Major part of Indian imports is petroleum products and hence a major contributor to both Current Account and Fiscal Deficits. For a developing country like India which is on a growth path and is energy hungry to aggressively explore various alternate sources of energy. Biogas, a by-product of agricultural, livestock and human waste can be a good bet, bio-gas generation process can lead to reduced dependence on LPG, expensive power generation sources and chemical manure (a petroleum by-product). Usage of bio-gas can help reduce pollution, deforestation, time and resources spent on waste disposal etc. Subsidy bill which is always a head ace for government can also be brought under control apart from reducing our dependence costly $ for importing crude. Since Bio-gas can be produced and distributed locally it can reduce consumption of petrol and diesel spent on transportation.
Biogas has a huge potential. It is estimated that a typical urban household can save upto 100 kg of LPG or 250 litres of kerosene per year which is equivalent to 300 to 600 kg CO2 per year by embracing biogas. A rural family could save about 3 tonnes of wood per year, which would generate about 5 tonnes CO2 if burnt. LPG usage can be reduced by more than 60% - 70% by adopting biogas.
Biogas production can start from individual houses/apartments and go on to hotels, marriage halls, industries, municipality wards and then at cities/towns level.
Individual houses and apartments
Portable biogas units are ideal for single families of 4-5 members. The approximate waste required per feed is about 2 kgs of kitchen waste and water. The gas generated is for 2 -2.5 hrs cooking time. 2.5 kg – 5 ton digesters can be installed based on the amount of waste generated, latest digesters do not even produce smell from 30 days old garbage. The latest digesters need not be underground fitted but rather be placed on terrace, common passage etc thus avoiding space constraint issue.
Hotels and marriage halls
In marriage halls, canteens, hostels, restaurants etc generate wet waste of same nature and are easier to handle. Installing small to medium size Biogas generation units can substantially reduce their cost of operation as biogas generated can be supplemented for using as cooking fuel. Hassles involved in waste disposal can also be reduced.
Handling and disposing sewage and garbage are two big problems for local municipality in cities. Building bio-gas generation units of 1 TPD to 2 TPD capacities in each ward (4-5 wards together) can help in generating gas for cooking or electricity which can power street lamps. Processed sewage water can be used for watering parks thus reducing the dependency on fresh water, and solid residue which is manure can be either used within the wards or can earn revenue if sold. When self reliance is better than dependence, embracing bio-gas as an energy and fertiliser alternative can help India being self reliant to a great extent. Though technologies required for generating biogas from both solid and liquid waste is already available it needs to be supplemented by mindset change from both people and government. Initial encouragement would be required from government similar to the assistance provided for solar energy as it’s a win-win situation.
(The writer is an independent environment analyst)