Electrical equipment energy storage and disconnection

What is electrical energy storage (EES)?

Electrical Energy Storage, EES, is one of the key technologies in the areas covered by the IEC. EES techniques have shown unique capabilities in coping with some critical characteristics of electricity, for example hourly variations in demand and price.

Are energy storage systems safe?

The emergence of energy storage systems (ESSs), due to production from alternative energies such as wind and solar installations, has driven the need for installation requirements within the National Electrical Code (NEC) for the safe installation of these energy storage systems.

What is an ESS equipment disconnect?

An ESS equipment disconnect should be able to de-energize the equipment from all power sources and monitor that the system stays de-energized as long as needed. Source disconnects isolate power production equipment from the remainder of the premise wiring.

What is an electrochemical energy storage system?

Electrochemical energy storage systems Part III of Article 706 applies to energy storage systems that comprise sealed and non-sealed cells, batteries, or system modules that comprise multiple sealed cells or batteries that are not components within a listed product.

Where fused disconnecting means are used?

Where fused disconnecting means are used, the line terminals of the disconnecting means shall be connected toward the energy storage system terminals. 4. Disconnecting means shall be permitted to be installed in energy storage system enclosures where explosive atmospheres can exist if listed for hazardous locations.

Where are equipment disconnects located?

Equipment disconnects are usually located on or adjacent to the equipment they disconnect and need to be lockable in the open position in accordance with 2017 NEC 705.22 and 2020 NEC 706.15.