The power ministry has allowed renewable energy (RE) producers to use electricity curtailed under temporary general network access (T-GNA) to charge additional co-located battery energy storage systems (BESS) and sell the stored power, the Economic Times reported on Saturday.

A no-objection certificate (NOC) from the procurer will not be required under the existing power sale agreement (PSA). The ministry, in a letter dated August 27, clarified that the stored electricity can be sold to any entity through power exchanges or other arrangements.

"To facilitate optimum utilisation of renewable energy generation, it is hereby clarified that RE projects, awarded under the applicable bidding guidelines, may utilise the renewable energy curtailed under T-GNA for charging an additional co-located BESS, not covered under the existing PPA/PSA (power purchase agreement/power sale agreements," the ministry said, according to the ET report.  The clarification follows representations from developers seeking an enabling clarification on the issue.

Why were developers seeking permission to use curtailed power?

In a representation made in June, the National Solar Energy Federation of India (NSEFI) said around 90 per cent of the power scheduled under T-GNA in the northern region was being curtailed. The association had also made a case for allowing the arrangement, saying a merchant BESS would constitute a new element and would not form part of the contracted project configuration under the power purchase agreement (PPA).

Since the PPAs did not explicitly provide for such an arrangement, member developers had approached renewable energy development agencies, including the Solar Energy Corporation of India (SECI) and NTPC, seeking project-specific NOCs. These approvals were sought to allow developers to use curtailed electricity to charge merchant BESS and subsequently sell the stored energy at their discretion.

How will the move benefit renewable energy developers?

The power ministry’s decision will provide relief to renewable energy developers by allowing them to monetise electricity that would otherwise be curtailed under T-GNA. Developers can store the curtailed power in separately deployed, co-located battery energy storage systems (BESS) and sell the stored electricity independently. The additional BESS must not be covered under the project’s existing power purchase agreement (PPA) or power sale agreement (PSA).

The clarification is aimed at ensuring optimum utilisation of renewable energy generation, the power ministry said. T-GNA allows power generators to temporarily access the interstate transmission system, but transmission constraints can result in generation being curtailed, meaning the electricity produced cannot be evacuated.