SETTLEMENT REFORM IN ELECTRICITY MARKETS

1. Meaning and Purpose

Settlement reform concerns changes to the legal, technical, and financial arrangements through which electricity-market participants are charged or credited for differences between the electricity they contracted to buy or sell and the electricity actually generated or consumed. In Great Britain, these arrangements are principally governed through the Balancing and Settlement Code (BSC), administered by Elexon.

Settlement is fundamental because electricity must continuously remain balanced. Suppliers purchase electricity for customers, generators contract to deliver electricity, and actual metered positions are compared with contracted positions. Differences create imbalance charges. Reform seeks to make settlement more accurate, faster, transparent, and capable of accommodating smart meters, renewable generation, storage, demand response, and flexible consumption.

2. Market-Wide Half-Hourly Settlement

The most significant contemporary reform is Market-wide Half-Hourly Settlement (MHHS). Traditional settlement frequently relied upon consumption profiles and estimates rather than actual half-hourly measurements. Smart-meter infrastructure permits consumers' real electricity use during individual settlement periods to be measured.

Earlier reform occurred through BSC Modification P272, approved by Ofgem in 2014, which required certain larger non-domestic consumers in Profile Classes 5–8 to be settled using actual half-hourly consumption information.

MHHS extends this principle across the retail market. It is designed to strengthen incentives for suppliers to encourage customers to shift electricity demand away from expensive or constrained periods. It therefore connects settlement law with demand flexibility, renewable integration, network efficiency, and decarbonisation.

In September 2025, BSC Modification P478 implemented the principal BSC provisions required for the MHHS target operating model. Elexon states that full migration is intended to finish in May 2027, followed by a shortened settlement timetable.

3. Governance of Settlement Reform

Settlement reform is not merely technical. BSC modifications must operate through legally structured governance arrangements involving consultation, industry assessment, the BSC Panel, Elexon, and ultimately regulatory oversight by the Gas and Electricity Markets Authority.

For example, P423 introduced governance arrangements requiring Elexon to manage MHHS transparently, consultatively, and impartially while imposing implementation, testing, qualification, and migration obligations on participating organisations.

Settlement reform must additionally comply with data-protection requirements because half-hourly settlement depends upon granular consumer consumption data. Ofgem has therefore accompanied MHHS policy with specific decisions and data-protection impact assessments governing access to half-hourly meter information.

4. Case Law

Case Name/Citation

R (SSE Generation Ltd) v Competition and Markets Authority [2022] EWCA Civ 1472

Facts: The dispute concerned GEMA's approval of changes to electricity transmission charging methodology and the regulatory code governing electricity-network charges.

Legal Issue: Whether GEMA could lawfully approve an interim methodology while moving the charging framework toward full legal compliance.

Judgment: The Court of Appeal recognised that GEMA possessed a significant regulatory margin of judgment when determining how to transition the electricity charging regime into compliance with applicable law.

Legal Principle/Ratio: Industry codes cannot override the regulator's statutory duties. Where conflict exists, statutory obligations prevail over contractual code arrangements.

Significance: Settlement and balancing reforms must therefore comply with superior statutory requirements even where technically complex transitional arrangements are necessary.

Case Name/Citation

R (British Gas Trading Ltd) v Gas and Electricity Markets Authority [2019] EWHC 3048 (Admin)

Facts: British Gas challenged aspects of Ofgem's methodology under the energy price-cap regime, particularly the treatment of wholesale-cost allowances.

Legal Issue: Whether GEMA had properly considered relevant evidence and statutory factors when designing the regulatory methodology.

Judgment: The High Court upheld British Gas's challenge on the relevant issue and required GEMA to reconsider its calculation.

Legal Principle/Ratio: Technical electricity-market regulation remains subject to ordinary administrative-law requirements, including rational consideration of relevant evidence and statutory duties.

Significance: The principle directly applies to settlement reform: complex algorithms, settlement parameters, and market-code methodologies cannot escape judicial scrutiny merely because they are technically specialised.

5. Conclusion

Settlement reform transforms electricity-market governance by replacing estimated consumption with granular metered data, improving imbalance allocation, accelerating settlement, and supporting flexible demand. In Great Britain, MHHS, P272, P423 and P478 demonstrate the movement toward data-driven settlement. However, reform remains legally constrained by the Electricity Act framework, BSC governance, data protection, consultation duties, and administrative law. Courts confirm that regulatory expertise permits considerable discretion, but settlement rules must remain lawful, evidence-based, transparent, and consistent with statutory objectives.