The Bihar Electricity Regulatory Commission (BERC) has approved a provisional tariff of ₹3.02 (~$0.033)/kWh for Bihar State Power Generation Company’s (BSPGCL) 185 MW Kajra solar project with a 282 MWh battery energy storage system (BESS).

Citing incomplete cost data, the Commission deferred final tariff determination until BSPGCL submitted the audited costs after the project’s full commissioning.

Background

BSPGCL filed a petition with the Commission seeking approval of the levelized tariff for its 185 MW solar plus 282 MWh storage project. The project aims to supply 45.4 MW of power to the state’s distribution companies (DISCOMs) for four hours during peak hours from the storage component, and the balance capacity from the solar project during solar hours.

The petitioner had earlier approached the Commission on behalf of the state DISCOMs: North Bihar Power Distribution Company and South Bihar Power Distribution Company, seeking approval for the procurement of power from the project.

The Commission had granted in-principle approval to procure power from the project at a tariff to be determined by it.

The Kajra solar plus storage project is designed to prioritize storage, using 25% of its daily generated solar power to charge the battery, with the remaining energy injected into the grid in real time. The energy stored in the BESS can be evacuated to the grid separately during non-solar hours to the grid peak time daily.

The power injection from the energy storage system can be varied according to the procurer’s request, subject to system suitability.

The petitioner stated that the solar project is expected to have a 25-year life, while the battery is expected to last 12 years and will need replacement the year after to keep the project running for the full term.

In the latest petition, BSPGCL informed that it had submitted only tentative project cost figures for tariff determination, not audited final cost data.

The petitioner asked the Commission for permission to submit the final project cost details based on the actual expenses incurred up to the commercial operation date (COD). It requested an interim tariff of ₹3.4 (~$0.037)/kWh for the supplied energy till the final determination of the petition. This proposed tariff was 90% of the claimed levelized tariff.

BSPGCL also asked for permission to revise the declared capacity utilization factor once, after the first year of COD, by filing another petition before BERC. It sought permission to approach the Commission at the project’s 13^th year for approval of the actual BESS replacement expenditure.

The petitioner also submitted that the project had already achieved partial commissioning at the 33 kV voltage level. The project had also been synchronized at the 132kV voltage level, with 39.6 MW capacity in an initial commissioning phase and 26.4 MW in a later phase. Power generation from the solar systems had commenced. The storage system had not been commissioned.

Commission’s Analysis

The Commission noted that it could not determine the final levelized tariff because the petitioner had submitted only tentative cost figures, not audited project-specific costs. BERC would require more details to calculate the final tariff.

However, the Commission approved a provisional tariff of ₹3.02 (~$0.033)/kWh to provide the petitioner with cash flow relief. This tariff would apply to the power already being generated and injected into the grid from the commissioned solar capacity.

The provisional tariff would be applicable from the project’s initial date of power injection. The Commission directed the petitioner to approach it later with the required audited project cost data for determining the levelized tariff for the complete project capacity.

Recently, BERC issued a suo motu order determining the generic levelized tariffs for biomass, cogeneration, gasifier, municipal solid waste, and refuse-derived fuel-based renewable energy projects for the financial year 2025–26.

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