India, China seek improved efficiency in biogas schemes

One of the salutary results of increased oil prices during the 1970s was a greater interest in nonconventional sources of energy. India and China, both pioneers in production of biomass energy, have accelerated diffusion of biogas digesters in their rural areas to relieve the crisis in cooking energy. In both countries biogas is regarded as a means of ensuring soil renewal, environmental protection, and hygienic cooking.

With a warmer, more stable climate and easy availability of cow dung, India is in a more advantageous position than China for popularizing biogas. However, as a result of different socio-economic systems and approaches to programme administration, China has about 7 million biogas plants covering about 5 per cent of its rural population, while India's 600 000 biogas plants serve less than 2.5 per cent of its total rural population. But India has begun giving impetus to its biogas diffusion programme. According to Vasanth Sathe, India's Energy Minister, over 85 per cent of the Indian biogas plants set up under the National Programme for Biogas Development (NPBD) launched in 1980 are in use, while only about 4.5 million of China's 7 million biogas plants are in a functional state at any given time. Reasons cited by Sathe for the "large-scale failure and disuse of the Chinese biogas plants" were leakage and corrosion, massive temperature fluctuations, lack of a well-oiled machinery to monitor and repair biogas plants, and the latest government policy of promoting high technology ventures in preference to alternative technology systems, such as biogas and bullock carts. Observers speculate that the Chinese biogas programme has been stagnating since 1980.

Chinese biogas plants are much less expensive than their Indian counterparts. A cost-benefit analysis of China's biogas programme shows that for an individual household the investment cost of a family-sized biogas plant is recoverable within a year's time. On the other hand, the Indian biogas digester originally designed and promoted by the Khadi and Village Industries Commission (KVIC) costs around US$650, a sum that only rich farmers owning at least five head of cattle can afford. Moreover, the benefits of biogas technology are indirect, since biogas plants do not bring in cash income. As a result, even with large and generous government subsidies and liberal bank loans, the investment cost is not recoverable in less than four or five years. Chinese biogas digesters of "fixed dome design" are simple to operate and cost the equivalent of $25, or about 15 days' earnings for the average Chinese peasant family.

At present, much of the dung produced by about 260 million head of cattle in India is made into patties and burnt away as wasteful cooking fuel. Assuming an average production of 10 kg of dung per animal per day and a collection rate of 60 per cent, the

amount of dung available in the country in a year works out to 575 million tons, which could generate a staggering 300 million tons of humusrich manure. As it is, 30 million m3 of biogas equals 20 million tons of kerosene oil, nearly three times the annual consumption of the commodity in the country. According to an estimate by the Indian Planning Commission, given the prevailing land distribution and cattle ownership pattern in the country, there is scope for installing as many as 15 million biogas plants.

China has the advantage over India in feedstock for biogas. The Chinese depend mainly on pig and human excreta to feed their biogas plants. Since pig rearing is one of China's most common household economic activities, 70 per cent of the 250 million pigs in China are privately reared. Most rural Chinese households are potential customers for biogas. India, on the other hand, emphasizes cow dung as the feedstock for biogas generation.

In contrast to the egalitarian Chinese approach to the diffusion of biogas to the rural masses, biogas technology in India has failed to reach the rural poor. For biogas technology to be viable, the minimum requirement is four to five head of cattle, but in India only 22 per cent of the 85 million rural household possess five or more head. This makes the administration of dung collection and gas distribution extremely difficult As Professor T. K. Moulik of the Indian Institute of Management, who recently visited China to study the biogas programme there, notes, "Broadly, India's biogas technology development programme can be characterized as te, in both the initiative and participation, while the Chinese process has been largely egalitarian."

Another area of striking difference between India and China is that, in contrast to Chinese farmers, Indian peasants have yet to grasp fully the potential of biogas plants to produce humus-rich fertilizer. Indian planning experts feel that the biogas technology in India is unlikely to make headway unless the rich farmers in India are convinced that the humus-rich manure produced in biogas plants is good for crops and soil.

Though KVIC has been busy popularizing biogas digesters in India since 1950, by the late 1970s there were not more than 100 000 biogas plants in the country. Those who initiated the development of biogas technology in India were concerned more with technological efficiency than with the cost element, construction methodology, or social acceptability. The floating gas holder type of digester promoted by KVIC, though technologically viable, was rejected by India's rural masses because of its cost - $650.

Another important difference is that India's floating dome biogas plant requires about 27 m2 of land for the plant and slurry pit. In most Indian villages, dwellings are so close together that it is rare to find a house-hold with sufficient land for a plant. On the other hand, in Chinese villages, space required for biogas plants have not posed a serious problem.

While in India the biogas programme was imposed from above without active and meaningful participation of the users, the initiative for the Chinese biogas programme came first from the peasants of Sichuan province. The official Chinese policy on biogas encourages initiative and people's participation at all levels. Thanks to this decentralized strategy, biogas diffusion in China has become a people's movement. The strategy has led to the evolution of inexpensive, locally adaptable technology of fixed dome water pressure bioqas digesters. But the stranglehold of centralization and professionalization has been so strong on the Indian biogas programme that not only has the people's participation in me programme been minimal but also research and development efforts have remained confined to laboratories.

The Indian biogas programme has been making rapid strides since NPBD was launched in 1980. During 1984 85 against the target of 150 000 plants, NPBD was able to set up 180 000 units, thus demonstrating the slow but sure acceptance of biogas by Indian villagers. Quoting several independent surveys, official sources say that the failure rate of Indian biogas plants has now dropped to 15 per cent from 40 per cent in the early 1980s.

Taking into account the socioeconomic realities in the rural areas, India has been vigorously developing and promoting a variety of low-cost but technologically efficient models. This multi-model approach seems to be yielding dividends if the latest figures on the spread of biogas plants in India is any indication.

In the final analysis, both the Indian and Chinese biogas plants seem to be moving toward me same goal - large-scale popularization of bio-energy through decentralized, egalitarian strategy and introduction of inexpensive but technologically efficient digesters.

Radhakrishna Rao