Energy storage milestone: PG&E, Tesla begin building 730MWh battery system

Utility-scale battery storage took a
major jump forward this month as Pacific Gas & Electric and Tesla began
construction on a 182.5-MW lithium ion system in Monterey County, California.

PG&E will own the facility at
its substation in Moss Landing, but the design, construction and maintenance
operations will be joint effort both by the San Francisco-based utility and the
battery and EV manufacturing giant. Once completed, the partners say, Moss
Landing will be the largest utility-owned, li-ion battery energy storage system
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.”

It includes installation of 256 Tesla Megapack battery units on 33 concrete slabs. The Megapack, which was launched by the company last year and is being made at the Tesla Gigafactory1 in Nevada (pictured), can store up to 3 MWh of electricity per unit.

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 kilovolt (kv) electric transmission system.

The BESS will have the capacity to
store and dispatch up to 730 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-GWh total.

Moss Landing BESS will participate
in the California Independent System Operator (CAISO) markets, providing energy
and ancillary service–such as serving as an operating reserve that can quickly
be dispatched to ensure there is sufficient generation to meet load — to the
CAISO-controlled grid.

“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,” said Mark
Rothleder, vice president, Market Quality & California Regulatory Affairs,
CAISO.

In February 2017, PG&E deployed
its first lithium-ion energy storage system, featuring Tesla Powerpack
technology, at its Browns Valley substation (approximately 50 miles north of
Sacramento).

As of May 2020, PG&E has
awarded contracts for battery energy storage projects totaling more than 1,000
MW capacity to be deployed throughout its service area through 2023.
Third-party owned projects include a transmission-connected 300 MW BESS (also
to be located in Moss Landing), a transmission-connected 75 MW BESS located
near the city of Morgan Hill, Calif, and a 2 MW BESS at PG&E’s Gonzales
substation in the Salinas Valley. PG&E-owned projects include a 20 MW BESS
located at PG&E’s Llagas substation in Gilroy, Calif.

Up to 50 PG&E employees and
contractors will construct the system, and all COVID-19 safety protocols
including a daily health check, physical distancing, and wearing face coverings
will be followed. The BESS was approved by the California Public Utilities
Commission in November 2018 and by the Monterey County Planning commission in
February 2020.

CAISO serves about 80 percent of California and a small part of
Nevada. California state leaders are mandating 100 percent clean energy
generation by 2045, including 33 percent by the end of this year.

Energy Storage backers say that utility-scale batteries can
smooth out the so-called “duck curve” effect of greatest solar penetration
during the day when demand is relatively low, but solar generation drops as
residential demand rises in the evening. California is the nation’s leading
solar energy state, with more than 27,400 MW installed capacity as of last
year, according to the Solar Energy Industries Association.