Utilizing cow dung and slurry for energy sufficiency of farms and households: Experiences of field studies across three Indian states

Abstract

Studies were undertaken at the appraisal phase (2003), concurrent stage (2005-2010) and terminal phase (2012). At the appraisal stage, PRA exercise was done by a multi-disciplinary team of scientists in the villages of Ureeka and Pipli of Chirawa Tehsil of Jhunjhunu district of Rajasthan; Achhej and Pahripur of Jhajhar district in Haryana and Nekpur , Siriyal, Chak and Jahagirpur of Bulandshahar district in Uttar Pradesh (UP). Data were collected from the above eight (8) villages on longitudinal basis, i.e. during pre-project stage (appraisal stage), ongoing snowballing of the intervention (i.e. concurrent stage) and after the closer of the project (i.e. terminal stage). Data were collected from 250 biogas users on the parameters of most acceptable technical requirements for the unit, output analysis of biogas, use analysis of biogas slurry, economic analysis of the unit, the intangible benefits from biogas and also the constraints experienced therein. These data were collected from individual farmers as well as from their group to arrive at most agreeable information. The simple statistics of average, percentage and unitary derivations were worked out to draw meaningful conclusions. Results indicated that in general farmers across the three states preferred the smaller size (3.0 m3) of the plant which required the lower cow dung quantity (75 kg/day). The cost of construction of thesmaller unit was found to be affordable in three states which ranged from Rupees 14-15 thousand/unit. The quantity of usable quantity of gas produced from the unit ranged from 40-45 kg/month/household. The quantity of gas produced was estimated to be equivalent to three LPG cylinders/household/month which was sufficient for meeting the kitchen and other requirements of the family on daily basis. From the gas produced, every household could utilize the light energy equivalent to 300 watts for 4 hr every day and even the small engine of 15 HP could also be operated for an hour every day. Another very important output of such smaller unit was estimated to be quantity of usable slurry produced in every house and this was observed to the extent of 145-150 l of slurry every day which if stored properly could be around 1000 l every week. Thus, by investing the Rupees 15000 in installation and running of the family size unit of bio-gas, there was saving to the extent of Rupees 33000 per family per year and the net profit in the first year was 120% higher (Rupees 18000) of the operational cost whereas in the second year and subsequent years, the net profit was computed to be 200% higher of the investment. Other intangible benefits of biogas as experienced by the respondents were reduction in drudgery among the women and lessoning the pollution at the household level. Few constraints were also delineated by the users of the biogas.

Keywords

• Biogas plants
• Biogas slurry
• Biogas technology
• Constraints
• Economics of biogas