California Brownouts Could Be Prevented by Tesla Batteries

The Browns Valley substation located outside Napa Valley now houses 22 refrigerator-sized Tesla Powerpacks that store a total of 0.5 megawatts of power, which is enough to power 1,500 homes for four hours. These batteries--comprising thousands of the same lithium-ion battery cells that power Tesla vehicles--charge when demand is low, and discharge back into the grid when demand at the substation increases, such in evenings when commuters return to their homes, reducing the risk of overloading. 

In addition to keeping air conditioners running during intense heat waves, the project will help PG&E evaluate various storage technologies and their roles in stabilizing the grid. PG&E has implemented battery storage systems at its Vaca-Dixon and Yerba Buena locations, but this is the first location employing Tesla Powerpacks. The system is expected to operate autonomously to "shave peaks" in demand, and as a scalable solution, could also help PG&E avoid future construction upgrades to that substation to handle rising electricity demand as the area grows.

PG&E began construction on the Browns Valley battery installation in June, 2016 with construction company Cupertino Electric, and was brought online last month. However, it could have started earlier had weather been more cooperative, PG&E's Paul Doherty told The Drive. The first results of this project are expected in April or May.

This is the third utility installation in the U.S. for Tesla, which recently dropped "Motors" from its name, representing its push into the energy sector. Last month it opened a 80mw battery storage facility in Southern California, and also provides storage for a solar energy plant in Hawaii.