What are the requirements for energy storage systems?

Energy storage systems shall be installed in accordance with NFPA 70. Inverters shall be listed and labeled in accordance with UL 1741 or provided as part of the UL 9540 listing. Systems connected to the utility grid shall use inverters listed for utility interaction.

What is the maximum energy rating per ESS unit?

The maximum energy rating per ESS unit is 20 kWh. The maximum kWh capacity per location is also specified—80 kWh when located in garages, accessory structures, and outdoors and 40 kWh in utility closets or storage spaces. For storage capacities that exceed these limits, non-residential requirements come into play (NFPA 855 Chapters 4-9).

Are energy storage systems required in the 2015 NFPA 1?

While the 2015 versions of the IFC and NFPA 1 do contain some requirements for energy storage systems, they are few compared to the 2018 and 2021 versions. The ESS requirements in the 2018 version, while certainly more restrictive than the 2015 version, are relatively modest.

What are the ESS location requirements?

ESS location requirements are detailed for areas including garages, accessory structures, utility closets, and outdoors. ESS installed outdoors may not be within 3-feet of doors and windows. Note that ESS units may not be installed in living areas or bedrooms. The maximum energy rating per ESS unit is 20 kWh.

Are there any problems with energy storage?

There have also been issues in the U.S. residential energy storage sector. For example, after five reported fires stemming from its RESU10 battery units, LG Chem issued product recalls in December of 2020 and again in August 2021. According to the Consumer Product Safety Commission, these fires resulted in property damage and one injury.

What is the minimum spacing between ESS units?

A minimum spacing of 3 feet is required between ESS units unless 9540A testing allows for closer spacing. ESS location requirements are detailed for areas including garages, accessory structures, utility closets, and outdoors. ESS installed outdoors may not be within 3-feet of doors and windows.