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Successful Project Completion

SDG&E and Sumitomo Electric Complete Zero-Emissions Microgrid Pilot Project, Helping Advance California’s Climate Goals


Redox Flow Batteries in San Diego

The New Energy and Industrial Technology Development Organization (“NEDO”) and Sumitomo Electric Industries, Ltd. (“Sumitomo Electric”) have completed a demonstration project in the U.S. State of California to improve the power quality of the grid, and have successfully achieved the major deliverables such as establishment of a microgrid on a commercial power distribution network inclusive of 66 customers, operation of a large-scale stationary storage battery, the Redox Flow Battery (RF Battery), and multi-use operation in both normal and emergency situations.


The system makes it possible to earn revenue through electricity market transactions during normal operations, in addition to providing power to blackout areas or the areas that outages are assumed, as an independent power source, during an emergency such as natural disasters and planned outages. It is the first time in the U.S. and Japan that a microgrid has been operated on a commercial distribution network with the storage batteries as the main power source, bracing for a power outage.

The results of this demonstration project could be applicable to the cases with high potential demand both in Japan and abroad in the future, such as microgrids with solar and wind power facilities constructed for off-grid areas and 100% renewable energy supply is required for the islands where the transportation cost of power generator fuels is expensive.


The project was the result of an international public-private partnership between NEDO, GO-Biz, SDG&E, and Sumitomo Electric.


Read the full report in Japanese

Link to SDG&E website

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