Metlen Energy (the Greek energy group formerly known as Mytilineos) has signed a Balance-of-Plant contract with developer Pulse Clean Energy covering grid connection and construction work on the Penn battery storage project near Wolverhampton, in England’s West Midlands. The project is rated at 129 MW and 362 MWh — up from an original design of 310 MWh, after the system was reconfigured from two hours of storage duration to 2.4 hours — and Metlen is targeting energisation by the end of 2027. Metlen describes Penn as the largest energy storage development it has undertaken in the UK by storage capacity to date.
The battery hardware itself comes from Chinese manufacturer Envision Energy, which was selected by Pulse Clean Energy to supply the system on its Gen 7 BESS platform, a grid-forming battery technology; that supply deal was announced separately at the Intersolar Europe trade show in Munich in July 2026, at the project’s original 310 MWh sizing. Norwegian energy company Statkraft has separately signed an agreement to handle Penn’s route-to-market and trading optimisation, structured with what Statkraft describes as a long-term income guarantee to support the project’s financing. Statkraft’s own announcement lists the project at a slightly different 128 MW and targets operations in “early 2028,” a modest variance from Metlen’s 129 MW/end-2027 figures that likely reflects differences in reporting timing or milestone definitions rather than a substantive change in project scope.
Pulse Clean Energy, the UK developer behind the project, frames it as supporting grid resilience and industrial decarbonization in the West Midlands, a region with a manufacturing and logistics base. Pulse CEO Trevor Wills said Statkraft’s “strong track record in optimisation and market access gives us confidence that the asset will achieve strong and stable returns,” while Statkraft’s UK and Ireland head of storage markets, Nick Heyward, said the deal expands the company’s flexible-assets portfolio in Great Britain to 4.3 GW. Pulse has said it expects Penn to avoid roughly 30,000 tonnes of CO2 emissions a year, equivalent to taking about 6,500 petrol vehicles off the road.
This isn’t the first time Metlen and Pulse Clean Energy have worked together: Metlen previously delivered a smaller, 73.31 MWh battery project called Coal Pit for Pulse, making Penn a repeat engagement between the two companies rather than a first-time pairing. More broadly, Penn sits within a UK battery storage business Metlen has been building through its M RESET platform, which the company says now spans around 30 battery storage units in the UK — including standalone and hybrid solar-battery projects — with nearly 2 GWh of combined capacity across its various partnerships.
Penn also fits into a wider European buildout for Metlen beyond the UK. In Italy, the company has developed a 25 MW/75 MWh battery project in Apulia’s Brindisi province, financed with €18 million in long-term debt and backed by a seven-year tolling agreement with Dolomiti Energia Group. In its home market of Greece, Metlen has built a 330 MW/790 MWh standalone battery system in Thessaly — which it describes as the largest in Greece and among the largest in Europe, connected directly to the national transmission grid — as well as a smaller 48 MW/96 MWh project in Polygyros, Halkidiki, financed partly through Greece’s EU-backed “Greece 2.0” recovery plan. Taken together, the UK, Italian, and Greek projects position Metlen as a battery storage developer with a genuinely pan-European footprint, rather than one concentrated in its Greek home market.
