Government releases policy for co-firing municipal solid waste charcoal in coal thermal power plants

The Union Ministry of Power, Government of India, released a comprehensive policy on co-firing biomass and torrefied charcoal from municipal solid waste in coal-based thermal power plants (TPP) on November 7, 2025. This follows the ministry’s revised policy on Biomass Utilisation for Power Generation through Co-Firing in Coal-Based Power Plants issued on October 8, 2021 and a modification on June 16, 2023. 

The ministry has now issued a consolidated policy that supersedes all earlier versions to include torrefied charcoal from municipal solid waste in the existing framework for biomass co-firing.

What the policy states

The availability of biomass in India is estimated at 750 million tonnes every year, of which 230 million tonnes is agricultural residue considered to be surplus, the policy states.

For municipal solid waste (MSW), it notes that about 150,000 tonnes is generated per day in urban areas in India (as of 2023). It further states that 75 per cent of this waste is processed by various industries for miscellaneous uses, while the remaining 25 per cent remains unmanaged. The objective, as mentioned, is to utilise surplus biomass and residual MSW in an environmentally friendly manner to reduce greenhouse gas emissions, while also supporting the government’s Swachh Bharat Mission.

The policy directs all coal-based thermal power plants in Delhi-National Capital Region (NCR) to use a 5 per cent (by weight) blend of biomass pellets and an additional 2 per cent blend of either biomass pellets or torrefied charcoal made from MSW, along with coal, with effect from financial year 2025-26. Other thermal power plants outside NCR will have to co-fire 5 per cent (by weight) of biomass pellets or torrefied MSW charcoal from 2025-26. 

The torrefaction level of the pellets used may be based on the original equipment manufacturer (OEM) recommendation for the particular plant. There is also a provision for exemptions on a case-by-case basis, to be examined by a committee comprising representatives of the Central Electricity Authority (CEA), Commission for Air Quality Management in NCR and Adjoining Areas (CAQM), Bharat Heavy Electricals Ltd, SAMARTH Mission, the Union Ministry of Agriculture and Central Power Research Institute.

With respect to the contents of biomass pellets, the policy clearly states that surplus agro-residues not being used for animal fodder may be used for pellet production. It specifies that for TPPs located in NCR and adjoining areas, a minimum of 50 per cent of the raw material in pellets must consist of stubble, straw or rice paddy crop residue sourced exclusively from NCR and adjoining regions.

On tariff determination and scheduling, the policy states that for TPPs under Section 62 of the Electricity Act, 2003, the cost of co-firing biomass pellets and MSW charcoal shall be passed through the Energy Charge Rate (ECR). For TPPs under Section 63, the extra cost may be claimed under the change-in-law provisions; alternatively, if the project has a ‘fuel cost pass-through’ clause in its power purchase agreement, the added cost shall be passed through the ECR. Obligated entities under RCO can meet their obligation by purchasing such co-fired generation.

Impact for thermal power plants

Delhi-based think tank Centre for Science and Environment (CSE) reached out to TPPs to understand how they foresee co-firing MSW charcoal alongside the ongoing biomass co-firing initiative. A senior official at the NTPC Ltd, formerly National Thermal Power Corporation, told us: “NTPC’s flagship plant at Ramna, Varanasi, is a fully operational facility which is successfully processing 500-600 tonnes per day of MSW. It uses an advanced indigenous torrefaction process; a plant that converts urban waste into high-quality torrefied charcoal.” 

“The high-quality charcoal is being transported to and successfully used for co-firing in NTPC’s Unchahar thermal power station, seamlessly integrating into our existing operations to reduce our carbon footprint,” he added. “No further modifications are required in thermal power plant boilers for co-firing MSW charcoal, as we are already firing biomass pellets.”

However, another senior official from a private thermal power company, speaking on condition of anonymity, told us: “Co-firing MSW-derived charcoal along with coal will lead to several operational, technical and environmental challenges. MSW charcoal typically contains high chlorine, alkali metals and heterogeneous components, which can cause increased slagging, fouling and accelerated corrosion of boiler pressure parts, air preheaters and ducting.”

The fuel’s variable calorific value and higher moisture content may result in unstable combustion, reduced boiler efficiency and higher unburnt carbon, he explained. “Additionally, the fine and low-density ash associated with MSW fuels can overload the electrostatic precipitator, reduce particulate capture efficiency and adversely affect downstream systems such as flue gas desulphurisation.”

Co-firing may also raise emissions of dioxins, furans, heavy metals and acidic gases, creating potential compliance risks under environmental norms, the official added. “Handling and storage challenges, including dustiness and fire hazards, further increase operational complexity,” he said.

Monitoring systems and standardisation will also need to be upgraded and established for these additional pollutants such as dioxins and furans, particularly as they are not actively monitored in coal-based thermal power plants at present. “Careful evaluation, controlled blending ratios and continuous monitoring are essential before adopting MSW-charcoal co-firing in existing coal-based units,” the official further explained.

On the policy ecosystem and supply chain, Nivit Kumar Yadav, programme director, industry unit for CSE, said: “The government created the National Biomass Mission and a full ecosystem of support and subsidies to scale and facilitate biomass supply for power plants. A similar initiative and ecosystem would be required for MSW charcoal for it to scale enough in terms of production and supply for the thermal power plants to be able to use it to meet their targets under the comprehensive policy.”

Lessons from waste-to-energy plants

MSW is also the main fuel for all waste-to-energy (WTE) plants in India. There has been long-standing debate on the merits and demerits of WTE plants, which face multiple challenges and concerns over health and environmental impacts due to emissions, proximity to cities, process inefficiency stemming from feedstock quality, and issues of overall economic feasibility.

Tribhuvan Bisht, deputy programme manager for solid waste management and circular economy at CSE, said: “The core challenge of WTE plants is India’s wet, unsegregated, low-calorific-value waste, which burns inefficiently, creates toxic emissions and requires subsidies just to stay operational. Using this same substandard ‘fuel’ for torrefaction to produce so-called biocoal (torrified charcoal) doesn’t solve the problem; it simply shifts it.”

Torrefaction removes moisture and increases energy density, but it does not remove contaminants; it only relocates them, Bisht pointed out. “The chlorine present in plastics and food waste is released as corrosive hydrogen chloride gas, creating acidic liquid waste and attacking plant equipment. The non-volatile heavy metals such as lead and copper from e-waste, batteries or paints don’t disappear; they become even more concentrated in the final biocoal, essentially priming it with catalysts for dioxin formation during co-firing. And because torrefaction temperatures overlap with the melting point of mixed plastics, the molten fraction causes agglomeration and fouling inside the reactor.”

The fundamental lesson remains unchanged: you cannot fix a contaminated feedstock completely merely by changing the process and technology, he reiterated. “The only real solution lies at the source with proper segregation,” Bisht said.

Although source segregation is the real solution to the MSW challenge, a large proportion of waste is still not being segregated, ending up in landfills and leading to health hazards, methane emissions and landfill fires that worsen air pollution in cities. The question is whether TPPs can play a role in addressing this challenge. If they are intended to, it becomes essential for the government and TPPs to examine the issues and challenges associated with using MSW as a fuel. The lessons from the experience of WTE plants in India will be invaluable.