New Delhi: NTPC has begun installing 5 gigawatt-hours (GWh) of battery storage at its coal-fired power plants, with an estimated investment of about ₹5,000 crore, in a push to reduce renewable energy curtailment. The battery systems are being co-located with thermal units to absorb excess solar and wind power that would otherwise go unused.The Central Electricity Regulatory Commission (CERC) has approved a cost-plus tariff structure for the projects, allowing NTPC to recover its return on equity and fixed charges irrespective of plant utilisation. Combined with a separate rule permitting coal plants to stand down when grid scheduling falls below the 55% technical minimum, the framework gives the company room to manage curtailment while it evaluates a broader rollout.Also read: India's thermal coal imports sink to a 4-year low as green energy reshapes demand"The thermal fleets will have to be supported for a technical minimum because below this, it becomes increasingly infeasible," said Jaikumar Srinivasan, director finance at NTPC. "So, 5 GWh of battery work has already started, and CERC has given its tariff framework for this, supporting this thing."The move reflects a growing challenge for India's power system: renewable energy is increasingly being generated when the grid cannot absorb it. NTPC Green Energy recorded 314 million units of curtailment during the year, along with 135 million units of transmission-related losses, highlighting the scale of clean energy going unused.