Stubble burning crisis: Why thermal power plants in Delhi-NCR have been slow in adopting biomass co-firing

The ‘stubble-burning season’ is upon us and has already triggered an inflow of statements from ministers and government officials. In the last couple of years, the government has tried to tackle the issue by bringing the focus on ex-situ mechanisms of handling biomass or crop residue management (CRM) such as biomass co-firing and production of bio-CNG. These were promoted apart from the long-advocated in-situ mechanisms such as promoting use of happy seeders and super seeders.

Co-firing five to seven per cent biomass pellets in thermal power plants can prevent 38 million tonnes of carbon dioxide every year, Finance Minister Nirmala Sitharaman had said in her budget speech in 2022. 

A key policy of the Centre, biomass co-firing in coal-based power plants will work towards energy security, reduced use of fossil fuels and at the same time to increase income of farmers, according to Union Power Minister RK Singh.

The Centre for Science and Environment (CSE) conducted a survey-based study last year to understand the on-ground progress of the policy implementation on co-firing biomass in coal-fired thermal power plants in the National Capital Region (NCR). 

The study showed that till the end of 2022, co-firing was done only intermittently in all the 11 coal power plants in NCR and most of the plants had so far only conducted trial runs.  

The situation does not seem to have improved since then: Only three plants have reported higher quantities of biomass co-firing since December 2022 till August 2023, government data showed. These included Indira Gandhi Supercritical Thermal Power Plant (central), Harduaganj Thermal Power Station (state) and Mahatma Gandhi Thermal power station (private). 

Change in status of biomass co-firing in coal thermal power plants in December 2022 vs August 2023

We tried to explore the reasons behind this delay in implementation of 5 per cent of co-firing by coal thermal power plants (TPP) as mandated by the Commission for Air Quality Management (CAQM) for NCR and adjoining areas as well as by the Union Ministry of Power (MoP). Here are our findings: 

The Harduaganj Thermal Power Plant attributed its success in co-firing biomass to regular and adequate supply of biomass by the vendors in the recent past. They also informed CSE that all the three vendors who submitted bids quoted prices below the benchmark of Rs 2.32 per thousand kilo calories (Kcal) excluding Goods and Services Tax and transportation, for supply of 90,000 tonnes of non-torrefied biomass pellets. 

However, the supply chain needs further strengthening as the last order fulfilled for the plant was in July this year and the next delivery is scheduled for the coming November.

Timeline of events related to biomass co-firing in coal thermal power plants

Source: Author created

Haryana Power Generation Corporation Limited (HPGCL), on the other hand, had to make provision for extensions for fulfilment of its tenders for supply of torrefied biomass pellets. All the three plants of HPGCL — Panipat TPS, Rajiv Gandhi TPP and Yamunanagar TPP — can only co-fire torrefied biomass (biomass pellets processed at 250-350 degrees Celsius) due to technical limitations. There is dearth of torrefied biomass pellet manufacturers in the market and therefore, the plants that rely on it face delays in implementation of biomass co-firing in their plants. 

The HPGCL informed CSE that they have awarded a tender for supply of 300,000 tonnes of biomass pellets to be fulfilled in January or February next year. The plant has procured torrefied biomass pellets at the rate of Rs 2.32 per 1,000 Kcal including GST and transportation. 

The officials of HPGCL, however, have apprehensions about the regular and adequate supply of the biomass pellets despite the huge investment made by the plant in its procurement. 

In case of Mahatma Gandhi TPP, the plant has identified the supply chain but faces technical limitations of only being able to co-fire up to 1.5 per cent biomass pellets instead of 5 per cent as mandated. In order to scale up co-firing, the plant will have to make some major investments, which will have implications on the electricity tariffs. 

While HPGCL and Mahatma Gandhi TPP have successfully placed orders for torrefied pellets, Talwandi Saboo TPP is still struggling to find vendors for its plant. The plant has also raised the issue with both MoP and CAQM. 

The lack of a tried and tested technology for manufacturing of terrified biomass pellets is cited as the main reason for this supply gap. The plant had given orders for torrefied biomass pellets to a vendor at thrice the market price of Rs 7 per kg. But the pellets supplied had 50 per cent volatile matter against a technical requirement of 22 per cent. Likewise, the officials opined, several plants have placed orders, but none are actually able to get the feed for their plants.

Most other plants are procuring biomass pellets from vendors, but Indira Gandhi TPP has also issued tender for supply of 25,000 tonnes of raw materials such as paddy straw, mustard straw, cotton stalk and other crop-residue for setting up an in-house pellet manufacturing unit in the coming months. The plant is currently procuring 700-800 tonnes per day (TPD) of biomass pellets against a requirement of 1,000 TPD to meet the target of 5 per cent co-firing. 

Sources revealed that the Lehra Mohabbat TPP, too, has signed an agreement with NTPC for establishment of a non-torrefied biomass pellet manufacturing unit in its premises, apart from procuring biomass pellets through the tendering process.

Dadri Thermal Power Plant was the first plant to demonstrate biomass co-firing in the country. But its records showed that the plant has co-fired only 36 tonnes since December 2022. The officials cited lack of supply of pellets by the manufacturers as the primary reason for not making much progress in co-firing biomass in the past several months.

Despite several CAQM directions to TPPs to adhere to biomass co-firing, continuous efforts by the MoP (SAMARTH) to enhance capability and capacity of pellet manufacturing units, it seems unlikely that biomass co-firing will have any significant impact on limiting farm fires this season at least. 

Stubble burning is time-sensitive and the government needs to plan well in advance considering all the ground practicalities. Our next course of action needs to be in tandem with the time it takes right from floating of tenders by coal TPP to awarding of these tenders and procurement of crop residue by pellet manufacturers to processing it for supply to power plants.

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