— Aishwarya Sanas

(The Indian Express has launched a new series of articles for UPSC aspirants written by seasoned writers and scholars on issues and concepts spanning History, Polity, International Relations, Art, Culture and Heritage, Environment, Geography, Science and Technology, and so on. Read and reflect with subject experts and boost your chance of cracking the much-coveted UPSC CSE. In the following article, Aishwarya Sanas, a doctoral researcher working on the politics of cryosphere and global environmental governance, analyses the potential of waste-to-energy.)

The Swachh Bharat Mission (SBM) Urban 2.0, launched in 2021, is crucial for improving waste management.  However, three years later, big cities are yet to clear any land in half of their legacy landfill sites, with only 38 per cent of the total dumped waste being remediated so far, government data shows. It underscores the need for more effective strategies and resources to overcome the obstacles in waste remediation, and draws attention to the significance of waste-to-energy technologies.

While waste remediation involves processes that clean up and rehabilitate contaminated land, waste-to-energy technologies convert non-recyclable waste materials into usable forms of energy, such as electricity or heat. Let’s explore the potential and future applicability of waste-to-energy technologies. 

The problem of the ‘modern’ kind of waste goes back to the Industrial Revolution that began in the mid-eighteenth century. As production was scaled up and factories increasingly relied on power-driven machines and sophisticated technologies to boost output, the generation of waste became inevitable. Waste refers to materials that are no longer needed in the production and consumption cycle.

The United Nations Statistical Division Glossary of Environmental Statistics defines waste as ‘materials that are not prime products for which the generator has no further use in terms of his/her purposes of production, transformation or consumption, and of which he/she wants to dispose’. Appropriate disposal of waste is very important but at the same time difficult to achieve due to logistical, economic, and environmental factors. There is no waste in nature because all natural by-products are recycled and reused in the ecosystem. 

Human activities, on the other hand, generate different types of waste, such as municipal solid waste, hazardous waste, radioactive waste, bodily waste, etc. These waste forms cannot be readily used in nature, are non-recyclable, and may have detrimental effects on human health and the environment.

Currently, global waste production amounts to 1.3 billion tonnes annually, and it is projected to rise to 2.2 billion tonnes by 2025. Resultantly, waste management has become an important global agenda and a national policy concern. 

Traditionally, waste management involved disposing of waste directly into the environment, such as dumping it in faraway places, into the ocean, or in landfills. However, these methods are no longer sustainable due to environmental impacts. A modern-day solution to waste management is the conversion of waste into energy in the form of heat or electricity for further use through waste-to-energy technologies. 

Waste-to-energy technologies serve two purposes: (a) managing large-scale waste generated from household, municipal and industrial activities and, (b) meeting the rising energy demands. Simply put, ‘waste-to-energy refers to a series of technologies that convert non-recyclable waste into some usable forms of energy’. 

These technologies are different or upgraded versions of the existing waste management technologies, for they are designed to generate fuel or gas as one of their end products, which can then be used to produce heat and electricity.  

These are multi-step processes that can be achieved through various techniques. Several waste-to-energy systems have been developed to cater to different kinds of waste. Waste-to-energy technologies align with the United Nations Sustainable Development Goals, particularly SDG 7 (Affordable and Clean Energy) and SDG 11 (Sustainable Cities and Communities). 

They also have the potential to reduce waste generation, minimise the adverse impacts of non-recyclable and toxic waste on the environment, and support the adoption of a circular economy. Several factors influence the selection of suitable technology, including waste composition and characteristics, labour skill requirements, geographical locations, and financial, logistical and technical capabilities. 

Moreover, appropriate information and research around the waste-to-energy nexus are crucial for decision-makers to make an informed decision on the feasibility of waste-to-energy as a sustainable pathway for waste management and renewable energy generation. There are two main conversion processes: biochemical and thermochemical. These technologies require specific kinds of pre-treatment for waste materials such as sorting, shredding, drying, etc.

Thermochemical Technologies – These technologies generally include three methods: incineration, pyrolysis and gasification. 

(i) Incineration is one of the most prevalent technologies. It involves burning waste materials at high temperatures in a specific kind of furnace called incinerators. Incineration is particularly suitable for heterogeneous waste, which includes mixed waste like food, garden, plastic and paper. It is estimated that 70 to 90 per cent of waste is treated by incineration. This technique is appropriate for wastes with high caloric value as well as for non-hazardous municipal waste.

(ii) Pyrolysis breaks down inorganic (or largely plastic) waste in the absence of oxygen to produce fuels in all three states of matter such as char, pyrolysis oil and syngas. It is an old technology that was used to produce charcoal from wood.

