Tesla hits another gigantic energy storage agreement in California

Late last week, California-based Pacific Gas and Electric Company (PG & E) asked the state to approve four lithium-ion battery storage projects. ion. Three of them would be owned and operated by a third party, and one, built by Tesla, would be owned and operated by PG & E.

One of the projects – led by the company. Vistra energy (which recently merged with Dynegy) – could become the first installation of lithium-ion batteries at the scale of the grid to store more than a gigawatt hour of energy.

Tesla's project is also huge. It would provide 730 MWh of energy, but Tesla's contract with PG & E suggests that the utility could choose to increase the battery size to 1.1 GWh.

The Tesla installation is expected to discharge 182.5 MW for 4 hours (hence the number 730MWh). But the contract could be increased to a 6-hour discharge duration, which would result in just under 1.1 GWh of PG & E-owned storage. For comparison, last year, Tesla realized the largest lithium-ion battery installation in the world in South Australia. This battery system has accumulated 100 MW / 129 MWh of storage

Storage of this size allows the utility to add more renewable energy because if the wind speed drops or if the night cloud cover in the sun, a battery can come into contact with the rest.

The Tesla / PG & E battery would be located in the Moss Landing substation in California, near Monterey Bay (and home to the Monterey Bay Aquarium Research Center). PG & E has indicated that it expects the battery to be completed by 2019, pending the approval of the California Public Utilities Commission (CPUC).

Vistra / Dynegy also proposed to build a 300 MW battery that can be discharged for four hours. At 1.2 GWh, the battery would be among the largest in the world and would also be located on the Moss Landing site. A press release from the company anticipates that the facility will be completed by the end of 2020. The project would be supported by a 20-year contract with PG & E to buy energy from Vistra.

A spokeswoman for Vistra said yet selected a supplier at the source of its batteries. The project would utilize two existing interconnection points at Moss Landing to connect to the grid, as well as an "existing turbine building on the site to house the batteries."

The other two projects are smaller and include a 75 MW / 300 MWh battery installation from a company called Hummingbird Energy Storage LLC, as well as an aggregation project from Micronoc Inc., which will implement 10 MW / 40 MWh of batteries in commercial locations.

These projects depend on the approval of the CPUC to go forward. PG & E to speed up its solicitation of battery storage in January, so the proposals are not too surprising. A response from the CPUC is expected in 90 days.