Tesla and PG&E Break Ground on 182.5 MW BESS System in California

Tesla and PG&E have announced that construction work has begun on the 182.5 MW lithium-ion BESS at PG&E’s electric substation in Moss Landing, California.

Tesla and Pacific Gas and Electric Company (PG&E) have announced that construction work has begun on the 182.5-megawatt (MW) lithium-ion battery energy storage system (BESS) at PG&E’s electric substation in Moss Landing in Monterey County, California.

The system will be designed, constructed, and maintained by PG&E and Tesla, and will be owned and operated by PG&E. Construction is expected to continue into early next year. PG&E aims to have the system energised in early 2021 and fully operational in the second quarter of 2021. Once operational, the Moss Landing substation system will be one of the largest utility-owned, lithium-ion battery energy storage systems in the world.

“Battery energy storage plays an integral role in enhancing overall electric grid efficiency and reliability, integrating renewable resources while reducing reliance on fossil fuel generation. It can serve as an alternative to more expensive, traditional wires solutions, resulting in lower overall costs for our customers,” said Fong Wan, senior vice president, Energy Policy and Procurement, PG&E. “The scale, purpose and flexibility of the Moss Landing Megapack system make it a landmark in the development and deployment of utility-scale batteries.”

PG&E forecasts the Moss Landing BESS will save more than USD 100 million over the 20-year life of the project when compared to the forecasted local capacity requirements and associated procurement costs that would have been necessary in absence of the BESS.

The BESS was approved by the California Public Utilities Commission in November 2018 and by the Monterey County Planning commission in February 2020.

The project includes the installation of 256 Tesla Megapack battery units on 33 concrete slabs. Each unit houses batteries and power conversion equipment in a single cabinet. Transformers and switchgears will also be installed along with the Megapacks to connect energy stored in the batteries with the 115 kilovolts (kv) electric transmission system.

The BESS will have the capacity to store and dispatch up to 730 megawatt-hours (MWh) of energy to the electrical grid at a maximum rate of 182.5 MW for up to four hours during periods of high demand. PG&E’s agreement with Tesla contains an upsize option that can increase the capacity of the system up to six hours or 1.1-Gigawatt hour (GWh) total.

California’s Energy Storage Decision (AB 2514), passed by the legislature in 2013, requires investor-owned utilities to provide 1,325 MW of operational energy storage capacity by 2024. PG&E’s share is 580 MW, and the Moss Landing substation BESS is one of many storage projects the company intends to deploy over the next few years.