Illustration: Tarique Aziz
Illustration: Tarique Aziz

A burning question

Waste-to-energy plants are being touted as a wonder solution for garbage management. But how feasible is this option?
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Urban India produces around 150,000 tonnes of municipal solid waste (MSW) every day, of which only 25 per cent is processed. The rest is dumped or burned in open areas. By 2030, the figure will be a staggering 450,000 tonnes per day. How will our cities manage this gargantuan amount of waste? The go-to answer for city planners and policymakers is to burn MSW in waste-to-energy (WTE) plants. The logic is that instead of spending time and resources in segregating waste, the best way is to collect unsegregated wastes and process them in WTE plants to produce electricity or oil. Companies are offering this as a miracle solution to cities across the country. The government has bought this logic and provides several subsidies to promote WTE plants, including financial incentives to cities to supply garbage at project sites and for providing land at a nominal rent. These subsidies account for about 40 per cent of the cost of WTE plants.

WTE is not a new technology. The first WTE plant came up in Timarpur in Delhi in 1987. 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, but half of them have closed down. The remaining plants are under scrutiny for environmental violations. For example, in 2017, the National Green Tribunal slapped a fine of Rs 25 lakh on Okhla WTE plant in Delhi for polluting the environment.

So, why are WTE plants not working in India? The fundamental factor is the quality and composition of waste. MSW in India has low calorific value and high moisture content. As most of the waste is unsegregated, it also has a high content of inert materials like soil and sand. 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.

The second reason is economics. Despite the subsidies, the electricity produced from WTE plants is very expensive. Compared to Rs 3-4 per 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.

The third reason is the environmental and health impacts. Experience across the country indicates that WTE plants are not able to meet environmental norms. The reason again seems to be the highly variable and poor quality of waste that the plants are not able to burn properly. As they have to handle vast quantities of mixed waste, housekeeping is extremely challenging, leading to odour and visual pollution. People do not want smelly and polluting plants near their homes. So, should we be building large number of WTE plants in the country?

The Solid Waste Management Rules, 2016, clearly state that only non-recyclable high-calorific fractions such as used rubber tyres and multilayer plastics should be sent to WTE plants. Of the 150,000 tonnes of generated every day, only about 15 per cent can be classified as non-recyclable and high-calorific-value waste. This translates to about 25,000 tonnes per day (TPD) of waste. But the total waste treatment capacity for 40-odd under-construction and proposed WTE plants is already over 30,000 TPD. The question is: where is the waste to burn in WTE plants?

It is important for our city planners to understand that WTE plants have a role, but it is not for burning mixed waste. They should not be promoting these plants for mixed waste, otherwise these plants would end up as white elephants just like some of their predecessors.

(This article was first published in Down To Earth's print edition dated March 16-31, 2019)

Down To Earth
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