Key facts
- Britain's largest community solar farm, Derril Water, has been forced to shut down for the summer.
- The shutdown is a measure to prevent the local grid from being overloaded by renewable energy.
- The cooperative scheme's nearly 10,000 members are expected to lose about £2 million in revenue.
- The National Energy System Operator (Neso) ordered the shutdown due to concerns about grid stability from high rooftop solar generation.
- Necessary grid upgrades are anticipated to be completed by September.
Britain's largest community solar farm, the Derril Water solar park in North Devon, has been forced to shut down for its entire first summer due to concerns over grid overload. The National Energy System Operator (Neso) ordered the shutdown, along with that of a vital super grid transformer, to prevent the large amount of rooftop solar in the area from destabilizing the power grid by triggering a thermal overload. This unexpected closure is projected to cost the cooperative scheme's nearly 10,000 members approximately £2 million in lost revenue. The cooperative's board expressed frustration over the lack of warning and the timing of the shutdown, which significantly impacts their finances and ability to pay members. The issue stems from the difficulty in managing voltage fluctuations during summer when solar generation is high, and necessary grid upgrades have been delayed, with new equipment now expected by September. The project, funded by £20 million from members and a £22 million loan, was originally part of a scheme by Ripple Energy, which went out of business in early 2025. Despite construction delays and rising costs, Derril Water began generating electricity last September under a volunteer board. National Grid confirmed it curtailed generation to maintain system security, and is working with Neso on solutions.