The Pen Y Cymoedd Wind Farm – Battery Energy Storage System is a 22,000kW energy storage project located in Aberdare, Wales, UK.

The electro-chemical battery energy storage project uses lithium-ion as its storage technology. The project was announced in 2017 and was commissioned in 2018.


The Pen Y Cymoedd Wind Farm – Battery Energy Storage System was developed by Vattenfall.

The key applications of the project are frequency regulation, renewables capacity firming and renewables energy time shift.

Contractors involved

Bayerische Motoren Werke and Vattenfall have delivered the battery energy storage project.

Additional information

The 22 MW facility will be constructed at the 230 MW Pen Y Cymoedd wind farm in South Wales. Vattenfall won a 22 MW, four-year enhanced frequency response (EFR) contract from National Grid.
The project equipped with up to 1,000 lithium-ion batteries each with a capacity of 33kWh supplied by BMW.

About Vattenfall

Vattenfall AB (Vattenfall) is a state-owned energy company that generates, distributes and sells electricity and heat. The company also conducts the sale of gas and energy trading. Vattenfall generates power through various sources of energy including wind, nuclear, hydro, natural gas, solar, coal, biomass and waste. It produces and distributes district heating and supplies to households and industries in metropolitan areas. In addition, the company provides energy services such as battery storage, network services, charging solutions for electric vehicles, heat pumps, solar panels and smart meters. It serves households, businesses, electricity and gas customers. It has presence in Denmark, Finland, Germany, the Netherlands and the UK among others. Vattenfall is headquartered in Solna, Stockholm, Sweden.


All publicly-announced energy storage projects included in this analysis are drawn from GlobalData’s Power IC. The information regarding the projects are sourced through secondary information sources such as country specific power players, company news and reports, statistical organisations, regulatory body, government planning reports and their publications and is further validated through primary from various stakeholders such as power utility companies, consultants, energy associations of respective countries, government bodies and professionals from leading players in the power sector.