GSR036: System Access Reform: Review of the voltage limits
What is being proposed
This modification is to review the voltage limits applicable to operational timescales and the potential for provision of some flexibility around them.
Current status
08/12/25 - Proposal raised on 06 November 2025 and was presented at the SQSS Panel on 05 December 2025. A revised Proposal to be circulated with suggested improvements for Panel approval. 02/02/26 - Proposal undergoing amendments based on industry feedback and to be circulated with Panel for approval 03/03/2026 - Proposal to be presented at the SQSS Panel on 24 March 2026.
Details
Timeline
Analysis
NESO proposes reviewing voltage limits that apply during operational timescales and introducing flexibility around these constraints. The modification affects transmission owners, NESO, distribution networks, generators, and directly connected customers. Cross-code changes to Grid Code and STC may be required.
Why it matters
This creates a tension between operational reliability and economic efficiency — relaxing voltage constraints could reduce curtailment costs but requires careful calibration to avoid system instability. The proposal suggests moving from binary constraints toward more flexible operational boundaries, which could favour generators currently constrained off.
Key facts
- •Proposal raised 06 November 2025
- •Panel presentation scheduled 24 March 2026
- •Medium impact on all network parties and generators
- •Standard governance route to CAC