|Low Cost Charcoal Gasifiers for Rural Energy Supply (GTZ, 1994, 49 p.)|
|8. Non-technical aspects of gasifier operation in the field|
The intent of the previous chapters was it to demonstrate that it is possible to build a cost-effective and reliable gasifier for charcoal. The basic conditions for a practical application of gasifier-engine-systems in the power range 2 - 10 kW seem to be fulfilled. What else can go wrong? Some comments to nontechnical problems, typical for situations in rural areas of developing countries, may be useful to remind of the complexity of technical co-operation.
The fact that a ferrocement gasifier can be built at any location, using locally available materials and a few simple tools, fits perfectly into a self-help strategy for underprivileged parts of the population. In fact, encouraging proper engagement of the target group of rural development programmes helps to avoid a wide spread "gift mentality" and seems a promising approach. Some pro's and contras with respect to owner-built ferrocement gasifiers will be discussed here.
The way how to manufacture a ferrocement gasifier has so far been documented in the manual of R. Reines  and Alan Gonzales/ Bui Tuyen . These documents are adequate to inform the scientific and technical staff of an institution, that means, to inform the later"multiplicators" of a know-how transfer. But a written manual is not helpful to people with a low educational level. The capability of people in rural areas of developing countries to read and to interprete written instructions and blueprints is very limited.
Making vessels by handling wire and cement seems to be an easy job which can be done by anyone with average skill. Basically this is true, but it should not be forgotten that the typical, interested potential user is an absolute beginner. He has, normally, to learn how to work with wire and cement mortar, but simultaneously he has to get an idea what happens in a gasifier of the type he is just building. This is more complex than it may appear. At the educational level which can be expected in developing countries, a do-ityourself approach can only be realized with the help of well-trained instructors. Patience and care are the most important "skills" which have to be trained with any new group.
It is not only the necessary skill which has to be considered in a do-it-yourself concept. Financial aspects play an equally important role. At first glance, do-it-yourself seems to be by far the cheapest solution to acquire a gasifier. But, it has already been said that the do-it-yourself method depends on well-trained instructors. In rural development projects the salary and the travel expenses of the instructor will normally be covered by governmental institutions or donor agencies. If not, the costs of the instructor are a relevant part of the overall costs.
As soon as a relevant number of gasifiers is to be installed within a certain area (forming a "cluster" of gasifier application sites), a commercialization of the gasifier manufacturing is a recommendable way. The following principle has been tested in Bremen as well as in Argentina [ 1 1]: At the manufacturer's place, all the inner cylinders and attachments are completely prefabricated (see figs. p. 16). These components are transported to the site of installation. At the site, the large cooling tank is built and the final assembly is done with the participation of the later user group. In that way, the construction is done effectively by trained personnel, and the final costs are still low due to the low level of labour costs.
A summary of these considerations is:
- The do-it-yourself method is not always applicable. It is possible that the user of the plant is not interested in investing his own time and prefers to pay for it. This is realistic, considering the low labour costs in developing countries, which make the ferrocement concept so cheap.
- It is possible that manufacturing by the users (a community) is difficult to realize for reasons of insufficient availability of qualified labour.
- For the above reasons, the promotion of local manufacturers of ferrocement gasifiers has to be considered as an alternative or as a supplement to the self-help approach
- On the other hand The self help approach may not be always applicable, but at least this possibility exists. This is not the case with conventional gasifiers, which always require the facilities of a rather well equipped metal workshop. If the participation a of team of community members-preferably the later operator team-can be organized, and if the operation and maintenance of the gasifier is reasonably integrated in the economic activities of a community, the self-help approach is a unique chance to save investment costs, acquire the necessary qualification, and settle responsibility for the equipment.
The existing gasifier programmes are addressed to two typical user configurations: The "community plant" and the "private owner plant". The basic conditions as well as the economic situation of these cases of ownership are remarkably different, and any dissemination strategy has to define exactly which is the target group.
a) The community plant
The most common application (expressed in numbers of installed gasifiers, for example within the gasifier programmes in India and Thailand) is the gasifier with engine and electric generator, installed for village electrification (most of all: light and television). Typical features are:
- The financial power of the community is too low to meet the investment costs (even with a low-cost ferrocement gasifier, the costs for engine, generator and electric grid have to be considered). The installation is highly or completely subsidized by institutions or governmental agencies. This subsidy is seen as part of a compensatory activity to improve living and working conditions in economically underdeveloped regions.
- The operational costs are the salary of the operator and fuel costs. The total of the operational costs is significantly lower than the savings for kerosene and candles, used for lighting purposes before, and the users can enjoy a limited luxury like radio and television at reduced costs (no batteries and no fees for battery charging).
- The community members contribute by "cash or in kind": Typically they pay a small amount of cash and supply a certain amount of the fuel. Due to very limited and irregular income, especially the contribution by cash is irregular. This results in decreasing motivation of the operator, who is not acknowledged adequately for his job.
