Software provider Arenko will deploy its Nimbus software at Ørsted’s 300MW/600MWh battery energy storage system (BESS).
Arenko’s Nimbus platform will optimise, manage and trade energy from the utility-scale BESS, which is co-located with the 2.9GW Hornsea 3 offshore wind power plant near Norwich.
The project, now referred to as the Iceni BESS but at one time dubbed Boudica, is directly integrated with the offshore transmission infrastructure that connects the wind power plant. The BESS site is scheduled to come online by Q1 2027, slightly behind initial projections that it would be commissioned at the end of this year. It entered construction in March 2025.
The shared grid connection with Hornsea 3, the UK’s largest offshore wind project, makes the Iceni BESS a novel project, regarded as one of the most technically and commercially advanced battery developments in Europe. It is a UK ‘pathfinder’ co-location project, referred to as a “blueprint for the future”.
There are a number of other BESS projects situated close to offshore wind, including Vattenfall’s Battery@Ray and ScottishPower’s Whitelee BESS, but these do not share grid connections with the offshore wind plants from which they store electricity. As the electricity grid cannot handle peak generation from the UK’s wind generation fleet, the National Energy System Operator (NESO) pays generators to power down, costing billions of pounds.
The use of BESS and other flexibility is a way to use offshore wind generation more efficiently, helping smooth variability and reduce curtailment. This applies to all modes of renewable generation, but offshore wind generation is at particular risk of curtailment losses.
CEO of Arenko Rupert Newland noted that the co-location with Hornse 3 “creates significant opportunities” but also comes with challenges, “from forecasting and deciding how and when to allocate capacity in real time, to the technical, data and controls integrations between the two assets”.
According to Katinka Hussman Palbo, vice president of global trading and revenue at Ørsted, the company is “aiming to optimise two very different assets, wind and storage, through a shared connection point, while ensuring that both deliver significant value to the grid”.
Notably, the Danish-headquartered company sold a 50% stake in the wind plant element of the project late last year. The sale, to asset manager Apollo, was kept separate from the BESS element, which is Ørsted’s first large-scale BESS in the UK.