RWE, the UK’s leading electricity generator, and the largest power producer in Wales, is powering ahead with its largest UK storage project -Pembroke Battery Storage, taking a final investment decision. The circa £200 million development, once constructed, plays an important role in the operation of the Pembroke Net Zero Centre decarbonisation hub in South Wales.
The project construction was announced by the First Minister for Wales, Eluned Morgan - at the Wales Investment Summit, underlining the Welsh Government's commitment to attracting major infrastructure investment that will support the nation's clean energy transition.
The RWE Pembroke Battery project received planning consent in January this year and was also successful in the UK’s latest Capacity Market auction, securing a critical route to market. Construction will start in the first half of 2026, with commissioning and operations expected in the second half 2028, subject to receiving an updated and timely grid connection.
The storage system would be located on a 5.1-hectare area to the south of RWE’s Pembroke Power Station and comprises of 212 lithium-ion battery containers. Once constructed and fully operational, the battery could continually discharge up to 350 megawatts (MW) of electricity directly into the grid for two hours. That’s equal to 700 megawatt-hours (MWh) of stored energy, or equal to keeping the lights on for two hours for almost 300,000 typical UK homes(1).
Nikolaus Valerius, CEO RWE Generation SE: “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.”
First Minister for Wales, Eluned Morgan said: "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.”
Protecting biodiversity
To operate the plant in harmony with the local ecosystem, part of the Pembroke Battery project will involve implementing biodiversity measures in the areas surrounding the operational power station site including meadow planting, native woodland and scrub planting, and developing a new large pond to support local wildlife.
As the UK moves forward towards a clean power system, alongside flexible gas generation, battery and storage projects will have a vital role in maintaining security of supply and supporting the growth of renewables. Battery energy storage technology can also help to enhance grid stability, smoothing out the variability of renewable energy sources by providing a quick response to sudden changes in demand or generation.
RWE is the number one renewable energy generator in Wales and is currently involved in over 3 GW of energy across 12 sites, of which around 1 GW is renewable. The existing renewable energy portfolio already generates around a quarter of Wales’ renewable energy production. The company directly employs around 300 people in Wales in dedicated offices in Baglan and Dolgarrog as well as onsite at power stations. Additionally, wind farms operated by RWE have invested over £21 million into Welsh communities neighbouring our sites, through their community benefit funds.
Battery storage at RWE
As a driver of the energy transition, RWE develops, builds and operates battery storage systems in the USA, Europe and Australia. The company currently operates battery storage systems with a total capacity of around 1.2 Gigawatts (GW), and has a further 2.7 GW under construction. As part of its growth strategy, RWE plans to significantly increase its worldwide battery storage capacity.
