Lok Sabha Question No. 1975 (UNSTARRED), answered on 2025-12-11
Subject: Integration of Coal-Fired Power Plants with Renewable Energy
Ministry: POWER
Asked by: Shri Dushyant Singh

## GOVERNMENT OF INDIA

## MINISTRY OF POWER

## LOK SABHA UNSTARRED QUESTION NO.1975 ANSWERED ON 11.12.2025

## INTEGRATION OF COAL-FIRED POWER PLANTS WITH RENEWABLE ENERGY

1975. SHRI DUSHYANT SINGH:

Will the Minister of POWER be pleased to state:

- (a) whether  any  studies  have  been  carried  out  on  the  long-term impact  of  reduced  technical  minimum  load  requirements  on  the lifespan and efficiency of the existing coal-fired power plants in light of the commendable Government initiatives to enhance the share of renewable energy in the India's total energy generation, if  so, the details thereof;
- (b) whether  remedial  measures  are  being  considered  by  the Government  to  address  such  potential  impacts,  if  so,  the  details thereof; and
- (c) whether the Government has any plans to introduce or promote hybrid technologies that can integrate the existing coal-fired power plants with renewable energy sources to ensure optimum efficiency and consistent power supply, if so, the details thereof?

## A N S W E R

THE MINISTER OF STATE IN THE MINISTRY OF POWER

(SHRI SHRIPAD NAIK)

(a):  The Central Electricity Authority (CEA) has carried out various flexibility  studies  on  the  long-term  impact  of  reduced  technical minimum load requirement of the existing coal-fired Thermal Power Plants (TPPs), in association with Original Equipment Manufacturers

(OEMs) /  National  &  International  partners.  These  studies  indicate that 40%  Minimum  Technical  Load  (MTL)  operation result in accelerate wear of components (particularly rotating components) and also reduces life of key pressure-part along with their efficiency. This impacts the lifespan and efficiency in long-term as:

-  Efficiency degradation;
-  Increase in creep-fatigue;
-  Accelerated corrosion and erosion;
-  Higher risk of fatigue-related failures;
-  Increase in Equivalent Forced Outage Rate (EFOR);
-  Increase in Gross Heat Rate;
-  Higher auxiliary power consumption;
-  Reduced combustion efficiency at low loads.
- (b): The CEA has prepared several remedial & mitigation measures to address such potential impacts on existing coal-fired plants from reduced  technical  minimum  load  (TML)  /  flexible  operation.  These measures aim to ensure operational safety, maintain flame stability &  combustion  quality,  and  minimize  stress  on  boiler  and  turbine systems, thereby reducing equipment damage and efficiency losses at low load. The key measures include retrofits in the existing system as below:
- 
- Implementation of Automation
-  Optimization of control systems
-  Installation of scanner for proper flame detection
-  Installation/ use of steam coil air-preheaters (APH)
-  Improved condition monitoring of boiler, turbine etc.
- 
- Optimisation of Auxiliaries

Further, Generating Companies (GENCOs) have been advised to adopt unit-specific  retrofits  rather  than  a  'one-size-fits-all',  taking  into account plant age, design parameters, coal quality and vintage so as to limit undue stress on plant equipment during flexible operation.

- (c): Ministry  of  Power  has  issued  a  comprehensive  policy  on 07.11.2025 for co-firing of 5-7% blend of bio-mass pellets [including torrefied charcoal made from Municipal Solid Waste (MSW)] in Coal Based Power Plants along with coal, after assessing the technical feasibility.