SYSTEM OPERATOR (TSO)

National Energy System Operator

System operator (TSO)Great Britain

The independent system operator for Great Britain.

Developments

21 tracked developments touching this entity.

06 NOV 2026

NESO raises STC modification PM0124 to revise Expansion Constant & Expansion Factor data requirements following CMP315/CMP375

Regulatory review · ENERGY MARKETS · GB

04 NOV 2026

P502 Timetable Firms Up: Elexon Specifies January 2027 Assessment Procedure Consultation Window

Regulatory review · BALANCING MARKETS · Great Britain

29 OCT 2026

Zenobe Energy submits BSC Modification P522 to introduce subsidy-adjusted Shadow Bid Price for Balancing Mechanism transparency

Regulatory review · BALANCING MARKETS · Great Britain

28 OCT 2026

BSC Modification P493 advances through Workgroup assessment to improve Transmission Loss Factor transparency and forecasting

Regulatory review · BALANCING MARKETS · Great Britain

23 OCT 2026

Elexon confirms P518 approved as Self-Governance Modification, implementation set for 5 November 2026

Implementation · BALANCING MARKETS · Great Britain

23 OCT 2026

NESO Advances Demand for Constraints (DfC) Long-Term Constraint Management Service Toward 2027 Procurement

Implementation · FLEXIBILITY MARKETS · GB (Scotland - B2, B4, B5, B6 boundaries)

22 OCT 2026

NESO Redirects South West Reactive Power Needs to New Mid-term Reactive Power Market

Go-live · BALANCING MARKETS · GB

20 OCT 2026

NESO's Constraints Collaboration Project advances GB constraint-management reforms: DFS constraint capability live, Storage Behind Constraints consultation roadmap set, gas pre-gate CMM rejected, CMIS intertrip extensions tendering

Implementation · FLEXIBILITY MARKETS · GB

16 OCT 2026

NESO proposes CMP457 to overhaul ORPS reactive power compensation methodology under CUSC

Proposal · BALANCING MARKETS · GB

15 OCT 2026

P502 Assessment Procedure Consultation Slips Four Months to January 2027 (TBC), Delaying GB Supplier-Aggregator Compensation Timeline

Regulatory review · BALANCING MARKETS · Great Britain

13 OCT 2026

Ofgem extends NESO's C1.17 derogation on NTC restrictions to 2030, mandates fresh reviews of NTC Calculation Policy and Commercial Compensation Methodology by 2027

Decision · ENERGY MARKETS · GB

01 OCT 2026

BSC Modification P522 Proposes Subsidy-Adjusted Shadow Bid Price for GB Balancing Mechanism Transparency

Proposal · BALANCING MARKETS · Great Britain

30 SEPT 2026

NESO's Q3 2026 Update Advances Demand-Side Flexibility Routes-to-Market Barrier Removal Programme

Implementation · FLEXIBILITY MARKETS · Great Britain

15 SEPT 2026

Elexon FMAR consultation notice reconfirmed with no new design or milestone details

Consultation · FLEXIBILITY MARKETS · United Kingdom

11 SEPT 2026

NESO IEP5 presents finalized CBA methodology and cost estimates for Lowering BM Threshold and Shorter Settlement Period reforms

Consultation · BALANCING MARKETS · United Kingdom

11 SEPT 2026

NESO's IEP4 pre-read details CBA sensitivity/variant methodology and granular cost framework for GB balancing and settlement reforms

Proposal · BALANCING MARKETS · United Kingdom

10 SEPT 2026

NESO CMP405 Proposes Splitting TNUoS Year Round and Peak Security Locational Demand Signals to Reward Storage Import Location

Proposal · FLEXIBILITY MARKETS · United Kingdom

10 SEPT 2026

NESO's BSC Modification P502 moves through Assessment Procedure to create Supplier/Aggregator compensation mechanism for ABSVD-driven imbalance adjustments

Regulatory review · BALANCING MARKETS · Great Britain

09 SEPT 2026

Elexon confirms BSC Modification P511 fully implemented 24 August 2026, correcting Ofgem approval date to 10 August 2026

Go-live · BALANCING MARKETS · Great Britain (BSC / Elexon)

09 SEPT 2026

Elexon confirms P518 Report Phase Consultation on ABSVD data provision for CLASS has closed

Regulatory review · BALANCING MARKETS · Great Britain (BSC / Elexon)

04 SEPT 2026

Ofgem publishes BP3 performance assessment of NESO, flags connections reform and value-for-money gaps

Regulatory review · ENERGY MARKETS · Great Britain