Ørsted completes construction of 600 MWh UK battery storage project at offshore windfarm

Global offshore wind developer Ørsted has completed construction of its 300 MW / 600 MWh Iceni battery energy storage system (BESS) near Norwich, in Norfolk, England. It is its first large-scale BESS project in the UK. A construction start cememony was held on March 5, 2025, making large-scale completion in around a year and a half.

The battery storage facility is located alongside the onshore converter station for Ørsted’s Hornsea 3 Offshore Wind Farm. A total of 170 Tesla Megapacks have been installed at the site, and Ørsted stated that once operational, it will be one of the largest BESS projects in Europe. 

While the exact Megapack variant wasn’t specified, site photos supplied by Ørsted show Tesla Megapack 2XL in use.

“It’s a milestone moment for Ørsted that construction is now complete on our first large-scale battery energy storage system in the UK,” said Beatrice d’Eufemia, project manager for Iceni BESS at Ørsted.

Following the construction milestone, Ørsted said the project is now entering the final stages of mechanical and electrical installation works, with installation and termination of cross-site cables ongoing. In addition, the first stage of commissioning and testing activities are underway, while preparations are being made to energize the project’s transformer. 

The developer highlighted the project’s technical complexity, outlining that it uses a split layout of the Norfolk site, encompassing two areas that are separated by the Hornsea 3 Onshore Converter station. The sections are connected by 18 x 33 kV cables, each more than 600 meters in length. 

Danish company Ørsted said additional engineering challenges have arisen from the shared grid connection point with the Hornsea 3 Offshore Wind Farm compared to a standalone grid connection. 

In addition to Ørsted and Tesla, Hitachi Energy and Knights Brown are among the companies involved in the Iceni BESS.

Earlier this year in the U.S., Ørsted reached commercial operations on the 250 MW / 500 MWh Old 300 Storage project in Needville, Texas. It is co-located with a 430 MW solar project.