- As the typical village electrification system does not contribute to an increase of monetary incomes of the community, it is not considered as a first priority asset. A general feeling is that the government, who subsidized the plant, should take care of the operation as well.
The motivation of a community to maintain a gasifier powered electricity supply is very sensitive to fluctuations of the socio-economic situation. According to Jain , the same mechanism is valid in India as observed in Colombia [3, 4]. Electricity for lighting purposes is a unanimous demand, if village communities are asked, but nevertheless it is not a basic need. Faced with the offer to get a subsidized gasification plant, the communities take their chance to get electrification without major financial participation. Seeing this probably unique chance, they agree to take over the operational costs, e.g. the salary of the operator and the costs for fuel preparation. But, if for any reason the financial situation gets worse, the financial contribution for electric light is the first expenditure to be saved, and participation by fuel or labour does not help the operator in his specific situation.
In all reported situations in India, Thailand and Colombia where community electrification was installed by means of a gasifier and where the operation costs were left to the users, problems are reported due to irregular paying of the fees. Internal conflicts of this kind often result in idle periods of the plant and in a change of the responsible operator, when he is not longer willing to do this job. The new operator is less qualified, and further problems in operation and maintenance are to be expected.
A community installation which was fully subsidized and maintained by an institution (Jain), with the users paying only a small symbolic fee, was successful. This indicates again that not technical problems, but user behaviour is the source of trouble.
In the two community installations in Thailand, described as case studies by Naksitte , the participation of the users does not seem to present major problems. The villagers contribute with charcoal as well as with electricity fees. But the positive results in Thailand are perhaps due to the fact that these installations have been installed a few month before the evaluation. During the gasifier project in Colombia, it could be observed that in the first year after installation everything is organized very well, but then, gradually, the conflict begins. These conflicts could be solved, when external advice and technical assistance by regular visits of authorities were available.
Communal electricity supply is obviously an especially difficult application, and it will not develop just by offer and demand of gasifier plants. The typical low-income-community, living mainly by subsistence agriculture, has no real chance to decide which energy plant is the most economic solution for it. The village cannot afford any energy plant. If a governmental agency wants to help this underprivileged part of the population, gasifiers can be the best solution: They are much cheaper than the connection to the public electric grid, and after the installation the system is autonomous in its fuel supply. The hardware costs of the gasifier plants with 3-10 kW electric power output are not a relevant factor for a governmental programm. It is not really a crucial question whether the specific installation costs are US $ 200.-or $ 500.-per installed kW. What makes a dissemination programme of that kind expensive are the salaries of the engaged governmental employees, the travel expenses and the organizational infrastructure.
If serious programmes for development of underprivileged regions exist, much more than energy supply is necessary. If such a programme deals with improvement of agriculture, production of marketable goods, reforestation, communal organization - than it seems to be logical to include the appropriate energy supply, and this can mean gasifiers. In that case, a concentration of gasifiers in "clusters" of approximately 10 villages makes sense. This makes the efficient organization of the fuel supply (commercialisation of charcoal production for the gasifiers) as well as the technical back up much easier.
Even if the installation costs are not the crucial point in that situation, the ferrocement-gasifer appears to be advantageous. If the users participate in the construction, or if a local group specializes in building ferrocement gasifiers, the plants would not be a "gift" from the government. It is very probable that this results in an increase of motivation to maintain the plant, apart from the advantage that any repair of the plant is easy and that the technology of building containers and pipes in cement can be very useful for other applications.
b) The private owner plant
The gasifier run by a private owner or an institution is up to now not so numerous as the community plant, but the percentage of success seems to be much higher, as soon as there is a real economic advantage. According to the case studies in India and Thailand, the typical features are:
- The gasifiers are seen as ´´demonstration units" and installed by scientific institutions, involved in gasification research. The investment costs are subsidized. The owner does not belong to the poorest of the poor: He would be able to finance a plant on its own, but he is not sure yet that a gasifier is technically reliable enough, and that the savings in fuel costs are significant.
- It is easier for the private owner to assess the economical advantage of the gasifier. The more operational hours per year, the higher the savings in fuel costs compared to liquid fuel operation. If only light in the evening is supplied, this is not so interesting in terms of financial benefits, but it may be done as a sort of interesting experiment. If agricultural or other commercial activities are combined with the energy use (irrigation water pumping, flour mill, etc.), the gasifier becomes economically interesting.
- The private owner has a particular interest in the successful operation of the plant, he is usually more qualified than a communal operator and more flexible when repair- or maintenance problems come up. He is really testing the gasifier to see whether it is useful to save money or to give a reliable energy supply. The private owner loses interest, if the technology appears not to be reliable and needs too much care.
Generally, the motivation is much better, if a private owner (or, even better, an owner/ operator) is running the plant. In the examples reported by Jain, the use of private pump sets and electricity supply by small (3.5-7.5 kW) gasifiers was successful, if the location was remote from the electric grid, or when the electric grid was considered as unreliable. Two examples for heat application (institutional cooking) in India show positive results. An installation, run by a well organized institution to supply energy (cooking gas or electricity) to the training centers and the canteen, is more or less equivalent to ´'private ownership": The responsibilities are clear, the salaries of the employees as well, and economic advantages by reduced fuel costs are easy to monitor. It must not be overlooked, however, that CO2 is a poisonous gas, requiring careful handling of the stove.
