UK ENERGY LAW AND ELECTRICITY SYSTEM: ELECTRICITY MARKET FRAGMENTATION RISK AND CONSOLIDATION POLICY

1. Introduction

Electricity market fragmentation occurs where the electricity sector becomes divided by incompatible rules, market arrangements, network constraints, regional charging structures, technologies or institutional responsibilities. In Great Britain, fragmentation risk must be managed while preserving competition among generators, suppliers, storage providers and emerging flexibility services.

The legal challenge is therefore dual: integration should remove inefficient fragmentation, but consolidation must not create excessive concentration or market power. The Electricity Act 1989, Competition Act 1998, Enterprise Act 2002, Energy Act 2023, electricity licences and industry codes collectively provide the principal framework. Ofgem and the Competition and Markets Authority (CMA) perform complementary regulatory and competition functions.

2. Forms of Electricity Market Fragmentation

Fragmentation may arise at several levels. Geographical fragmentation occurs where network congestion or transmission charging produces materially different economic conditions between locations. Regulatory fragmentation arises where overlapping institutions, licences and industry codes create inconsistent requirements. Technological fragmentation may develop where storage, distributed generation, aggregators and demand-response resources cannot participate equally across markets.

Fragmentation can also occur between wholesale, balancing, capacity and retail markets. Each mechanism may pursue different objectives and settlement arrangements, increasing transaction costs and creating barriers to entry.

Conversely, excessive consolidation can reduce competitive pressure. Policy must therefore seek interoperability and coordination without unnecessarily eliminating independent competitors.

3. Competition and Consolidation Policy

The CMA's major Energy Market Investigation, concluded in 2016, found adverse effects on competition and introduced more than 30 measures directed at improving competition and consumer outcomes.

The investigation considered wholesale market rules, liquidity, foreclosure, transmission losses and retail competition. Ofgem recorded that the CMA identified problems including consumer disengagement, regulatory and technical constraints restricting competition, and weaknesses in the broader regulatory framework.

Thus, consolidation policy does not simply mean creating larger electricity companies. It includes harmonising market rules, improving settlement, facilitating switching, integrating data systems and coordinating network arrangements while maintaining competitive access.

4. Transmission Integration

Transmission arrangements illustrate the tension between integration and fragmentation. Electricity can be traded nationally, but network constraints and transmission losses have important geographical consequences.

The CMA's Electricity Transmission Losses Order requires transmission-loss charging to reflect users' power flows and locations. The Order was subsequently varied in 2024.

This demonstrates that a unified national market may nevertheless incorporate locational economic signals where necessary to represent physical network costs accurately.

5. Case Law: SSE Generation Ltd v CMA

Case Name/Citation: R (SSE Generation Ltd and Others) v Competition and Markets Authority [2022] EWCA Civ 1472.

Facts: The litigation concerned electricity transmission charging and GEMA's response to a charging regime that was incompatible with applicable legal requirements.

Legal Issue: A central question concerned the powers and duties of GEMA when transitioning an electricity charging system from legal non-compliance toward compliance.

Judgment: The Court of Appeal analysed GEMA's regulatory powers, including whether transitional arrangements could contain elements that did not themselves satisfy the governing legal requirements.

Legal Principle/Ratio: Electricity regulators possess significant specialist responsibilities, but market integration and transitional regulation must remain within legally authorised boundaries.

Significance: The case illustrates that consolidation of market arrangements cannot be justified purely by administrative convenience. Integrated charging systems remain constrained by statutory and public-law requirements.

6. Case Study: CMA Energy Market Investigation

Case/Investigation: CMA Energy Market Investigation (2014–2016).

Facts: The CMA conducted a comprehensive investigation into the supply and acquisition of energy in Great Britain and ultimately found adverse effects on competition requiring remedies.

Legal Issue: Whether structural, regulatory and behavioural characteristics of electricity and gas markets impaired effective competition.

Decision: The CMA adopted extensive remedies, including measures concerning consumer engagement, technical market arrangements and electricity transmission losses.

Legal Principle: Under the Enterprise Act 2002 market-investigation regime, structural market problems can justify remedies extending beyond conventional enforcement against individual firms.

Significance: It demonstrates the distinction between beneficial market integration and harmful market concentration. Policy can remove fragmentation while simultaneously protecting competitive diversity.

7. Future Consolidation and Energy-System Integration

The Energy Act 2023 strengthens whole-system coordination through reforms including the Independent System Operator and Planner framework. Future policy increasingly requires coordination between electricity networks, renewable generation, storage, interconnectors, flexibility services and decarbonisation planning.

However, consolidation must be accompanied by open network access, transparent charging, competition supervision, interoperable market rules and regulatory accountability.

8. Conclusion

UK electricity market fragmentation risk reflects the tension between decentralised competition and system-wide coordination. Effective consolidation policy therefore seeks neither complete centralisation nor unlimited fragmentation. Instead, UK law combines Ofgem regulation, CMA competition oversight, transmission rules and industry-code governance to create an integrated electricity system while controlling market power. SSE Generation confirms that even technically complex integration measures remain subject to legal limits, while the CMA Energy Market Investigation demonstrates that market architecture itself may require reform where fragmentation, regulatory constraints or consumer disengagement undermine effective competition.