(iii) Gasification is an advanced thermal treatment that involves the decomposition of carbon-rich municipal waste to produce syngas or producer gas (a combination of several gases such as hydrogen, carbon monoxide, methane). This is a well-established technology in the petrochemical and power industries. Pyrolysis and gasification are better suited for homogenous waste types.

Biochemical technologies: The decomposition of biodegradable organic components occurs through biological processes under the influence of bacteria. This includes anaerobic digestion (AD) and landfilling.

(i) Anaerobic Digestion (AD) is appropriate for organic waste (kitchen and garden) where micro-organisms are broken down into biodegradable material in the absence of oxygen. One of the end-products is biogas, which is used to generate heat or electricity. This method can occur naturally or can be engineered in bio-digesters and sanitary landfills.

(ii) Composting and landfilling involve burying of waste accompanied by deploying landfill gas recovery systems. Although landfilling is less expensive, it is environmentally detrimental due to the release of toxic and obnoxious gases.

Both thermochemical and biochemical technologies contribute to the circular economy by reducing waste and recovering energy.

However, several waste-to-energy systems have been deployed unevenly across different regions. According to some researchers, at one point, nearly 800 thermal waste-to-energy plants were functioning in just 40 countries that treated 11 per cent of global municipal solid waste. Developed countries such as Germany, Japan, the US and France have a large number of plants, almost amounting to 200 as of 2023.

In contrast, regions such as Asia, Africa and South America do not have as many plants as the developed countries. For instance, Ethiopia installed its first incineration plant in 2017, making it the first sub-Saharan African country to have its own plant, though its capacity was just 55 MW.

Other developing countries such as China, India, and Malaysia have seen significant improvement in installing small-scale household digesters of anaerobic digestion. 

This has revealed a tendency in the global waste-to-energy dynamics where developed countries are preferring thermochemical technologies due to a large share of industrial waste; and developing countries are veering towards biochemical technologies due to a high proportion of waste being household, agriculture or garden.

In India, the first waste-to-energy plant was established in 1987 in Timarpur, Delhi by a Danish company with 300 tonne- capacity. According to a study, there are 12 operational and eight non-operational waste-to-energy plants in India in 10 states as of November of 2022. There are several policy measures in place to promote waste-to-energy conversion across the country. 

These policies are implemented through the Ministry of New and Renewable Energy and with several other allied ministries and government departments. The MNRE is running a Programme on Energy from Urban, Industrial, and Agricultural Wastes/Residues from FY 2021-22 to FY 2025-26 for the generation of biogas. A lot of rules regarding caloric requirements for using specific technologies have been laid out in the Solid Waste Management Rules of 2016. 

In addition, several state and local-level policies have been implemented across the country. In spite of this, power generation from waste-to-energy in India presents a dismal picture. As of May 2023, the total installed capacity for waste-to-energy is 554 MW, which accounts for only 0.1% of the total energy generated in the country. This is less than all other renewable means of energy generation.

There is a general perception that waste-to-energy plants have failed in India. Commonly cited reasons are administrative delays in getting approval for setting up such plants as well local opposition and protests. This happened in the case of the Bandhwari plant proposed in Gurugram in Haryana in 2021. Other reasons include extremely heterogeneous, unsegregated and poor quality of waste which requires excessive pre-treatment and increases the fuel requirement making the entire process expensive and unviable.

As a result, several waste-to-energy plants in India have been closed. This has raised doubts about the potential and future applicability of waste-to-energy technologies. In comparison to the waste-to-energy technologies, a strong advocacy for reducing waste generation, segregating waste at the source, and achieving a circular economy has emerged.

To sum up, there are several global practices that could be innovated and emulated in India, such as Denmark’s idea of hedonistic sustainability. Although waste-to-energy technologies are very important as they provide solutions for treating the waste generated by modern industrial societies and reducing environmental pollution, achieving sustainability targets, and lowering greenhouse gas emission, numerous policy and technical issues require attention. Waste-to-energy could significantly contribute to sustainable growth, development, and job creation if deployed effectively.

How do you define waste-to-energy? Discuss the two main conversion processes in waste-to-energy technologies.

How do waste-to-energy technologies contribute to solving the challenges of waste generated by modern industrial societies?

What are the impediments in the effective deployment of waste-to-energy technologies in India?

What are the potential benefits of achieving sustainability targets and lowering greenhouse gas emissions through waste-to-energy technologies?

What are some global practices that could be adapted for waste management in India?

(Aishwarya Sanas is a doctoral researcher at Shiv Nadar Institution of Eminence, Delhi NCR)

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