Folsom, Calif: San Diego Gas & Electric (SDGE) announced a vanadium redox battery storage pilot project in late April, in coordination with Sumitomo Electric, stemming from a partnership between Japan’s New Energy and Industrial Technology Development Organization (NEDO) and the California Governor’s Office of Business and Economic Development (GO-Biz). The California Independent System Operator says the project will make CAISO one of the nation’s first wholesale power markets to connect flow technology batteries to its grid.
The four-year pilot project is intended to test and evaluate the best ways to manage and maximize new storage technology on the grid, demonstrate the economics of flow batteries in the commercial wholesale market, provide flexibility, and integrate growing amounts of renewable energy onto the system.
In 2015, NEDO signed an agreement with the GO-Biz to test flow battery performance in a demonstration setting. NEDO then contracted with Sumitomo Electric to implement the project. The battery was installed at an SDG&E substation, where it has undergone testing and fine-tuning for reliability and performance, before starting participation in the ISO wholesale electricity markets in December 2018.
The flow battery will provide 2 megawatts and 8 megawatt hours of energy, enough to power the equivalent of about 1,000 homes for up to four hours.
Storage is seen as a vital resource to California meeting its target of getting 100 percent of its electricity from zero-carbon resources by 2045.
Renewables, especially in the form of solar panels, are being added at such a quick pace that ISO is now managing an oversupply of solar power in the middle of the day, and a subsequent drop-off in solar production at the end of day, when electricity demand is spiking. The trend is causing the system to curtail solar generation during times of oversupply, and creating a need for fast-starting resources to fill demand in the evening, often natural gas plants.
With more storage capability on the system, the solar energy production could be captured and used later in the day, smoothing out the wide fluctuations between supply and demand, and allowing for more renewables to be used by end-use consumers.