Solid waste is a growing problem that needs to be addressed with the most efficient solutions. Waste-to-Energy, which is among a few probable solutions, comes with certain drawbacks. As a Japanese proverb says, “A vision without action is daydream, action without vision is nightmare”. When an action is initiated to resolve an issue, the probable fallouts should also be analyzed. Is it improving waste management & preventing more waste piling up at dump yards or increasing our carbon footprint?
India generates 62 million tons of solid waste every year. This is one of the major environmental challenges we face today. With rapid population growth and urbanisation, the global annual waste generation is expected to increase by 70 per cent from 2.01 billion tons in 2016 to 3.40 billion tons by 2050, according to World Bank. Countries from all over the world are trying to find feasible solutions to cope up with the volumes of waste generated by the increasing urban population and waste-to-energy is one among them. Waste-to-Energy (WTE) is a term that is used to describe various technologies that convert waste into usable forms of energy including heat, fuel and electricity. It sounds like a foolproof solution to many developing countries that recycle as much as they can and convert the rest to energy, but one needs to consider whether it is the best solution.
No doubt, converting waste-to-energy can help to decrease the quantity of waste by 95 per cent and reduce the solid quantity of the original waste by 80-85 per cent depending on the components of the solid waste especially in our country where landfills exist in large numbers. It also helps in controlling generation of methane gas and other toxics, which are released when the waste starts decaying in landfills and thus prevents contamination of soil.
Like every solution, waste to energy also has its pros and cons. Installation of waste to energy plant is expensive, from the cost of establishing the infrastructure to the costs of operating the plants. In addition, a waste to energy plant requires trained and devoted staff to operate it. Need of regular maintenance adds to the already high costs of its operation.
Indian examples
Pune Municipal Corporation (PMC) in alliance with Concord Blue Technology Private Ltd. adopted a similar system taking care of 50 per cent of the city’s waste. A ‘gasification-reformer tower’ which is a 10 MW plant processes 650 tons per day. The tipping fee for the tech solution providers was around Rs 300 per ton. The cost of the plant was 14-15 crore per MW with the generated cost of electricity coming to Rs 13 per unit. However, the normal existing tariff of electricity in Pune is Rs 4.67 per unit on consumption of 0-100 units, Rs 6.58 for 101-300 units, and Rs 8.57 for 301-500 units.
Similarly, Tamil Nadu hosted 50acres site for a gasification project worth Rs 100 crore ($18.5 million) with a public-private partnership under the Design Build Operate and Transfer (DBOT) model, to process 300 tons of solid waste on a daily basis, generating around 3 MW of electricity costing Rs.6.28/ kWH. The existing tariff of electricity in Tamil Nadu is Rs 1.05 per unit on consumption of 0-200 units, Rs. 2.5 for 200- 500 units, and Rs. 4.5 for the consumption above 500 units.
A waste to energy plant uses combustion as a process to consume waste, but its efficient functioning requires segregated waste. Or else there is possibility of pollution. Therefore, consumers need to adopt a change in the attitude towards the advantage of availability of WTE plants and segregate the waste optimally before discarding it. In India, WTE plants process 5,300 tons of garbage to produce 63.5 MW per day. According to a 2015-16 report by the Ministry of New and Renewable Energy (MNRE), this capacity can be enhanced to 1,075 MW by 2031 and to 2,780 MW by 2050. Since 1987, 15 WTE plants have been set up across the country. However, seven of these plants located at Kanpur, Bengaluru, Hyderabad, Lucknow, Vijayawada and Karimnagar have been shut down.
Mostly, waste to energy plants were designed to function successfully in-developed countries where segregated waste is fed to the plant. Currently, process of segregation is not much in practice in India, which makes it difficult to identify a suitable technology. Hence, segregation of waste at source plays a vital role in deciding the success of a WTE project.
Many environmentalists are expressing their concern that people think burning unsegregated waste is easier and more economical than recycling. There is a fear that surrounds the burning of waste because it may encourage people to forgo recycling if it is easier and more economically feasible to dump all waste into incineration plants without sorting it
Recycling – A better option
Recycling is considered one of the best and effective ways to keep the environment safe. Recycling and composting is a combination that can save three to four times more energy than an incinerator can produce. Moreover, recycling reduces massive amounts of CO2 emissions. Many environmentalists are expressing their concern that people think burning unsegregated waste is easier and more economical than recycling. There is a fear that surrounds the burning of waste because it may encourage people to forgo recycling if it is easier and more economically feasible to dump all waste into incineration plants without sorting it. The energy produced by WTE plants most commonly generates electricity for homes. Each ton of waste processed, generates around 500kWh of electricity, which is enough to power 15 average households for a day. However, recycling turns out to be a better option for waste management than a waste to energy plant. The energy produced by the plant is comparatively less than what is saved by recycling the same amount of waste. In addition, the amount of energy produced depends highly on the waste material fed to the plant. For example, recycling one ton of aluminium saves 14,000kWh of electricity, which is enough to power 15 households for four weeks.
According to the US Environmental Protection Agency (EPA), burning waste materials generates high amount of toxic gases than burning of natural gas but comparatively lesser than coal. Incineration of certain kinds of waste materials can result in emission of greenhouse gasses such as nitrous oxide, methane (CH4) and more. The byproducts of some burning methods contain heavy metals and many other toxic substances, which include furans and dioxins. But if waste materials are carefully sorted out, it can significantly lessen the percentage of greenhouse gas emissions.
We cannot fully ignore the benefits of using WTE plants since modern technologies have significantly lessened the amount of pollution resulting from burning waste and landfilling which is even more harmful and damaging to our environment. Recycling is obviously a better option than WTE. But to generate energy from the waste materials we need to first segregate the waste optimally. Therefore, recycling and WTE can work together and can reduce the amount of waste sent to landfills. Our main motive should be to come up with the most effective way of disposing the waste without harming the environment and preserving our natural resources.