The Central Electricity Authority (CEA) has issued draft guidelines relating to the safety and electric supply of battery energy storage systems (BESS).

Stakeholders can submit their comments and suggestions by July 20, 2025.

The chargers used for battery energy storage systems must be specifically designed to match the battery chemistry. The battery system must be built with two-fault tolerance, ensuring it can either continue safe operation or shut down safely even after two separate faults occur. This protection must apply under all conditions, including overcharge, over-discharge, short circuit, and operation outside the defined temperature range.

Fire and explosion safety measures must be implemented at the cell, module, container, and site installation levels. The battery management system must monitor and record voltage, temperature, current, and thermal runaway at both cell and module levels. Visual and audio alarms must activate when any monitored parameter exceeds the range specified by the original equipment manufacturer. The system must also automatically stop charging and discharging if the temperature crosses the manufacturer’s recommended limits.

The power conversion system must support fully automatic and unattended operation, including grid synchronization, seamless connection, and disconnection from the grid. It must feature self-protection and diagnostic capabilities to safeguard against component failure or abnormal operating conditions.

Coolant lines must be routed and secured to prevent leaks near live electrical parts. Any failure in the dielectric fluid cooling system, including issues in the cooling lines, must not lead to leakage that could cause cell short circuits or create hazardous conditions inside the battery pack.

Battery Container

The battery container must be designed to be explosion-proof and equipped with a forced ventilation system along with automated louvers to safely release flammable gases and maintain internal pressure within safe limits. Ingress protection must comply with applicable standards. The walk-in arrangement of the battery energy storage system, including entry and exit points, must also adhere to the relevant standards.

Equipment Location

Battery containers must be placed at a minimum distance of 7.5 meters from the nearest exterior wall or roof overhang. If this distance cannot be maintained, large-scale fire testing must be carried out to confirm the safety of the installation. In areas where the battery energy storage system is located within a densely populated urban zone or near critical infrastructure, appropriate measures must be taken to reduce noise levels.

A minimum distance of 3 meters must be maintained between two battery containers. If this is not feasible, large-scale fire testing must be performed. In such cases, the external wall of each container must have a fire-resistance rating of at least two hours.

The Central Transmission Utility of India had earlier proposed that a minimum of 3 acres must be considered the benchmark for setting up a 100 MWh BESS project.

Ventilation

Each battery container must be equipped with adequate ventilation and cooling systems to prevent overheating. A suitable mechanism must be in place to control the concentration of flammable substances within the enclosure in line with the relevant Indian standards. If the mechanical ventilation system fails, the battery system must automatically shut down to ensure the concentration of flammable materials remains within safe limits.

Hazard Detection and Suppression

The battery energy storage system must be equipped with hazard detection systems capable of identifying smoke, gas, heat, and flame. These systems must be actively monitored. Any battery container with a capacity of 200 kWh or more must be fitted with an automatic water-based fire suppression system that complies with the applicable standard. All components of this fire suppression system must be protected from environmental exposure and unauthorized access while remaining easily accessible for routine inspection and maintenance.

Other measures

For batteries using acidic or basic aqueous electrolytes in liquid form, appropriate containment must be provided to manage electrolyte spills. Enclosed working areas must have a separate emergency lighting source that activates automatically, in line with the applicable standard.

Battery energy storage system installations must be enclosed with fencing of at least 1.8 meters in height to prevent unauthorized access. Surveillance systems, including CCTV, motion sensors, break-glass detectors, and alarms connected to a monitoring and response setup, must be installed at strategic locations.

If a safety issue or battery anomaly is detected, the affected part of the battery system must shut down within a pre-set time frame. Manual emergency stop mechanisms, including buttons or switches, must be installed in clearly visible and easily accessible locations.

An independent third-party fire safety audit must be carried out for each installation, as outlined in the standard operating procedure to be issued by the CEA within three months from the notification of these regulations.

The battery energy storage system owner must submit this fire safety audit report to the Electrical Inspector during the inspection process. The appropriate government must also ensure that fire safety personnel receive training tailored to address the unique fire risks associated with battery energy storage systems.

The Directorate General of Fire Safety will issue the training guidelines within three months from the notification of these regulations.

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