In order to know the trend in levels and types of energy consumption at macro level, the energy consumption at state level was studied before taking up village level studies. The source wise energy consumption in Karnataka3 reveals that 53.20% of the total energy is met by non commercial sources of energy like firewood (43.60%), cow dung cake (1.40%) and agrowastes (8.20%). While commercial energy like coal (5.80%), oil (11.60%), kerosene (2.60%), LPG (0.70%) and electricity (26.10%) constitutes 46.80%. A significant part of this non conventional energy sources such as firewood, agriculture residues etc. are to cater the heating (domestic) needs of the rural population (about 70 ‑ 80% of the total) and then followed by village industries.
As a first step to understand rural energy problems, ASTRA (Centre for Application of Science and Technology for Rural Areas) of Indian Institute of Science, Bangalore conducted a detailed survey in six villages in Kunigal taluk (Tumkur District) in Karnataka4 during 1975-76, based on observations discussions, measurements and checks. Some of the findings are: (a) Firewood is a dominant energy source (81.6%), used mainly for household activities, (b) cooking is a major activity consuming human and firewood energy. Efficiencies of chulahs are in the range of 5-8%, (c) human energy (especially women and children) was inefficiently used in firewood gathering (2.6 hrs/day/hh), cooking (3.68 hrs/day/hh), carrying food to farms (1.82 hrs/day/hh), fetching water (1.53 hrs/day/hh), taking cattle for grazing (5.54 hrs/day/hh) etc. The share of domestic burden between men, women and children is 24%, 20% and 20% respectively, (d) kerosene consumption for lighting is about 4.3 litres/un-electrified house, 78% of the houses being unelectrified, and (e) industrial consumption is very small.
Roger Revelle5 estimated the total energy utilized in rural India for the year 1971. As per his study and analysis, only 10 per cent (1.2 x 1014 kcal per year) of the total energy (11.42 x 1014 kcal per year) in rural areas was derived from the commercial sources mainly contributed by kerosene, diesel, chemical fertilizer and electricity from hydro sources. The remaining 90 percent is derived from traditional sources of energy viz. Human and animal labour, firewood, crop residues and animal wastes. Revelle concludes that rural people in India are tied to poverty and misery mainly because they use too little energy and use it quite efficiently, and nearly all he energy they use is secured by their own physical effort. Increasing the quantity and improving the technology of energy use, he suggested, can bring about a transformation of rural India.
Gerald A. Leach6 reviews the major features of residential energy use that have bearing on demand and supply options. Leach also examines the profound changes that have occurred over the past few years in attitudes to wood fuel problems and their implications for energy policies and planning. Data from 15 country assessments show that households account for 30-95% of total energy use, compared to 25-30% for industrialist countries. The highest proportions are found in poorer countries, where households exclusively depend on biomass fuels.
Ramakumar7 gives conceptual model of an Integrated Renewable Energy System for a Village, wherein available biomass sources are converted to biogas to supplement the output of a sub system designed to integrate the solar radiation and wind resources.
A study of 74 Indian Villages8 involving more than 5200 households, found that Village average biomass fuel use of 4-6 GJ per capita annually in 30% of the Villages and 2-8 GJ in 65%, but that the complete range was 1.5-20.5 GJ.
Ved Mitra and Ashwin Kumar9 expressed that global concern regarding deterioration of the environmental conditions is also providing added impetus to the development of energy alternatives in particular renewable sources of energy. The duo emphasizes on the role played by energy in economic and social development in every society.
J. B. Lal10 worked on the survey made by Forest survey of India in the late eighties. His study revealed that India consumes as much as 157 million tones of firewood annually against the sustainable level of production of 58 million tones per annum. The enormous gap between demand and sustainable production of firewood is one of the major causes of depletion of forest resources in the country. He further stresses on the chance of reducing demand by increasing thermal efficiency of firewood burning as a means to conserve forest as well as energy resources.
AFPRO (Action for Food Production)11, an NGO, in collaboration with CHF (Canadian Hunger Foundation) have been involved in promoting biogas in India since 1984. TERI (1997) has worked on how NGOs can help promote renewable energy technologies in Rural India. TERI has documented role of biogas plants in a regional energy situation and importance of monitoring the projects to assess the success rate of the technology and gives way for further improvement in the technology.