LS Energy Solutions and Gore Street Energy Storage Fund Partner on 200 MW/400 MWh Energy Storage Project

CHARLOTTE, N.C., Sept. 07, 2023 (GLOBE NEWSWIRE) -- LS Energy Solutions (“LS-ES”), a leading provider of grid-connected energy storage solutions, announced today that the company is deploying 200 MW/400 MWh of energy storage to a site in Southern California. Gore Street Energy Storage Fund (LON: GSF) is developing the Imperial County project, named Big Rock, which will use 137 AiON-ESS units in the largest LS-ES installation yet. The site will provide resource adequacy (RA) and ancillary services to the CAISO market, contributing to a more reliable grid for one of the world’s largest power grids.

The all-in-one AiON-ESS containers at Big Rock can store energy for two-hour duration and, like other AiON-ESS Energy Series installations, integrate DC and AC components inside each container and 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 over 1,300 of LS-ES’s modular 140 kVA AiON-SIS string inverters.

The site will be one of the largest energy storage projects in Imperial County and joins over 5.6 GW of energy storage serving CAISO, California’s grid operator. 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. This management by Gore Street Capital, the Investment Manager of GSF, will contribute to the available capacity and reserves needed by CAISO to maintain supply and demand in real time.

“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 US, with assets in Texas and California. We are thrilled to partner with the Company on its first large scale system in the US,” 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.”

Gore Street Energy Storage Fund acquired the Big Rock site in February 2023 from Avantus, which will continue to provide administrative and development services for the installation. Big Rock joins other energy storage investments by the Gore Street Energy Storage Fund in Texas, Ireland, Great Britain, and Germany.

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.

“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 decarbonising energy system. Our in-house technical team is looking forward to working with LS-ES and its containerised units as construction at Big Rock progresses, and we’re excited to participate in the CAISO market.”

In addition to supplying AiON-ESS containers, LS-ES 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 project.

Construction will soon be underway at Big Rock, and the site is expected to come online in the second half of 2024. The AiON-ESS containers will join several other deployments of the LS-ES energy storage in the United States, and the Big Rock announcement follows the first commercial deployment of the AiON-ESS Energy Series earlier this year.

Visitors to the RE+ clean energy trade show in Las Vegas September 11-14 can walk around one of the actual AiON-ESS containers being used in the Big Rock project. The unit will be on display at the ACE Engineering booth at 17114, with representatives of Gore Street Capital also onsite during the event.

About LS Energy Solutions
LS Energy Solutions, an LS Group company, is a leading provider of grid-connected energy storage solutions. The company brings over a decade of experience innovating energy storage and related technologies, from the first grid-connected lithium-ion storage system to now having over 1.5 GW and 2.5 GWh deployed across 300 projects. The company offers a flexible range of battery and power electronics systems for front-of-the-meter applications, supported by an advanced global manufacturing and testing infrastructure. LS Energy Solutions is a convenient and competitive one-stop supplier for energy storage, from advanced inverters and associated components to fully integrated all-in-one systems. For more information visit

About Gore Street Energy Storage Fund
Gore Street Energy Storage Fund plc (“GSF” or “the Company”) is London’s first internationally diversified listed energy storage fund, launched in May 2018. It holds a portfolio totalling 1.17 GW spread across battery storage facilities in Great Britain and Ireland, Western Mainland Europe and the US. It is listed on the Premium Segment of the London Stock Exchange and included in the FTSE All-Share Index. For more information visit

About Gore Street Capital
Gore Street Capital was formed in 2015 as a global platform to acquire and manage renewable energy solutions. As an experienced renewable energy, infrastructure, and private equity investment manager, it supports robust businesses and high-performing assets that contribute towards the transition to a low-carbon economy.

In 2018, Gore Street Capital created the UK energy storage investment class, listing Gore Street Energy Storage Fund (LSE: GSF) on the premium segment of the London Stock Exchange. As the Investment Manager of GSF, it has played a material impact in the growth of GSF from £30m to finance the acquisition of a 10 MW seed portfolio in Great Britain to a market cap of over £502m.

Gore Street Capital comprises a team of almost 40 energy professionals in GB, Ireland and the US working across finance, construction, engineering, legal and more as it continually brings roles in-house to support the fund. It believes energy storage is crucial in the fight against climate change. For more information visit

Media Contact
Justin Williams
Trevi Communications for LS Energy Solutions
+1 (978) 539-7157‬‬

A photo accompanying this announcement is available at

LS Energy Solutions AiON-ESS Energy Series