Energy from waste
Every year, about 55 million tonnes of municipal solid waste (MSW) and 38 billion liters of sewage are generated in the urban areas of India. In addition, large quantities of solid and liquid wastes are generated by industries. Waste generation in India is expected to increase rapidly in the future. As more people migrate to urban areas and as incomes increase, consumption levels are likely to rise, as are rates of waste generation.
It is estimated that the amount of waste generated in India will increase at a per capita rate of approximately 1-1.33% annually. This has significant impacts on the amount of land that is and will be needed for disposal, economic costs of collecting and transporting waste, and the environmental consequences of increased MSW generation levels.
Waste can be broadly classified into
- Urban Waste
- Industrial Waste
- Biomass Waste
- Biomedical Waste
Urban waste includes Municipal Solid Waste, Sewage and Fecal Sludge, whereas industrial waste could be classified as Hazardous industrial waste and Non-hazardous industrial waste.
Most wastes that are generated, find their way into land and water bodies without proper treatment, causing severe water pollution. They also emit greenhouse gases like methane and carbon dioxide, and add to air pollution. Any organic waste from urban and rural areas and industries is a resource due to its ability to get degraded, resulting in energy generation.
The problems caused by solid and liquid wastes can be significantly mitigated through the adoption of environment-friendly waste-to-energy technologies that will allow treatment and processing of wastes before their disposal. These measures would reduce the quantity of wastes, generate a substantial quantity of energy from them, and greatly reduce environmental pollution. India’s growing energy deficit is making the government central and state governments become keen on alternative and renewable energy sources. Waste to energy is one of these, and it is garnering increasing attention from both the central and state governments.
According to the Ministry of New and Renewable Energy (MNRE), there exists a potential of about 1700 MW from urban waste (1500 from MSW and 225 MW from sewage) and about 1300 MW from industrial waste. The ministry is also actively promoting the generation of energy from waste, by providing subsidies and incentives for the projects. Indian Renewable Energy Development Agency (IREDA) estimates indicate that India has so far realized only about 2% of its waste-to-energy potential. Energy can be recovered from the organic fraction of waste (biodegradable as well as non-biodegradable) through thermal, thermo-chemical, biochemical and electrochemical methods.
Compared to Landfilling waste, Waste-to-Energy facilities offer several advantages. Resource savings and recovery greatly expanded. Waste to Energy is a Net Greenhouse Gas Reducer. Methane is a greenhouse gas having more than 20 times the potency of carbon dioxide and is ranked as a dangerous contributor to climate change. Waste to energy facilities avoid the production of methane while producing almost ten times more electricity from each ton of waste compared to landfills. And, waste to energy facilities are the only solid waste disposal option with state-of-the-art air pollution control technology. WTE facilities, unlike wind and solar, are capable of providing baseload renewable electrical power (baseload meaning 24/7 availability).
Waste to energy facilities typically reduce waste volumes by 90%. Fewer and smaller landfills are needed to process ash and this protects a valuable natural resource – land. With a waste to energy facility in a community, shorter trucking distances result in less air pollution, less truck traffic. Large regional landfills are often located long distances from the communities using them.
62 million tonnes of MSW are generated annually in urban areas, more than 80% is disposed off indiscriminately at dump yards in an unhygienic manner. This waste has a potential of generating 439 MW of power; 1.3 million cubic metre of biogas per day or 72 MW of electricity from biogas and 5.4 million metric tonnes of compost. 62 million tonnes annual generation of MSW will need 3, 40,000 cubic meter of landfill space everyday (1240 hectare per year) if continued to be dumped.
As per CPCB data of 2012 municipal authorities have so far only set up 279 compost plants, 172 biomethanation plants, 29 RDF plants and 8 Waste to Energy (W to E) plants in the country (Many of the above are not even working).
68% of the MSW generated in the country is collected of which, 28% is treated by the municipal authorities. Merely 19% of the total waste generated is currently treated. The remaining waste is disposed off at dump sites / landfill sites untreated. The enormous quantity of MSW (62 million tons per year), generated if successfully managed will dramatically reduce the potential of disease burden and enhance public benefit. Only 22 States/UTs have set up processing and disposal facilities and the rest of the States/UTs have made no effort till 2013
The annual rate of growth of urban population in India is 3.35% (Census of India, 2011). The proportion of population living in urban areas has increased from 17.35% in 1951 to 31.2% in 2011(Census, 2011). By 2020 the Urban Population will be 50%.
India has achieved multifaceted socio-economic progress during the last 64 years of its independence. However, in spite of heavy expenditure by Civic bodies, the Management of Municipal Solid Wastes (MSW) continues to remain one of the most neglected areas of urban development in India. Piles of garbage and wastes of all kinds littered everywhere have become common sight in urban life. For most of urban local bodies in India, solid waste is a major concern that has reached alarming proportions requiring management initiatives on a war-footing.