Question to the Department for Energy Security & Net Zero:

To ask the Secretary of State for Energy Security and Net Zero, what (a) his Department’s and (b) NESO’s estimate of the magnitude in MWh and the aggregate cost of any constraints of embedded solar generation resulting from instructions at the distribution level by Distribution Network Operators in their emerging role as Distribution System Operators for all years in which such constraints and costs have occurred since 2020.

The National Energy System Operator (NESO) is responsible for operating Great Britain’s electricity system, which includes managing constraints. NESO publishes total balancing costs, which can be found here: Constraint Breakdown 2025-2026 | National Energy System Operator. Actions taken in the Balancing Mechanism, including bids taken by individual Balancing Mechanism Units, can be accessed here API documentation | Insights Solution.

Government is working to reduce constraints and improve energy security and resilience by accelerating the building of new electricity network infrastructure to increase capacity on the system.