Committee publication · Correspondence · 25 March 2026 · HC 459
Correspondence from Neso following up from 4 March session, dated 16 March 2026
Summary
NESO (National Energy System Operator) writes to the Scottish Affairs Committee following 4 March 2026 oral evidence on GB Energy and the net zero transition. NESO clarifies its statutory limitations on prioritising community energy projects, explains transmission infrastructure challenges specific to Scotland, and provides data showing Scotland accounted for 93–96% of GB curtailment in 2023–25 due to network constraints, requiring substantial investment to meet the 2030 clean power target.
Key findings
- NESO cannot give priority treatment to community energy projects under reformed connections methodologies (approved April 2025); any such policy change requires UK government decision-making and a robust definition of community energy.
- Scotland's higher transmission impact thresholds reflect lower network capacity and different voltages compared to England; new onshore circuits in Northeast Scotland, voltage upgrades in Highland, and substation investments in Central Scotland are underway to improve power flows.
- Scotland accounted for 93.87% (2023), 96.03% (2024), and 96.29% (2025) of total GB curtailment for balancing mechanism assets, with ~70% of balancing costs linked to constraints.
- Balancing Services Use of System (BSUoS) charges contributed ~3.4% of domestic electricity bills (£3/month) in 2024/25; new network infrastructure is essential to prevent rising system costs.
- NESO will publish refreshed transmission reinforcement recommendations (Beyond 2030) in summer 2026 and a new 25-year Centralised Strategic Network Plan in 2028, integrating electricity, gas, and hydrogen transmission.
Tone
FactualTopics
Key actors
Patricia Ferguson MP, Julian Leslie, National Energy System Operator (NESO), Ofgem, UK Government, Scottish Government, Welsh Government, SSE
Notable line
“NESO is not permitted to give priority treatment to projects seeking to connect based on their ownership model.”
Key Quotes
“NESO is not permitted to give priority treatment to projects seeking to connect based on their ownership model.”
“… it is not for NESO to make the policy changes that the community energy sector is seeking”
“… the reasons for different transmission impact thresholds in different parts of GB are a relatively straightforward reflection of the differences in the networks that we have, and the different voltages that the transmission system operates at in Scotland compared with in other parts of GB”
“At present around 70% of balancing costs are linked to constraints, with thermal constraint (the physical limit of a cable to carry more power) contributing most.”
“… building new or upgrading of existing network is necessary to prevent ever increasing system costs being passed to the consumer, whilst also representing a significant opportunity for investment in our national critical infrastructure”
Source · parliament.uk record ↗