Energy storage companies “have suffered significant and detrimental harm” from changes to rules governing the frequency regulation market in US regional transmission organisation (RTO) PJM Interconnection’s service area, the Energy Storage Association has said.

Swiss Green Electricity Management Group (SGEM), an investor in energy storage projects, has announced a 20MW / 10MWh battery storage system for PJM Interconnection’s frequency regulation market, to be supplied and built by Leclanché.

Deploying battery storage at grid level is relatively uncharted territory, but a number of pioneers’ projects are now in the ground. Patrick Leslie and colleagues at RES, which built some of the first wave of storage projects, teases out the key technology, finance and regulatory lessons the industry can learn from these early experiences.