Energy Storage in Grids with High Penetration of Variable Generation

The focus of this report is on energy storage for the power grid in support of larger penetration of renewable energy. The emphasis is on energy storage and associated power electronics that are deployed in the grid in order to support utility scale renewable energy projects (wind and solar) by providing services like frequency support, voltage support, ramping support, peak-shaving, load-shifting, transmission deferral, and others. The following applications of energy storage are important, but are beyond the scope of this report: residential, commercial or industrial behind-themeter energy storage. Although most of the content in the report is applicable to the benefits of energy storage deployment in grids with minimal or no renewable energy penetration, that is not the focus of the report; instead, the focus is on grids that have or will soon have high renewable energy penetration.