Tesla plugs big batteries into PG&E’s electric grid
A row of tall white boxes by the side of a Sierra foothills highway could represent a key piece of California’s future electric grid.
Made by Tesla, the boxes contain thousands of battery cells — the same cells that power Tesla’s luxury cars. But at this installation, at a Pacific Gas and Electric Co. substation in Browns Valley (Yuba County), the batteries soak up electricity whenever it’s cheap and feed it back onto the grid when demand hits its daily peak.
The project, operational since the start of the month, represents a collaboration between PG&E and Tesla on one of California’s biggest energy goals: storage.
As part of the fight against climate change, California is adding solar power at a rapid clip, at times flooding the grid with more renewable power than it needs. That flood ebbs by late afternoon, when the demand for electricity hits its peak.
So state regulators have ordered utilities to invest in projects to store energy when it’s plentiful and use it when it’s needed most.
Big battery packs can take the place of peaker plants, small fossil-fuel power plants that may only run for a few hours a day. The Browns Valley project may also help PG&E avoid upgrading that substation to handle rising electricity demand in the area.
And batteries can be installed far quicker than the years it takes to design and build a peaker plant. Work on the Browns Valley project began in June. The batteries were built in Tesla’s Gigafactory near Reno.
“It’s pretty modular — you can scale up and down as you need,” said Mike Della Penna, PG&E’s project manager for the Browns Valley installation.
Last month, Tesla opened an even larger lithium-ion facility for Southern California Edison in San Bernardino County. Another Tesla battery installation in Hawaii stores power from solar panels on Kauai.
The PG&E project, designed and installed by Cupertino Electric, includes 22 Tesla Powerpack batteries, which together can store half a megawatt of electricity. That’s roughly enough to power 380 typical homes at any given moment. The batteries can discharge at full power for four hours.
Both PG&E and Tesla declined to reveal the project’s cost.
But Tesla has big hopes for its battery-storage business, which includes Powerwall batteries that can be installed in homes. The company estimates that one-third of the battery cells produced at its rapidly expanding Gigafactory will go toward stationary storage products, rather than cars.
PG&E has long experience with energy storage. Its Helms Pumped Storage Plant, which opened in 1984, uses water flowing through tunnels between two mountain reservoirs at different elevations to store up to 1,212 megawatts of electricity.
