The Delhi Electricity Regulatory Commission (DERC) has approved the power sale agreement (PSA) between BSES Yamuna Power (BYPL) and Solar Energy Corporation of India (SECI) for the procurement of 500 MW solar projects with a 250 MW/1,000 MWh energy storage system.

The Commission said that the trading margin will be decided between the two parties.

Background

SECI floated a tender to select solar project developers to set up 2 GW of interstate transmission system (ISTS)-connected solar projects, with 1,000 MW/4,000 MWh energy storage systems, under Tranche XVII.

Five companies were awarded a cumulative capacity of 2,000 MW of solar projects with 1,000 MW/4,000 MWh.

NTPC Renewable Energy won 500 MW, Sembcorp Green Infra won 150 MW, Solarcraft Power India 7 won 150 MW, and Hero Solar Energy won 270 MW, at a tariff of ₹3.52 (~$0.039)/kWh. Reliance NU Suntech won 930 MW at a tariff of ₹3.53 (~$0.0394)/kWh.

The petitioner, BYPL, agreed to offtake 500 MW solar with 250 MW/1000 MWh ESS at the discovered tariffs of ₹3.52 (~$0.039)/kWh and ₹3.53 (~$0.0394)/kWh.

In February 2025, SECI shared the draft PPA and PSA with BYPL, and in March 2025, BYPL entered into a PSA with SECI.

The petitioner submitted that it had approached the CERC to approve the tariffs determined for SECI’s 2 GW of solar projects with 1,000 MW/4,000 MWh ESS.

SECI also signed a PPA with Reliance NU Suntech for 230 MW and with Hero Solar Energy for 270 MW.

The petitioner approached the Commission seeking approval for the PSA for 500 MW solar projects with 250 MW/1000 MWh ESS.

Commission’s Analysis

The Commission noted that in March 2025, it had granted in-principle approval for the execution of the PSA.

It acknowledged that SECI has also signed PPAs with Reliance NU Suntech for 230 MW and with Hero Solar Energy for 270 MW.

The regulator noted that SECI has already approached CERC seeking the adoption of tariffs and the trading margin for the projects. In an earlier order, the CERC had approved the trading margin agreed to by the trading licensee and the seller.

Approving the PSA, the Commission said if SECI fails to provide an escrow arrangement or an irrevocable, unconditional, and revolving letter of credit, the trading margin will be reduced to ₹0.02 (~$0.0002)/kWh.

Recently, DERC approved the PSA between BSES Rajdhani Power and SECI for the procurement of 1,500 MW of solar power integrated with a 750 MW/3,000 MWh ESS under the ISTS Tranche XVII.

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