Gore Street’s 50MW Drumkee battery asset (above) performed favourably across Q1. Image: Gore Street.

Gore Street Energy Storage Fund has confirmed that energisation for a 79.9MW battery storage asset in Milton Keynes is set to begin on 31 July.

In its latest portfolio and trading update, the fund said the energisation process of the Stony asset has been scheduled with National Grid ESO. Once completed, the site will bring the company’s total operational portfolio to 371.5MW.

Solar Power Portal previously reported that Gore Street acquired the energy storage project from RES in 2021. The project was construction ready, with all land rights, grid connections and planning consents having been secured, and Gore Street was expecting the total capex to be around £30 million spread over 12-15 months.

In its statement, he company warned of decreased revenues for its GB-based assets stating that the market faces increased saturation and declining prices. Portfolios which are solely dedicated to this market are now experiencing a fall in revenues, it added.

Gore Street said the financial year started well for the average revenue from 1-hour systems. Based on data provided by Modo Energy, its GB-based assets generated an average revenue of £7.62 per MW hour for the 6-month period from January to end-June 2023, compared to the UK average of £6.83 per MW/h for 1-hour systems during the same period. Two-hour systems were reported to have generated, on average, just 7.6% more per MW/h than Gore Street's systems average during the period.

Gore Street partner Paula Travesso, speaking on Modo podcast recorded live at Energy Storage Summit 2023 in London in March and discussing the market in 2022, said that two-hour systems still don't make enough revenues to justify the increased capital expenditure required.

The company’s Northern Irish operational assets, which includes Drumkee (50MW) and Mullavilly (50MW), achieved an average revenue of £24.60 per MW/h across the first quarter. This high level of revenue was due to increased system non-synchronous penetration (SNSP) and strong asset-wide availability, the firm said.

“The continued strength of the company’s international portfolio further cements the success of our diversified strategy. While GB has proved fruitful ground since the company’s IPO five years ago, we have anticipated for some time that market saturation will lead to a decline in GB revenue,” said Alex O’Cinneide, CEO of Gore Street Capital Limited, the company’s investment manager.

“The company’s decision to extend its portfolio across Ireland, mainland Europe and the US was driven by this foresight, and the performance of our entire portfolio illustrates the sound judgement of both the company and the investment manager.

“These benefits will support the continued build-out of our construction portfolio, and we’re delighted to have received a firm date for the energisation of the Stony asset. Building scale remains a key element of our strategy, with this site forming the first of over 500MW the company is set to bring online by the end of 2024.”