RNS Announcements

200 MW acquisition in California

17 February 2023

First acquisition in CAISO grid, and the largest acquisition to date in the US

Gore Street Energy Storage Fund plc (ticker: GSF), London's first listed energy storage fund supporting the transition to low carbon power in the UK and internationally, is pleased to announce that it has agreed to acquire Big Rock, a 200 MW / 400 MWh energy storage project (the "Project") located in Imperial County, California, United States from Avantus (the "Seller" - formerly 8minute). 

Following this acquisition, GSF's internationally diverse portfolio will consist of 27 projects with a total capacity of 1,173.2 MW of operational and construction assets across the UK, Ireland, Germany and the Electric Reliability Council of Texas (ERCOT) and California Independent System Operator (CAISO) grids within the US, offering investors exposure to five different grid partners. Big Rock will be the Company's first investment in California and further diversifies the Company's revenue streams and geographic exposure. The Project will be connected to CAISO, one of nine independent system operators (ISO) in North America. The CAISO grid provides electricity to 80% of California and a small part of Nevada.

CAISO offers a particularly attractive opportunity for energy storage investment due to California's significant deployment of solar capacity and ongoing retirement of baseload thermal generation across the state, creating significant opportunities for services that aim to deliver stability to the grid. The asset will support CAISO's grid by providing ancillary services while also participating in the capacity market (Resource Adequacy) and wholesale trading.

The construction-ready Project has secured material land rights, planning consents and a grid connection scheduled for H2 2024. Commercial operations will commence shortly thereafter as a battery supply contract for all battery cells for the two-hour duration site, and engineering procurement and integration contracts have been secured.

The Project will be eligible to benefit from an investment tax credit for up to 30% of qualifying capital expenditure via the Inflation Reduction Act, which was passed in late 2022.

The Project acquisition costs, including capex spent on or around the closing date, is approximately $110 million, including development fees and milestone payments to date for an EPC contract of all battery cells. Following the transaction, the Company's cash position is c.£144 million, of which c.£66 million is already committed through contractual obligations to construct announced portfolio projects. The remaining funds are allocated to the Company's pre-construction / construction projects but are not yet contractually committed.

Gore Street's investment manager, Gore Street Capital Limited (the "Investment Manager"), estimates the Project will have an unlevered IRR in the range of 10-12%, in line with GSF's target.


Patrick Cox, Chair of the GSF Board, commented:

"We are delighted to announce this landmark international acquisition for the Company. This is the Company's first acquisition in the Californian market and follows our successful entry into the energy storage markets of Texas and Germany in 2022.

With this acquisition, the Company is now diversified across five high-growth grids, underpinning our push into international markets, where we continue to see attractive new investment opportunities in line with our target returns. We remain dedicated to performing competitively across the sector's core metrics - cost per MW and revenue per MW / MWh - as this ultimately drives returns for shareholders.

We look forward to updating the market over the next 18 months as 361.7 MW of projects are set to become operational across Great Britain, Ireland and Texas."


Alex O'Cinneide, CEO of the Investment Manager, is a non-executive director of the Seller and holds employee ownership plan units in the Seller. In order to manage any actual or perceived conflict of interest arising in relation to the acquisition of the Project, Mr O'Cinneide has not participated in any discussions concerning the approval of the acquisition and the Company's board of directors has approved the transaction.


For further information:

Gore Street Capital Limited


Alex O'Cinneide / Paula Travesso

Tel: +44 (0) 20 3826 0290


Shore Capital (Joint Corporate Broker)

Anita Ghanekar / Rose Ramsden / Iain Sexton (Corporate Advisory)

 Fiona Conroy (Corporate Broking)

Tel: +44 (0) 20 7 408 4090


J. P. Morgan Cazenove (Joint Corporate Broker)

William Simmonds / Jérémie Birnbaum (Corporate Finance)

Tel: +44 (0) 20 7742 4000


Buchanan (Media enquiries)

Charles Ryland / Henry Wilson / George Beale

Tel: +44 (0) 20 7466 5000

Email: [email protected]


Notes to Editors

About Gore Street Energy Storage Fund plc

Gore Street is London's first listed energy storage fund and seeks to provide Shareholders with an opportunity to invest in a diversified portfolio of utility-scale energy storage projects. In addition to growth through exploiting its considerable pipeline, the Company aims to deliver consistent and robust dividend yield as income distributions to its Shareholders.