Voltwise Buys SMS Battery Unit, Adds 460 MW in UK

• Voltwise Power acquires SMS’s 460 MW UK battery portfolio, expanding its storage fleet to 9 % of the national total and eyeing a 2 GW development pipeline.

London-based Voltwise Power has taken over the battery energy storage division of Smart Metering Systems (SMS), picking up 460 MW of assets in operation or under construction across Britain. The deal, struck just 15 months after KKR bought SMS for £1.3 billion, turns Voltwise—backed by private-equity house Sandbrook Capital—into one of the country’s biggest standalone storage owners.

What’s in the basket?

• 320 MW / 350 MWh live: seven grid-connected batteries, including Barnsley (40 MW), Berkeley (50 MW) and Brook Farm (50 MW).

• 140 MW / 280 MWh building: four sites scheduled online by mid-2026.

• Early-stage pipeline: additional projects push Voltwise’s total development slate toward 2 GW. 

Chief executive Russell Alton called the purchase “an exciting moment in Voltwise’s evolution,” adding that the company now has the scale to layer in hybrid renewables and sophisticated optimisation software.

Why it matters

Great Britain’s battery fleet tipped past 5 GW this spring and is on track to connect a further 17 GWh by 2026. Voltwise’s new holdings give it roughly 9 % of the nation’s live-plus-in-build capacity, extending its footprint from Suffolk to the Scottish Central Belt.

Money talk

Although terms stayed private, City bankers peg ready-to-operate UK BESS assets at £0.8-1 million per MW, implying north of £350 million for the running slice alone, with upside once the under-construction projects energise. Revenues from ancillary services and looming grid-balancing reforms are keeping valuations buoyant.

Next moves

• Voltwise will slot the SMS fleet into its AI-driven dispatch platform and consider adding co-located solar for hedging.

• Germany is next: the company already controls its first consented 200-MWh project there.

• SMS will recycle proceeds into smart-meter roll-outs and energy-services contracts, sticking to its core infrastructure mission.