How Sungrow & Fidra Will Transform the UK's Battery Capacity

Sungrow has been selected as technology provider for the Thorpe Marsh Battery Energy Storage System (BESS), which will become the UK's largest battery project when it comes online in towards the middle of 2027.

The facility is located in South Yorkshire and will add capacity equivalent to more than 20% of the UK's current battery storage fleet in a single installation, capable of storing 1.4GW/3.1GWh at full capacity.

Fidra Energy is the firm behind the project. The Edinburgh-based company secured around US$970m in financing from EIG and the UK National Wealth Fund for the project, as well as a syndicate of international lenders including NatWest, Santander CIB, Deutsche Bank, Société Générale and Standard Chartered Bank.

Climate tech at scale

Sungrow will supply its PowerTitan 2.0 battery energy storage system with 1.6GW/3.3GWh of capacity.

The fully liquid-cooled, modular system is designed for utility-scale applications and will be capable of exporting over 2,000 GWh annually.

When fully operational, Thorpe Marsh will have enough capacity to power 785,000 homes each year.

"This is a landmark moment for the UK's energy transition and for the global energy storage industry," says James Li, Director ESS Europe at Sungrow.

"Thorpe Marsh demonstrates how cutting-edge battery technology can accelerate the shift to a cleaner, more resilient power system."

Revenue structure provides financial stability

Offtake agreements are always key to the development of renewable energy or climate tech projects as they allow producers to guarantee custom a long way into the future. This is just the case with Thorpe Marsh.

The project has secured long-term offtake agreements with EDF, Octopus Energy and Statkraft, with these three firms covering roughly 80% of the facility's capacity.

Thorpe Marsh has also been awarded a 15-year capacity market contract from the UK Government which is set to start in 2028.

These arrangements provide revenue certainty for what represents one of the largest standalone battery storage facilities to secure project financing globally.

Chris Elder, CEO of Fidra Energy, says that Sungrow has "demonstrated that it will be an excellent partner" and that the company looks forward to "working with them to support our UK and European growth ambitions".

UK battery storage momentum

The UK added almost 2GW/3.5GWh of grid-scale battery storage in the first ten months of 2025, representing a 36% year-on-year increase.

Total operational capacity now stands at 7.86GW/11.8GWh across the country.

The rapid expansion reflects the growing need for flexibility assets as the UK works toward its 2035 net zero power grid target.

Large-scale battery installations like Thorpe Marsh are essential for integrating variable renewable generation and maintaining grid stability as fossil fuel generation is phased out.

Sungrow's growing portfolio of climate technologies

Alongside Thorpe Marsh, Sungrow will supply technology for Fidra Energy's 500MW/1.1GWh West Burton C energy storage project.

West Burton C is also backed by EIG and the National Wealth Fund.

Construction at Thorpe Marsh has commenced, with commissioning scheduled to begin in mid-2027.

The project represents a significant test of whether utility-scale battery storage can be deployed at gigawatt scale while maintaining operational efficiency and grid integration standards.