Infrastructure & data centers

Battery Energy Storage System (BESS)

Battery installation providing energy storage and discharge to stabilise supply and support critical loads.

Definition

A battery energy storage system stores electrical energy to discharge it when needed, ensuring supply continuity, peak shaving and the integration of intermittent renewable sources. In data centres, it complements or gradually replaces traditional uninterruptible power supplies and generators to support critical loads during a grid outage. Massive recourse to battery storage, often lithium-based, introduces a specific fire peril, however: the thermal runaway of a cell can propagate and trigger a loss that is hard to extinguish, releasing toxic gases. For insurance, the BESS has become an underwriting subject in its own right, at the crossroads of fire risk, environmental risk and business interruption risk. The novelty of large installations and the rapid evolution of battery chemistries maintain high uncertainty over the real frequency and severity of losses.

Example

The thermal runaway of a lithium battery module in a storage system can cause a long-duration fire, posing a novel fire underwriting challenge.

Related terms
Also known as

BESS, stockage par batteries, battery energy storage system