The seven-year tolling agreement is for the 100MW/330MWh Bramley BESS currently under construction in Hampshire. Image: BW ESS.

BW ESS and its partner Penso Power have signed the first long-term tolling agreement for a single battery energy storage system (BESS) asset in Great Britain with Shell Energy Europe.

The seven-year tolling agreement is for the 100MW/330MWh Bramley BESS currently under construction in Hampshire. In 2021, global energy storage owner-operator BW ESS and Penso Power, which deploys, owns and manages grid-scale battery energy storage projects, announced a joint venture that will see BW ESS fund the build out of Penso’s UK project pipeline totalling over 3GWh.

The fixed price tolling agreement will provide revenue certainty for BW ESS and Penso Power while Shell trades the Bramley BESS into a range of ancillary services and wholesale markets. Shell will pay the owners a fixed fee for the BESS and keep all the upside.

It may be the first tolling deal of this size for a single asset, but the first major UK tolling deal announced in the UK was by Gresham House and Octopus Energy for a 568MW portfolio of operational projects earlier this year.

The 100MW/330MWh Bramley site is the first project in Europe to deploy Sungrow’s PowerTitan 2.0 liquid cooled BESS – a system that combines a 2.5MW Power Conversion System using integrated string inverters and a 5MWh battery into a single container.

This technology means that the 330MWh project takes up a relatively small area. When it is commissioned, which is expected to be in Q4 this year, the Bramley project is expected to be the longest-duration BESS in the UK.

“We are thrilled to partner with the highly experienced energy trading team at Shell on this project,” said Erik Strømsø, CEO of BW ESS. “Bramley showcases our commitment to advancing energy storage solutions that set the bar for the wider market – while pioneering new models for project financing and operation.

“This tolling agreement, which has been some time in the making, demonstrates the attractiveness of longer-duration, higher-performance battery systems. It not only secures long-term revenues for Bramley, but also helps enable the market’s shift away from short-term frequency response towards load shifting.”

According to Rupen Tanna, head of power and systematic trading at Shell Energy Europe, because tolls are a feature of conventional energy trading, Shell has “the trading experience to add significant value, while supporting the UK’s ongoing energy transition”.

Tanna said the experience gained through early tolling deals like this one will be “invaluable” to the wider market.

This echoes what Gresham House’s New Energy assistant fund manager, James Bustin, recently told Energy-Storage.news. Speaking about the tolling deal signed between the fund manager and utility Octopus Energy, Bustin said: “This woke up the wider market to the possibility of this being an option.”