As part of an EPRI collaborative research and development (R&D) project to evaluate the performance and reliability of a variety of grid-connected Li-ion battery technologies, San Diego Gas & Electric (SDG&E) installed a 50 kW / 82 kWh Greensmith lithium-iron-phosphate distributed energy storage system (DESS) at the utility’s test facility. For this overarching collaborative demonstration, EPRI’s Energy Storage Program (P94) and Distributed Renewables Program (P174) are working in partnership with select utility members to investigate PV-battery integration capabilities. Serving as a “host” utility to EPRI’s supplemental demonstration initiative, SDG&E installed a Greensmith DESS in a grid-connected configuration in June 2011 and has been conducting operating evaluations of the unit over the past 6 months.

Testing and operating evaluation conducted by SDG&E encompasses exercising the DESS’s various modes of operation, which include:
- Constant power charge/discharge schedule;
- Peak shaving; and
- PV smoothing.

Lithium-ion Battery