintenance of village tanks, common lands, woodlots, etc. It is important to discover and utilize such examples for the design of rural development projects in general, and rural energy centers in particular. It is important to use the principle of the "Blessing of the Commons" as a heuristic device for designing rural energy centers. Since it subjects individual initiative to local community control, it is a distinct alternative to the privatization (deregulation) option being offered as a solution to the defects of state control and regulation of the commons.


1 Amulya K.N. Reddy is President of the International Energy Initiative, Bangalore, India. P. Rajabapaiah is Technical Officer, and H.I. Somasekhar is Senior Scientific Assistant, of the Centre for the Application of Science and Technology to Rural Areas (ASTRA), Indian Institute of Science, Bangalore India.

This chapter is based on a paper prepared for the workshop on Biogas Technology for China, at the China Center of Rural Energy Research and Training, Beijing, November 2994. The workshop was organized by the Department of Environmental Protection and Energy, Ministry of Agriculture, Beijing, and the Working Group on Energy Strategies and Technologies of the China Council for International Cooperation on Environment and Development.

2 In fact, it has become essential not to limit planning only to supply options, but to extend the list of alternatives for energy decision-making to include energy efficiency improvement and other conservation options. These options of energy saving are outside the scope of this paper. They are, however, dealt with in Reddy, Sumithra, P. Balachandra, and A. D'Sa, "Comparative Costs of Electricity Conservation and Centralized and Decentralized Electricity Generation," Economic and Political Weekly, June 2, 1990, pp. 1201-1216.

3 K.C. Khandelwal and S.S. Mahdi, Biogas Technology - A Practical Handbook (New Delhi: Tata-McGraw-Hill Publishing Company Limited, 1986).

4 Biogas in Asia and the Pacific, Report of the Regional Expert Consultation on Biogas Network, October 28 - November 1, 1986, Bangkok, Thailand; A Chinese Biogas Manual, translated from Chinese by Michael Crook and edited by Ariane van Buren (London: Intermediate Technology Publications, Ltd., 1979); Diffusion of Biomass Energy Technologies in Developing Countries (Washington: National Academy Press, 1982); and R.C. Sekhar and C. Balaji The Biogas Programme for Rural Development: Some field Based Reflections (Anand, India: Institute of Rural Management, March 1989).

5 J. Goldemberg, T.B. Johansson, A.K.N. Reddy, and R.H. Williams, Energy for a Sustainable World (New Delhi: Wiley-Eastern Limited, New Delhi, 1988).

6 M. Maniates, "Community Biogas Plants: Social Catalyst or Technical Fix?" Soft Energy Notes, Vol. 6, No, 2 (1983).

7 Diesel engines are suitable for this purpose for several reasons: (1) the low flame velocity of biogas is best suited to low-speed diesel engines, (2) they have a high thermal efficiency compared to other type of engines, (3) they are more extensively used in rural areas than other types of engines, (4) the normal working life of a diesel engine (4-8 years) is more than other types of engines, (5) they are reliable and simple to maintain, (6) they can be easily converted to the dual-fuel (biogas-diesel) mode, which is the most practical and efficient method of utilizing biogas, and (7) in case of a shortfall in biogas supply during an important operation, the engine switches over smoothly without interruption to conventional diesel operation. Thus, the use of biogas in biogas-diesel (dual-fuel) engines is ideal for electricity generation in rural areas because it is a clean fuel for combustion in engines with little or no pollution, unlike diesel; it is a locally available and renewable source of energy; it can be produced locally with indigenous technology; it can be produced cheaply; it can provide employment to local people and it makes the rural electricity systems self-reliant.

8 A.K.N. Reddy, Gladys D. Sumithra, P. Balachandra, and Antonette D'Sa, "A Development-Focused End-Use-Oriented Electricity Scenario for Karnataka," Economic and Political Weekly, Vol. 26, No. 14 (April 6,1991), p. 891-910, and No. 15 (April 13, 1991), pp. 983-1001.

9 P. Rajabapaiah, H.I. Somasekhar, and A.K.N. Reddy, Scenarios for the Future of the Pura Community Biogas Plant (in course of publication).

