Borrego Springs Microgrid Grows In Scope

SDG&E’s Borrego Springs microgrid is set to be one of the largest in the US to operate solely on renewable energy.
Published: Mon 02 Mar 2015

San Diego Gas & Electric’s (SDG&E) Borrego Springs microgrid, a pioneering example of a real world microgrid, is set to expand further. [Engerati-Real World Applications for Microgrids and Four Important Lessons From the Borrego Springs Microgrid Pilot]

With a US$4.7 million grant from the California Energy Commission (CEC), the microgrid will be connected to NRG Energy’s 26MW Borrego Solar facility to power the community. In addition the current microgrid will be expanded from serving the approximately 1,000 customers currently to incorporate all 2,800 metered customers who live in Borrego Springs.

“SDG&E is very proud to receive this award from the California Energy Commission,” said James P. Avery, SDG&E’s senior vice president for power supply. “This funding will create a true renewable energy microgrid, one that not only bolsters local electric reliability, but does so by using the cleanest resources available.”

Distributed energy resources

The Borrego Springs microgrid uses advanced technologies, including local power generation, energy storage, and automated switching. The microgrid is connected to the centralized energy grid, but can ‘island’ from the larger grid and function independently during emergencies – as it already has done during several power outages, according to SDG&E.

When connected to the Borrego Solar facility, the intermittency in supply will be handled by the large batteries, which will also store solar power generated during the day for use at night for powering critical loads in the community such as cool zones, gas stations and grocery stores. If the batteries exhaust all their power, the system would access traditional onsite generation. SDG&E will use new computer software to make sure all these transitions happen seamlessly and maintain a consistent flow of power to the community. 

The expansion of the microgrid is expected to be completed by mid-2016. With the ongoing success of the project, SDG&E is currently looking into the benefits of developing microgrids in other locations of the grid.

Borrego solar facility

The Borrego Springs microgrid was developed as a demonstration with support from the US Department of Energy and CEC plus matching funds from SDG&E and other project partners. The Borrego Solar facility came into operation in February 2013 and supplies power to SDG&E under a 25-year power purchase agreement.

The latest round of CEC funding formed part of a competitive solicitation for microgrid and electric vehicle charging projects. The seven microgrid projects and three EV charging projects received a total of US$27.3 million.