UK ENERGY LAW AND ELECTRICITY SYSTEM: ELECTRICITY MARKET ANTI-FRAGMENTATION INTEGRATION POLICIES

1. Introduction

Electricity-market anti-fragmentation and integration policies are legal and regulatory measures intended to prevent the electricity system from becoming divided into inefficient geographical, institutional, network or commercial segments. In Great Britain, integration is particularly important because generation, transmission, distribution, storage, interconnectors and retail markets must function as components of one coordinated electricity system.

The principal legal foundations include the Electricity Act 1989, Energy Act 2013, Energy Act 2023, competition law, electricity licences and industry codes. The Energy Act 2023 additionally supports more coordinated system planning and governance.

2. National Wholesale-Market Integration

A major anti-fragmentation policy is preservation of a single GB-wide wholesale electricity market. Under the Review of Electricity Market Arrangements (REMA), government examined whether Great Britain should move toward zonal pricing, under which different geographical areas could have different wholesale electricity prices.

In July 2025, the government decided against zonal pricing and retained a single national wholesale market. Its stated concerns included investor uncertainty, complexity, distributional effects between regions and implementation risks. Instead, government adopted Reformed National Pricing (RNP), combining national pricing with stronger locational signals and strategic planning.

The 2026 RNP Delivery Plan confirms that REMA has been replaced by the RNP programme.

3. Network and Spatial Integration

Market integration cannot depend solely upon uniform wholesale prices. Generation must physically reach consumers through sufficient transmission infrastructure.

Consequently, anti-fragmentation policy increasingly integrates market rules with the Strategic Spatial Energy Plan (SSEP), network investment, connection reform and transmission charging. Ofgem's 2026 work on locational charging seeks to encourage new electricity assets to locate consistently with long-term system requirements.

This represents a whole-system approach: generation location, transmission capacity, storage, demand and network development should be coordinated rather than regulated as isolated sectors.

4. Institutional Integration

The Energy Act 2023 provides the statutory architecture for independent system planning and introduces reforms concerning electricity codes and regulatory governance. Integration therefore has an institutional dimension: government, Ofgem, the National Energy System Operator (NESO), network companies and market participants must operate within interconnected planning and regulatory structures.

Licensing and industry codes further prevent fragmentation by imposing common technical, commercial and operational standards across electricity-market participants.

5. Competition and Market Integration

Anti-fragmentation does not mean eliminating competition. Rather, UK policy attempts to combine an integrated network with competitive generation, supply and flexibility markets.

Ofgem's regulatory powers and competition rules can address discriminatory access, market manipulation and conduct capable of obstructing efficient participation. At the same time, common balancing, settlement, connection and network-access arrangements enable electricity businesses to participate within a common market framework.

6. Case Law – Regulatory Integration

Case Name/Citation

R (Scottish Power UK plc) v Gas and Electricity Markets Authority [2022] EWCA Civ 1111

Facts: Energy suppliers challenged aspects of Ofgem's methodology concerning the retail energy price-cap framework.

Legal Issue: The dispute concerned the legality of regulatory methodology and the scope of GEMA's discretion when balancing statutory objectives affecting consumers and regulated market participants.

Judgment: The Court of Appeal examined Ofgem's decision within the statutory regulatory framework and emphasised the importance of assessing regulatory choices according to the legislation governing GEMA.

Legal Principle/Ratio: Specialist regulators possess substantial evaluative discretion where Parliament requires them to balance complex economic and consumer interests, although their decisions remain subject to public-law supervision.

Significance: The case illustrates an important feature of integrated electricity governance: market-wide regulatory rules can coordinate participants, but regulatory integration remains constrained by statutory duties and judicial review.

7. Case Law – Integrated Price-Control Regulation

Case Name/Citation

Northern Powergrid (Northeast) plc and Northern Powergrid (Yorkshire) plc v GEMA, CMA RIIO-ED2 Appeal (2023).

Facts: Distribution network operators challenged elements of Ofgem's RIIO-ED2 electricity-distribution price-control decision.

Legal Issue: Whether GEMA had erred in determining particular expenditure allowances within the common regulatory framework.

Judgment: The CMA upheld one ground concerning the allocation of allowances while rejecting another.

Legal Principle/Ratio: Uniform sector-wide regulatory frameworks do not eliminate scrutiny of their application to individual network operators.

Significance: The decision demonstrates the balance between system-wide regulatory consistency and operator-specific fairness.

8. Conclusion

UK electricity anti-fragmentation policy seeks integration without excessive centralisation. The emerging framework preserves a national wholesale market while using strategic spatial planning, transmission investment, locational charging, common codes, NESO coordination and Ofgem regulation to address regional network constraints. The result is an increasingly integrated model in which competition operates inside a coordinated national electricity architecture designed to support affordability, security of supply, investment and decarbonisation.