New Delhi: State-owned NTPC has initiated plans to develop flexible coal-fired thermal power units designed to support grid stability and ensure reliable electricity supply as the share of renewable energy in India’s power mix continues to expand.
The move comes amid growing concerns over the intermittency of renewable energy sources such as solar and wind, which can create challenges in balancing electricity demand and maintaining grid frequency.
NTPC said the rapid growth of renewable energy capacity is helping advance India’s clean energy goals but is also increasing the need for flexible generation assets capable of responding quickly to fluctuations in power demand and renewable energy output.
To address this requirement, the company has invited expressions of interest for sub-critical thermal power units with capacities ranging from 150 MW to 250 MW. These units are expected to operate in a highly flexible manner, including two-shift operations, and function at a minimum technical load of just 25% of installed capacity. Unlike conventional baseload plants, they are intended primarily to provide balancing support rather than run continuously at full capacity.
“Through this initiative, NTPC aims to identify technology providers and engineering, procurement and construction (EPC) partners for developing highly flexible thermal generation solutions, reinforcing its commitment to grid reliability, stability and India’s evolving energy transition needs,” the company said.
NTPC noted that its existing thermal power fleet is currently capable of operating at a minimum technical load of 55% during periods of low demand while also providing critical grid-support services. These include frequency regulation, reserve power management and rapid adjustments in generation to compensate for variations in renewable energy production.
The company pointed out that India currently has limited balancing resources in the form of hydroelectric power, gas-based generation and large-scale energy storage systems. As a result, thermal power plants continue to play a vital role in maintaining a stable and reliable electricity supply.
While solar energy now contributes nearly a quarter of daytime electricity demand, its output remains dependent on weather conditions, seasonal variations and geographical factors. Consequently, thermal power plants are required to complement renewable generation and ensure grid stability, particularly during evening and night-time hours when solar power is unavailable.
Explaining its preference for sub-critical technology, NTPC said operational experience indicates that such units may offer greater flexibility for certain grid-balancing applications than supercritical or ultra-supercritical plants. Their ability to operate efficiently at lower loads and withstand frequent start-stop cycles with lower operational stress makes them well-suited to supporting higher levels of renewable energy integration in the future.
