The National Electrical Manufacturers Association (NEMA) published NEMA ESS 1-2019 Protocol for Uniformly Measuring and Expressing the Performance of Electrical Energy Storage Systems. This Standard provides a set of best practices for characterizing electrical energy storage systems (ESSs) and measuring and reporting their performance.

An ESS includes a storage device, battery management system, and any power conversion systems installed with the storage device. This Standard treats all systems the same concerning technology, size, and rating.

"ESS 1 serves as a basis for assessing how an ESS will perform with respect to key performance attributes relevant to different applications," said Brian Marchionini, Senior Program Manager, NEMA. "It is intended to provide a valid and accurate basis for the comparison of different ESSs. This Standard will enable more informed decision-making in the selection of ESSs for various stationary applications."

NEMA ESS 1-2019 is available in hard copy and as an electronic download for $150 on the NEMA website.