The Central Electricity Authority (CEA) has proposed that batteries deployed under battery energy storage systems (BESS) should be designed with a two-fault tolerance mechanism to check for accidents and overheating.

This is part of the Draft CEA (Measures relating to Safety and Electric Supply) (First Amendment) Regulations, 2025.

“Battery systems shall be designed with two-fault tolerance to prevent catastrophic failures under all conditions, including but not limited to overcharge, over-discharge, short circuit, and operation outside specified temperature limits,” the draft said.

The Authority added that two-fault tolerance refers to the system’s ability to continue to operate safely or shut down even after two independent faults have occurred.

Safety requirements

Through these proposals, the government wants to address the hazards in BESS such as overcharge, short circuit, etc.

Welcoming the development, Arindam Ghosh, Partner Power Advisory at Nangia & Co, said the comprehensive safety regulations for BESS demonstrates a proactive approach by the government.

The general safety consideration includes proposals like chargers used for BESS should be designed for the chemistry of the battery to be charged.

Besides, fire and explosion protection at cell level, module level, container level and site specific installation level shall be as per the relevant standard, it said.

The battery management system (BMS) should monitor and record voltage, temperature, current, and thermal runway at cell level and module level, the draft added.

The BMS should also automatically stop charging and discharging the battery when the temperature readings exceed manufacturer’s recommended values, the CEA has proposed.

Similarly, the power conversion system (PCS) should be capable of fully automatic and unattended operation, including synchronising with the grid or electric power system, seamless paralleling and disconnecting from the grid or electric power system.

It should include self-protective and diagnostic features to protect itself from damage in the event of component failure and abnormal operating parameters.

Comprehensive regulations

Ghosh emphasised that as BESS deployments scale up, large volumes of batteries will reach end-of-life. International frameworks, including the EU Regulation 2023/1542, highlight the importance of managing safety across the entire battery life cycle.

This safety framework can be expanded to include a lifecycle-based approach that covers manufacturing, transport, installation, maintenance, and decommissioning of BESS, he suggested.

From a practical implementation perspective, it may be more appropriate to introduce tiered safety provisions that distinguish between large, grid-scale containerized BESS installations and smaller behind-the-meter systems, such as those deployed in residential or commercial premises, he added.

This will not only reduce the burden on small-scale developers and rooftop solar developers but also allow Discoms to focus resources on high-risk installations, Ghosh explained.

He emphasised that the draft lacks provisions for mandatory reporting of safety incidents, such as battery fires, explosions, or electrolyte leakage.

“It is recommended that an incident reporting mechanism be instituted under CEA where BESS owners or operators may be mandated to report defined classes of incidents to the designated safety authority within a stipulated time frame. These reports can form the basis for regulatory advisories, public safety bulletins, and updates to design or maintenance standards,” Ghosh stressed.

Published on June 25, 2025