10 H.C. Arora, and Chattopadhya, "Anaerobic Contact Filter Process: A Suitable Method for the Treatment of Vegetable Tanning Effluents," Water Pollution Control (G.B.) 79 (1980), pp. 5-6; A. Grobicki and D.C. Stuckey, "Performance of the Anaerobic Baffled Reactor under Steady-State Shock Loading Conditions," Biotechnology and Bioengineering 37 (1991), pp. 344-55; LA. Roth and C.P. Lentz, "Anaerobic Digestion of Rum Stillage," Canadian Institute of Food Science Technology Journal 10 (1977), pp. 105-8; I.W. Koster and G. Lettinga, "Application of the Upflow Anaerobic Sludge Bed (UASB) Process for Treatment of Complex Wastewaters at Low Temperatures," Biotechnology and Bioengineering 28 (1985), pp. 1411-17.

11 David Stuckey has brought to our attention (personal communication) the fact that ABRs can handle wastes up to 5 per cent total solids in animal manure.

12 The Indian design is also known as the Khadi and Village Industries Commission or KVIC design.

13 According to David Stuckey (personal communication), "there have been full-scale (120 m3) plug-flow reactors for almost twenty years (e.g., at Cornell University in the United States) and the small-scale ones developed in Taiwan have been operating for fifteen years. They are easy to install and operate, and relatively economical, although they have not diffused to a large extent probably because they take up more land area than below-ground units."

14 D.K. Subramanian, P. Rajabapaiah, and A.K.N. Reddy, "Studies in Biogas Technology: Part II - Optimization of Plant Dimensions, Proceedings of the Indian Academy of Sciences C2 (1979), pp. 365-76.

15 The low-cost techniques adopted by ASTRA included the following: (a) based on structural analysis, the minimum thickness used for the 4.2 m high digester wall is just 120 mm, compared to the 360 mm of the conventional digesters; (b) ordinary plastering for the interior of the digester wall (because the dung slurry itself is a good sealant) in contrast to the multi-layer plastering with a coating of leak-proofing compound, and (c) precise excavation to the size of the digester plus walls to enhance the strength of the wall as well as to minimize the refilling and thereby reduce the cost.

16 Unpublished results referred to in P. Rajabapaiah, K.V Ramanaiah, S.R. Mohan, and A.K.N. Reddy, "Studies in Biogas Technology: Part I - Performance of a Conventional Biogas Plant," Proceedings of the Indian Academy of Sciences C2 (1979), pp. 357-64.

17 Unpublished laboratory data of Stuckey (personal communication) suggests that "almost all the anaerobes are attached to the solid lignocellulosic particles, hence recycling liquid saves water, but would not increase cell concentration in the reactor." Chanakya and Ramaswamy (personal communication) have both found anaerobes suspended in the filtrate also, although most of them are attached to the solid particles.

18 October 2 was chosen to inaugurate the illumination of homes because it is celebrated in India as the birth anniversary of Mahatma Gandhi, who urged the country to "wipe every tear from every face." To an implementor of energy plans, Gandhi's call translates to illuminating homes that are an "area of darkness" (the title of VS. Naipaul's novel).

19 ASTRA, "Rural Energy Consumption Patterns: A Field Study," Biomass, Vol. 2, No. 4 (1981), pp. 255-80.

20 The range of temperatures in South Karnataka, where Pura is located is 34.2-20.9°C from March to May, 27.6-20.1°C from June to August, 28.0-18.7°C from September to November, and 29.1-216.1°C from December to February.

21 P. Rajabapaiah, K.V. Ramanaiah, S.R. Mohan, and A.K.N. Reddy, "Studies in Biogas Technology: Part I - Performance of a Conventional Biogas Plant," Proceedings of the Indian Academy of Sciences C2 (1979), pp. 357-64.

22 This observation is applicable to digesters with a depth greater than 0.5 m, i.e., almost all conventional digesters.

23 G. Hardin, "The Tragedy of the Commons," Science 162 (1968), pp. 1243-48.

24 A.K.N. Reddy, "The Blessing of the Commons," presented at the International Conference on Common Property, Collective Action and Ecology, August 1992, Centre for Ecological Sciences, Indian Institute of Science, with support from the Social Science Research Council (New York), the Smithsonian Institution (Washington), and the Ford Foundation (cf. Report by Subir Sinha and Ronald Herring, Economic and Political Weekly, July 3-10, 1993, pp. 1425-32).