Energy Storage

Energy Storage Project Announced to Serve California Grid

An energy storage project in Southern California will provide resource adequacy (RA) and ancillary services to the state’s power grid, adding more reliability and resiliency for electricity in the California Independent System Operator (CAISO) market.

LS Energy Solutions (LS-ES), which provides grid-connected energy storage solutions, on September 7 said it would deploy 200 MW/400 MWh of storage capacity at the Big Rock project in Imperial County. LS-ES officials said the installation will use 137 AiON-ESS units, and will be the largest to date for the Charlotte, North Carolina-based company.

Gore Street Energy Storage Fund (GSF) is developing the project. The companies made the announcement Thursday just days ahead of the RE+ clean energy trade show in Las Vegas, Nevada, which runs September 11 to 14. An AiON-ESS unit will be on display at the show, with attendees able to walk around an AiON-ESS container. POWER, which also is participating in RE+, is a media partner for the event.

DC and AC Components

The companies said the all-in-one AiON-ESS containers at Big Rock will be able to store energy for a two-hour duration. Direct current (DC) and alternating current (AC) components will be integrated inside each container, as with other AiON-ESS Energy Series installations, and will provide AC output ready to be fed into medium-voltage transformers. Each unit has a power rating of 1.5 MW and can store 3.5 MWh. Along with tier-1 lithium-ion batteries, the 137 containers include more than 1,300 of LS-ES’s modular 140 kVA AiON-SIS string inverters.

The Big Rock site will be part of a CAISO energy storage fleet already served by more than 5.6 GW of capacity. Officials said Big Rock will be operated at 100 MW of deliverability to supply 400 MWh and meet the four-hour discharge needs of an RA contract. The project, managed by UK-based Gore Street Capital, will help CAISO maintain supply and demand for electricity in real time.

An LS Energy Solutions AiON-ESS Energy Series unit of the type that will be installed at the Big Rock energy storage project in Imperial County, California, a site developed by Gore Street Energy Storage Fund. Source: LS Energy Solutions

“The Big Rock energy storage system is a major step forward for Gore Street Energy Storage Fund and for LS Energy Solutions. GSF has amassed an impressive energy storage portfolio in the UK, mainland Europe and the U.S., with assets in Texas and California. We are thrilled to partner with the company on its first large-scale system in the U.S.,” said Steve Fludder, CEO and President of LS Energy Solutions. “We are also very grateful for our partnership with Avantus and look forward to working with them during project completion.”

Site Acquired Earlier This Year

GSF acquired the Big Rock site in February 2023 from Avantus, the California-based group formerly known as 8minute Solar Energy. Avantus which will continue to provide administrative and development services for the installation. Alex O’Cinneide, CEO of Gore Street Capital, said, “The Big Rock project marks GSF’s most recent acquisition, and the company’s biggest to date. As the investment manager, we are thrilled to have the project in our portfolio under management and to work with LS Energy Solutions in bringing the project to fruition.”

O’Cinneide continued: “As the company’s first project in California, Big Rock will be an important addition to the CAISO grid, helping to deliver stability to a rapidly decarbonizing energy system. Our in-house technical team is looking forward to working with LS-ES and its containerized units as construction at Big Rock progresses, and we’re excited to participate in the CAISO market.”

LS-ES, In addition to supplying AiON-ESS containers, also expects to provide commissioning support and operational services including extended warranty, preventative maintenance, capacity maintenance, and system remote monitoring for the life of the Big Rock project.

Construction of the Imperial County installation is expected to begin soon, with commercial operation expected in the second half of 2024.

Darrell Proctor is a senior associate editor for POWER (@POWERmagazine).

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