In the case of the private owner, the investment costs are extremely important. The ferrocement concept can reduce these costs considerably. It is, however, not probable that the typical private owner will have the time and interest to build the gasifier himself. In the majority of cases he considers himself as an entrepreneur whose activities do not allow to spend three weeks in building a gasifier. In that case, a gasifier manufacturer must be able to build the plant on the location, either completely or by using prefabricated components. The typical manufacturer would not be a metal work-shop, but a firm which deals with construction elements and plastering. Such commercial manufacturers of cement gasifiers do not yet exist, and the realistic product costs are not yet verified. First estimations are lined out in chapter 9 of this report.
Of course, a gasifier means always some additional costs compared to the mere combustion engine, and it is important to keep in mind that these additional costs are not only hardware costs but increased labour costs for operation as welt But, if the gasifier is reliable enough-that means that costs and efforts for maintenance and repair are not dominated by the subsystem gasifier, but by the rest of the technical equipment (engine, additional equipment like generator, waterpump, mill etc.) -than it is just an exercise in economic calculation to assess if a gasifier is viable or not. In that case, the dissemination of the gasifier technology can be left to the market situation and depends on the specific fuel costs and the operational hours per year. Pumps sets for irrigation water, flour mills, small machinery in cottage industries are the typical applications. Institutional cooking is an interesting (but dangerous) application. Electric lighting will be more an additional use of an existing plant, but not the driving force to install a gasifier.
Apart from very small plants (2-3 kW electric), even the private owner will not do all the work himself. Commercial units and, of course, the communal plants always are run by an operator, who is responsible for the fuel supply, starting of the plant, maintenance work and repair. The work load of the operator can vary considerably and depends on the size and the reliability of the plant.
A well designed gasifier should not need much care during routine operation: Just to fill in the fuel, ignite it, and- after 10 minutes of primary air supply by ventilation - start the engine. Once a week some cleaning and once a month a checking-that should be enough.
But energy supply and consumption means much more. In fact, especially village electrification is a very complex scheme, with the gasifier, fuel preparation, combustion engine, electric generator, local electric grid, and consumer instruments. Often it is not the gasifier, which causes trouble, but the electric system (generator, cables, insulation, switches, electric equipment) which may have a defect difficult to identify. The more complex the system, the more qualification is needed. A good operator is a real technical expert in his environment and deserves recognition.
A basic technical knowledge of the required level cannot be expected in rural areas where technical infrastructure is virtually absent, it has to be built up with patience. Very often, it is not enough to train the operator in the handling of the gasifier in a training course. In the every-day practice he must know much more, and he is not able to learn it all in just one introductory course. He needs continuous advice for an extended period until he has got the necessary experience. Therefore the introduction of any technical equipment -not only gasifiers-has to be integrated into projects of rural development, where regular visits of the concerned villages are established. This regular backstopping was not always sufficient in the existing projects and the results were rather frequent standstills of the plants until the problem was identified and solved.
Even a high skilled operator is not motivated to care intensively for a gasifier which is obviously badly designed. Especially the skilled operator will be fascinated by a smoothly running plant and will be motivated to keep the system alive, if it is worth the effort. There is no way to deliver a badly designed equipment and hope for skill and motivation.
In common practice, the operator has a lot of responsibility, but usually very little remuneration. It is often assumed that the operation of a gasifier is something which can be done by a member of the community on a more or less voluntary basis. This is not realistic. The qualification and responsibility of the operator deserves adequate financial compensation. Principally, this is accepted by the village communities: They use to collect money for electricity supply. But electric light is not first priority. Light in the houses, radio, television - that makes life more convenient, but is a luxury that costs money. If they are in financial trouble (which happens very often), they don't pay the operator. If they don't pay, the operator is frustrated and will not do his work properly. This results in irregular electricity supply and angry reactions of the users. A conflict is likely.
A resume of the above considerations is:
- From the view of technical performance, the ferrocement gasifier is an adequate option for the supply of mechanical or electrical energy in the 10 kW range. Waterpumping, saw mill and grain mill operation are excellent options. Rural electricity supply is the most complex task. A decision for a particular kind of application has to be based on an adequate level of technical knowledge and skill
- The ferrocement concept offers much better chances for economic viability than traditional gasifiers. But, economic viability depends on local costs of traditional energy, of materials, and of labour. This has to be calculated accordingly.
- Gasifier systems should be used for income-increasing activities Only the perspective of a higher living standard is motivating enough to deal with machinery like a gasifier-engine-systern and the complexity of fuel preparation.
- The operator must be adequately trained and paid.
- Private ownership is more reliable than community plant scheemes The traditional communal organization is -in most cases- not compatible with the sustainable management of technical systems like a gasifier