Huge biomass reserve of India can be a source of localised source of electricity. From vegetable waste and rice husk to pine needles, here are a few initiatives from across India
AROUND A thousand families of Thalangi tribal hamlet in Coimbatore district received free television sets from the Tamil Nadu government in 2006. But these were of no use as the houses had no electricity supply. Kerosene was the main source of lighting. Today, it is interesting to see how the hamlet has met all its energy needs and also attained complete sanitation through a biodigester. Though biodigesters have conventionally been used to generate biogas for cooking fuel, examples are cropping up across India to use the same gas for electricity generation, especially in far flung areas. It involves additional steps of cooling down and filtration of the biogas before it is made to run the generator delivering electricity as the end product. The waste slurry can be used as field manure.
According to 2011 Census, nearly 81 million (32.8 per cent) households in India do not have access to electricity and around 74 million rural households lack access to modern lighting services (TERI, 2013). The conventional technologies and grids have failed to deliver. However, electrifying these regions need not necessarily depend on polluting resources like coal or disruptive hydropower. Innovative designs of biomass digesters and gasifiers can be clean, cheap and decentralised sources of energy for these villages. Union Ministry of New and Renewable Energy has supported certain initiatives regarding the same.
Around 81 million (32.8 per cent) households in India do not have access to electricity and 74 million rural households lack access to modern lighting services. The conventional technologies and grids have failed to deliver. However, electrifying these regions need not necessarily depend on polluting resources like coal or disruptive hydropower.
Vegetable waste can turn fans
Thalangi got introduced to biodigester through Non-conventional Energy and Rural Development (NERD) Society which literally ‘empowered’ the village. The plant, using animal waste, is producing 18,000 kWH of power annually. In what can be a perfect answer to India’s sewage problem, NERD also connected toilets in the village to the digester for additional benefit and maximum usage of resources.
A federation of seven women and youth SHGs in the hamlet manages resources like the power tiller, oil engine, tractor, and trailer. Each member pays about Rs 20 per month to the federation for the maintenance of the system. Villagers have also increased the numbers of their livestock by approximately 300 cows, 95 buffaloes, 51 goats, and a few horses which will only help with the power generation.
What NERD did at remote Thalingi village, Biotech implemented at Pathanapuram gram panchayat in Kollam district of Kerala. The panchayat-controlled public market area was facing many health and environmental problems as it generates around 1,000 kg of organic waste. The major contributors were slaughter houses, fish shops and vegetable vendors. To overcome the problem of waste disposal, the gram panchayat approached Biotech which had already set up such systems at various markets, institutes and houses including many connected to lavatories. Biotech conducted an awareness programme to educate the shopkeepers about systematic collection and hygienic disposal of the waste generated in the market and also demonstrated the functioning of the plant.
The panchayat-controlled public market area was facing many health and environmental problems as it generates around 1,000 kg of organic waste. The major contributors were slaughter houses, fish shops and vegetable vendors. To overcome the problem of waste disposal, the gram panchayat approached Biotech which had already set up such systems
Though the plant cost them Rs 26 lakh, it is today generating 90 kWh of electricity to cater to the requirement of all newly constructed fish stalls. It also yields 400 to 500 litres of liquid fertilizer per day. The net annual income from the plant is estimated to be Rs 10.73 lakh which will help the plant recover cost in three to four years. So, not only the waste disposed off well, it also started yielding profit.
Pine needles run the show here
There is another case from Uttarakhand, where gasification process is used to meet multiple demands – cooking fuel, electricity production, enhanced agriculture in the region and most of all, deterring forest fires to a possible extent. Avani Bio Energy is working in the villages of Central Himalayas on pine-needle gasifiers. These gasifiers are fuelled by the pine needles collected from the forest.
The energy model has multifold benefits. Pine needles not only affect the biodiversity of the region, but also forbid percolation of rainwater thus hindering groundwater recharge. The needles being highly inflammable also contribute to the annual forest fires in the hills. In 1999, a devastating fire burnt more than Rs 600 crore of forest wealth in the Garwhal and Kumaon regions. Thus collection of pine needles benefits the environment in a big way.
The energy model has multifold benefits. Pine needles not only affect the biodiversity of the region, but also forbid percolation of rainwater thus hindering groundwater recharge. The needles being highly inflammable also contribute to the annual forest fires in the hills.
The gasifier plant burns these needles under controlled conditions, at high temperature and limited oxygen supply. The resultant charred biomass is further segregated into carbon monoxide, hydrogen and methane gases which are cleaned and cooled to operate a generator that produces electricity. More interestingly, 10 per cent of the residue from the gasifier is high quality charcoal, which is used as cooking fuel instead of fuelwood for which women had to walk for miles. This cooking fuel is cheaper than LGP or kerosene.
Avani started experimenting with the technology in 2009 by setting up a plant to meet its own energy needs. Soon several plants were set up at various villages of the region. Avani has now entered into a tie up with several power companies to provide bio-electricity. A 100-kW gasifier running for 24 hours will require 4,500 kg of pine needles. Thus, there is a good scope of replicating this model in the central and western Himalayan regions where pine needle is found in plenty. A pine forest area of 1 m² can yield 1.19 kg of pine needles. Not just pine needles, there is husk lighting up the remote hamlets as well.
Rice husk is another option
Gyanesh Pandey, founder of Husk Power Systems (HPS), grew up in a village in Bihar that had no access to electricity. It was but natural for him to start thinking about alternative sources of energy which can be generated and utilised at the village level itself.
After completing their studies, Gyanesh and his friend started experimenting with various technologies including polymer solar cells and jatropha-based bio-diesel. But they soon realised how various non-conventional technologies were either not scalable or had practical issues in rural environment. That also happened with the idea of a gasifier-based plant powered by discarded rice husks. Rice mills have long been using husk to partially meet their power needs. However, the gas produced using husk is very dirty and can clog the engine which is why it has to be used in conjunction with diesel. This model can work for rice millers but not for villagers.
Rice mills have long been using husk to partially meet their power needs. However, the gas produced using husk is very dirty and can clog the engine which is why it has to be used in conjunction with diesel. This model can work for rice millers but not for villagers.
However, Gyanesh decided to work solely with husk by ensuring that the engine is cleaned before the gas starts clogging it. That idea not only clicked but HPS is today operating 60 mini power plants lighting up around 25,000 households in over 250 villages. Its power plants come with an operator and a husk loader. The operator carries out the routine maintenance for smooth power production. For maximum utilisation of raw material, the only by-product of the process, the charred husk, is converted into ashballs for use as manure and cooking fuel or for use in the cement industry.
HPS has adopted a unique demand-driven approach and the connection is given only to those villages where at least 250 households agree to take the connection. They submit a token installation charge of Rs 100 per household which not ensures compliance, but also covers a substantial portion of grid distribution expenditure. Since the generators are demand driven, there is no problem in getting back the electricity charges from the villagers.
With a proven record of success as expounded by the stories in these reports, there is much more desired from bio digesters.