SDG&E wins approval for cost recovery of air station microgrid services

Nov. 30, 2022
Marine Corps Air Station (MCAS) Miramar helped the utility last summer when the grid was under strain.

Marine Corps Air Station (MCAS) Miramar, whose microgrid serves as a model on several fronts, scored another win with California regulators’ approval of its deal to sell services to San Diego Gas & Electric (SDG&E).

The California Public Utilities Commission (CPUC) ruling gives the utility permission to recover costs from ratepayers for power secured from the air station’s microgrid.

SDG&E struck the agreement with the air station out of concern that it would come up short on power last summer if the grid were under strain — which did happen.

Under the agreement, the utility pays MCAS Miramar for providing 6 MW of generation to the grid during times of emergency.

The deal is significant to the microgrid industry because it puts a monetary value on microgrid use to help avert a grid crisis. Microgrid advocates see it as offering valuable information for regulators elsewhere that are determining how to pay microgrids when they bolster the grid — a microgrid benefit that is increasingly coming to the fore but is inconsistently monetized throughout the US.

Details of agreement

In a Nov. 17 resolution, the CPUC approved the agreement between SDG&E and MCAS Miramar, which ran from July 1 through Oct. 31. It gave the utility the ability to call upon MCAS Miramar up to five times per calendar month from 4 p.m. – 9 p.m. During that time, payment could not exceed $267,840, according to the resolution.

The commission instructed SDG&E to track the costs and true them up at the end of the year, so that they can be included in electric rates with the utilities’ annual consolidated filing.

California has other programs to pay independent generators for emergency use, including its Electric Load Reliability Program and the California State Emergency Program.

MCAS Miramar’s operational characteristics blocked its participation in those programs.

The utility and air station inked a similar deal in 2021, but it was never acted upon.

How the air station helped the grid

However, Microgrid Knowledge reported that this year MCAS Miramar responded to a statewide flex alert on Aug. 17 to relieve demand on the grid.

“This is a first-of-a-kind and one of the most innovative things we have done,” said MCAS Miramar Public Works Officer Cmdr. Jon Angle, following the event.

A few weeks later, the utility made a number of load reduction requests that MCAS Miramar also responded to. 

In its decision, the CPUC said that MCAS Miramar’s performance should be evaluated should the agreement be extended or revised for future years.

Military microgrid leadership

MCAS Miramar has a sophisticated microgrid that can fully power the 23,000-acre air base for up to 21 days. Completed in March 2021 by Schneider Electric and Black & Veatch, it uses a variety of resources, including photovoltaic and solar thermal energy, batteries, methane, natural gas and diesel.

The US military has been a strong proponent of microgrids. In February, the Army announced it would build a microgrid at each of its bases worldwide by 2035. In May, the Navy and Marine Corps made similar commitments.

To learn more about MCAS Miramar’s microgrid, listen to the air station’s Mick Wasco in this video discussion: Why the Electric Grid is No Longer Enough.

About the Author

Elisa Wood | Editor-in-Chief

Elisa Wood is the editor and founder of She is co-founder and former editor of Microgrid Knowledge.

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