RWE has decided to back what it says will be its largest battery energy storage facility in the UK, a 350MW, two-hour system at Pembroke in South Wales designed to support both the local grid and the company’s wider decarbonisation plans.
The circa £200 million Pembroke Battery Storage project has planning consent in place and a contract secured in the UK Capacity Market, with construction due to begin in the first half of 2026 and commissioning targeted for the second half of 2028, subject to an updated grid connection.
The project was formally announced by the First Minister for Wales, Eluned Morgan, at the Wales Investment Summit, signalling the Welsh Government’s desire to attract large-scale energy infrastructure that can underpin its net zero ambitions.
RWE plans to build the battery on a 5.1-hectare site to the south of its existing Pembroke Power Station. The scheme will comprise 212 lithium-ion battery containers and, once operational, will be capable of discharging up to 350MW of electricity into the grid for up to two hours – equivalent to around 700MWh of stored energy, or keeping the lights on for close to 300,000 typical UK homes for two hours.
The company says the battery scheme will be accompanied by a package of biodiversity measures around the operational power station site, including meadow creation, native woodland and scrub planting, as well as a new large pond intended to support local wildlife.
Pembroke Battery Storage is also expected to play a central role within the wider Pembroke Net Zero Centre, RWE’s planned decarbonisation hub for South Wales.
Nikolaus Valerius, CEO RWE Generation SE, said, “In a dynamic energy world with more and more renewable energy, there is an increasing need for mature technologies that can instantly support the electricity grid. Battery storage systems are ideal for this because they are fast, efficient and competitive. Our Pembroke Battery is our UK flagship storage project and will make an important contribution to stabilising the UK energy market by efficiently storing surplus energy and feeding it into the national grid in a targeted manner when required.”
Welsh Government sets out clean energy role
The Welsh Government has been keen to position projects such as Pembroke as part of a broader regional industrial strategy, linking clean power, jobs and local supply chains.
Eluned Morgan, First Minister for Wales, noted, “This significant investment by RWE demonstrates Wales’ central role in the UK’s transition to clean and renewable electricity. The Pembroke Battery Storage facility will support our ambitions for a cleaner, more secure energy future while at the same time creating opportunities for good jobs and local communities across South Wales.”
“Innovative projects like this showcase how Wales is leading the way in the development of renewable energy technology. This is helping to build a greener economy for generations to come.”
Tom Glover, RWE UK Country Chair, added, ”Wales has significant potential to lead the UK’s clean energy transition across wind, solar, storage, hydro, and emerging technologies. Despite the challenges facing energy projects everywhere, we see a government determined to unlock this opportunity for the benefit of communities across Wales – something we strongly support.”
It should also be noted that Wales will be home to the UK’s first small modular reactor (SMR), with the Government in Westminster hoping that the site in Anglesey, North Wales will kickstart a nuclear revolution for the whole of the United Kingdom.
