In rural India a significant proportion of households – especially the poor ones - have no access or unreliable access to electricity for lighting and other energy-related needs. Instead they have to rely on kerosene lamps and other energy sources that are more expensive and insufficient for their needs. Extending distribution lines to link remote villages to the grid is often not a feasible option for the provision of electricity. As a result, about 10% of all villages are still not connected to the grid. And even those households connected to the grid usually only receive electricity for a few hours per day due to power shortages. Although alternative generation technologies are available, they have only had limited success in the past. Technologies proved to be unsuitable for rural families, unaffordable or unsustainable because they were one-time donations that failed when replacements were needed.
To address these problems the Regional Energy Initiative Asia, as part of the International Energy Initiative (IEI), initiated a project to demonstrate the benefits of electricity generated through a biogas-fuelled engine for household and community needs. The measures adopted included the establishment of a dairy, the generation of electricity with biogas from the manure of the dairy cows and the extension of the local electric grid lines to homes without access.
The village selected for the implementation of this pilot project was chosen by IEI based on selection criteria and its population demonstrated willingness and a desire to participate. The village consisted of 51 households, of which 10 had no regular connection to the electricity grid. The villagers suffered from poverty and electricity shortages were common, but there were also a sufficient number of commercial users in the village who were able to pay the higher commercial unit prices.
Technology, Operations and Maintenance
The construction of the biogas digester and the dairy were undertaken simultaneously, so that as soon as the cows were bought, the dairy waste could be deposited for digestion. In this way a delay due to the retention period of at least 45 days for the biogas formation could be avoided.
Starting the dairy required three key steps: a) the construction of the dairy buildings; b) the selection and purchase of cows; and c) the training of the new dairy employees in taking care of the cows and the overall running of the dairy. The newly constructed dairy could house a total of about 64 cows.
The construction of the 35 m3
biogas digester also involved different working stages. First the pit of the digester with a diameter of 4.6 m and a depth of 6.7 m had to be trenched and the masonry lining for the digester had to be constructed. Then the guide frame and gas-holder tank were transported to the village and installed on site. To ensure durability and prevent corrosion of the gas-holder drum it was treated and later painted with epoxy-coal tar. Furthermore the installation of the biogas generation system required the construction of an inlet tank, into which the dung-water slurry mixture is fed, and an outlet tank in which the effluent is collected. The digester was later connected to both tanks with PVC piping. The daily fuelling of the digester consists of 720 kg mixture of dung and water. The waste from the cattle-sheds is collected daily in bins which are then taken to the input tank, where the manure is mixed with equal amounts of water. To obtain an adequate water supply for this mixture process and for the cows, an existing well that previously had a manual pump was fitted with an electrically-operated pump. To generate electricity from the produced biogas the digester's gas outlet was connected to an engine and an engine room with an engine generator of 20 kVA/16 kW capacity suitable for the rural conditions was installed. This spark-ignition, self-starting, 4-stroke engine is water-cooled, with an air and fuel controller system to ensure efficient working from no load to full load.
Two people from the village were recruited to operate the engine generator. They were trained during the installation period by representatives from the engine manufacturer. As well as the operational duties, the two people are also in charge of recording hours of daily operation, amount of gas used and the amount of electricity generated.
Financial Issues and Management
Affordable home and community lighting is supported by the revenue generated by higher tariff commercial consumers and the income from the dairy business. The electricity tariffs are equal to the tariffs charged by the Bangalore Electricity Supply Company (BESCOM): about €0.03/kWh for households and community services and about €0.09/kWh for commercial consumers (in 2012).
The electricity use of each household and the public installations is monitored and the engine operators are responsible for billing and collecting the fees from households for the electricity used.
Instead of relying on energy from fossil fuels the households now receive energy from a renewable and locally available energy source, reducing the negative impacts on the environment. In addition, fluorescent tubes and compact fluorescent lamps were installed in public places to improve the energy-efficiency of the lighting in the village. The project helped to avoid CO2.
The project promotes joint ownership, in the form of a community co-operative, to achieve the advantages of scale and as a result to reduce the costs for individual households. To ensure the sustainability of the project the improved energy access was combined with income-generating activities, so that the project would be economically viable even while providing low-cost electricity to the poor.
Seven local people are employed in the daily operation of the dairy. Of these, two were already experienced and the others received training. In addition, two people are employed to operate the biogas system and the electricity grid.
Results & Impact
As a result of this project, 275 people gained access to a reliable electricity supply from a renewable energy source. 10 households that were not previously connected to the electricity grid became connected. Employment opportunities for 9 community members were created. Apart from the electrification at household level, there is now an electricity supply for additional community applications such as street lighting and internal lighting in a primary school, a temple and a mosque.
Theoretically the project design and technology have good replication potential. As described before there are many rural areas in India that have either no access to electricity or receive only an unreliable power supply from the national grid. Another potential success factor is that biogas technology has been proven to be effective in India and is available in the country. However, the big problem will be financing the measures. To overcome this obstacle IEI is planning to meet with the regional state electricity distribution authorities and discuss further options for replication.
The introduction of a new technology to a village requires the simultaneous training and knowledge transfer to locals so that the technology can be maintained and repaired locally after the project itself has ended.
It is also important that the project village is carefully chosen with regards to common land availability for the installations, willingness of the community to participate, proximity to veterinary facilities and milk collection centres, as well as the geographical set up of the village and its houses.