Pacific Gas and Electric (PG&E) and Tesla have started constructing a 182.5-megawatt (MW) lithium-ion battery energy storage system (BESS) at PG&E’s Moss Landing electric substation in Monterey County.
The system will be designed, constructed, maintained by PG&E and Tesla, and owned and operated by PG&E. Construction will proceed until the beginning of next year. PG&E plans to energize the system in early 2021 and to have it completely 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.
“The scale, purpose and flexibility of the Moss Landing Megapack system make it a landmark in the development and deployment of utility-scale batteries.”Fong Wan, senior vice president, energy policy and procurement, PG&E.
PG&E estimates that the Moss Landing BESS would save more than $100 million over the project’s 20-year existence, compared with the expected local capacity requirements and associated procurement costs that would have been required in the absence of the BESS.
It comprises 256 Tesla Megapack battery units mounted on 33 concrete slabs. Each unit holds, in a single cabinet, batteries and power conversion equipment. Transformers and switchgears will also be mounted along with the Megapacks to link the energy stored in the batteries to the electric transmission network of 115 kilovolts (kv).
The BESS will have the ability to store and transmit up to 730 megawatt hours (MWh) of energy to the electrical grid for up to four hours during times of high demand at a maximum rate of 182.5 MW. PG&E ‘s deal with Tesla provides an upsize option that will boost the system’s efficiency up to six hours or a total of 1.1-Gigawatt-hour (GWh).
“Energy storage is critical in achieving California’s clean energy goals, and the California ISO looks forward to working with PG&E in advancing its storage projects.”Mark Rothleder, vice president, market quality & California Regulatory Affairs, CAISO.