Current Technologies in India aren’t able to cope up with increasing volumes of waste getting generated on an everyday basis by the growing urban population and it’s major environmental challenges associated with transport, treatment, disposal and public health. Use of specialized waste processing facilities to separate recyclable materials thrusts a key role ,but problem lies in disposal of residual waste materials and the required landfill sites to dump or dispose them. So the process of synthesizing heat and electricity ie Energy from waste or WtE(Waste to Energy) Conversion, should be brought into effect for two main reasons. Primary being the growing power demand in a developing country like India where electricity generation is highly required for urbanization and other upcoming technologies like Electric vehicles, IT parks, and Automation technologies. And Secondary reason being that most of the non biodegradable wastes cannot be dumped and to reduce the area occupied by landfill sites to the highest possible level.
The technical process of WtE Conversion:
WtE plant synthesizes both biodegradable and non biodegradable wastes and in particular “conversion of non biodegradable wastes to electricity” has received widespread criticism from environmental activists. There are around 92 WtE plants in India with most of them being failed or closed due to the environmental effects caused by them or due to the least value of energy efficiency ratio ,when compared with other power plants. Almost 100 tonnes of municipal solid waste is being synthesized to generate 1 MW of power.
One Plant that is successful in India should be the Solapur WtE plant that synthesizes 3 TPD(Tonnes Per Day) and generates 3 MW of Electric Power. But 3 MW is such a less value of power being generated when compared with wind and hydro plants( I don’t even take thermal plants into consideration).The Biomethanation plant in Solapur uses methanogens(methane by microbes ) to produce energy .In short ,it converts biogas(CH4) to electricity. Thermophillic Anaerobic digestion Biomethanization process is performed in which organic material is decomposed anaerobically at 50-55 deg C. And this process would reject all waste of size 100 mm and above in order to reduce the amount of CO2 content being generated. But the problem lies with incineration( ie heating) which stands taller as the most efficient method and produces harmful byproducts like flyash,CO2,Mercury, dioxins, lead, and other pollutants that come from burning waste. In terms of climate impacts, incinerators emit more carbon dioxide (CO2) per unit of electricity than coal-fired power plants.
Financial Constraints of WtE Plant:
WtE plants still don’t prove to be a highly feasible because on a study basis biodegradable wastes(eg: vegetable peels, banana skin) tend to be more efficient than plastic and non biodegradable wastes. With increasing population ,Waste generation is estimated to reach a staggering 4.5 lakh tonnes per day by 2030. How will our cities manage this gigantic amount of waste, considering that they struggle to manage even the current quantities in the present day scenario?
For instance, Niti(National Institute of Transforming India) Aayog has, under the Swachh Bharat Mission, set a target of constructing 800 megawatt (MW) of WTE plants by 2018–19, which is ten times the capacity of all the existing WTE plants put together. But in reality only 138.05 MW is being generated as on march 31st 2019.(Source:https://mnre.gov.in/waste-to-energy/current-status#:~:text=Incineration%20technology%20is%20complete%20combustion,elaborate%20air%20pollution%20control%20system.) The Ministry of New and Renewable Energy (MNRE) offers financial incentives by way of interest subsidy to reduce the rate of interest to 7.5%.But still, WTE is not a new technology. The first WTE plant came up in Timarpur in Delhi in 1987. It was designed to incinerate 300 tonnes of waste per day (TPD). But it failed and was shut down soon after. Since then, 14 more WTE plants of 130 MW capacity have been installed in the country. Out of these, seven plants with capacity of 66 MW are closed and the remaining seven plants are operational. So, half of all the WTE plants constructed have closed down. European countries like Sweden, Germany are leading energy producers in the field of Waste to Energy generation. In fact Sweden buys waste from other European countries to burn it in its WTE plants and generate huge MW of energy. So, why are WTE plants not working in India when they are doing reasonably well in developed countries like Germany and Sweden?
What can be done?
The fundamental factor and 1st primary reason is the quality and composition of waste. Solid Waste in India has low calorific value and high moisture content. As most of the waste is unsegregated, it also has high content of inert materials like soil, sand, grit, etc. This waste is not suitable for burning in WtE plants. To burn it, additional fuel is required, which increases the cost of operations as well as pollution. Whereas, Countries like Sweden, Germany are cold countries and they do not have access to renewable sources like solar, hydro and wind.(Wind Energy is sometimes an exception). This has been the main reason why WtE plants in various parts of the nation had to be shut down.
The second reason for WtE plants not working well in India is the economics of these plants. Despite all the subsidies, the electricity produced from WTE plants is the most expensive. Compared to Rs 3-4 /kWh from coal and solar plants, WtE plants sell electricity at about Rs 7/kWh. Discoms are not interested in buying such expensive electricity when cheaper electricity is available. In fact, if subsidies from government are removed, the electricity produced from these plants will simply not be affordable. The third reason is the environmental and health impacts of WTE plants.
WtE plants do not eliminate the need for landfills, though they reduce the quantity of waste sent there. In sum, the reason why WtE plants don’t work in India is because the type of waste we are planning to feed(mixed waste) is unsuitable for this technology. But this doesn’t mean that there is no case for WtE plants in India. There is, but it is not for burning mixed waste.
As our population and economy grows, so will our waste. There is clearly a need for different technologies to manage different forms of waste. WTE plants have a role, but not in the way our government is planning. They should be the last way to manage high-calorific-value waste that cannot be managed by any other technologies. They must, in addition, be operated with the most advanced technologies to contain pollution. Otherwise, we will be creating landfills in the sky instead of on land.