Derril Water Solar Farm Shut All Summer Over Grid Fears
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- Derril Water solar park — Britain's biggest community solar project, serving nearly 10,000 member-owners — was ordered shut for the summer by the National Energy System Operator (Neso) over fears that dense rooftop solar in north Devon would trigger a thermal overload on the transmission network.
- Neso instructed National Grid to switch off a vital "super grid transformer" for the season, because surging local solar generation was pushing the network's voltage beyond safety limits during long summer days.
- The cooperative's board told members the shutdown will cost roughly £2m in lost revenue before the park is allowed to restart in September, and that the project will receive no compensation or insurance to cover the shortfall.
- Network operators were aware of the looming problem since 2023, according to the board, but specialist equipment upgrades originally scheduled for completion by the end of 2025 were delayed and are now not due until September 2025.
- The £42m project was funded through £20m raised from members and a £22m long-term bank loan, with members having signed on via Ripple Energy — which collapsed into administration in early 2025 before the park ever generated power; 1st Energy later bought Ripple out and the park began operating in September 2024 under a volunteer board.
- A National Grid spokesperson confirmed it had curtailed local generation to keep the system secure after Neso's transformer shutdown order, and said it is "working with Neso to help provide solutions"; Neso declined to comment.
Why it matters: Nearly 10,000 small investors who bought into Britain's flagship shared solar park lose an estimated £2m of expected summer income — money they were promised as £200+ annual savings on energy bills — because grid upgrades known about since 2023 weren't delivered on time, exposing how Britain's aging transmission network is now throttling the very community energy projects it was built to host.
