1. Introduction

Offshore electricity hubs are emerging as a major component of future electricity infrastructure. An offshore electricity hub is a coordinated offshore facility or network that connects multiple electricity-generating projects—particularly offshore wind farms—with several transmission systems, countries, markets, or neighbouring energy infrastructure. Unlike a conventional offshore wind project that generally sends electricity to one coastal state, a hub can operate as a multi-purpose transmission and energy-interconnection platform.

The legal governance of offshore electricity hubs is therefore considerably more complex than ordinary electricity regulation. It involves the interaction of energy law, maritime law, environmental law, transmission regulation, international law, competition law, investment law, planning law, and cross-border electricity-market rules.

The central legal questions include:

Who owns and operates an offshore hub?

Which state has jurisdiction over the installation?

How are transmission capacity and interconnector revenues allocated?

Which regulator supervises the hub?

How are offshore wind developers connected to the hub?

How are environmental and maritime conflicts addressed?

What happens when electricity crosses several national borders?

Who bears responsibility for outages, congestion and system failures?

How are security and critical-infrastructure risks regulated?

Because offshore hubs frequently involve several jurisdictions, effective governance requires coordinated rather than purely national regulation.

2. Meaning and Characteristics of Offshore Electricity Hubs

An offshore electricity hub may perform several functions simultaneously:

Electricity collection from offshore wind farms;

Transmission to one or more coastal countries;

Interconnection between national electricity systems;

Electricity-market integration;

Potentially hydrogen production or other energy conversion;

Provision of balancing, storage or flexibility services.

The legal distinction between a generation asset and a transmission asset becomes important. A hub may be physically located offshore but legally connected to several national electricity systems.

The proposed North Sea energy-island and offshore-grid concepts illustrate this development. They envisage offshore infrastructure serving multiple countries rather than a single national electricity project.

3. International Legal Framework

A. United Nations Convention on the Law of the Sea

The starting point for offshore electricity infrastructure is the United Nations Convention on the Law of the Sea (UNCLOS).

Different maritime zones generate different legal rights.

Territorial Sea

Within the territorial sea, generally extending up to 12 nautical miles from the baseline, the coastal state exercises sovereignty subject to international-law limitations.

Consequently, offshore electricity installations located in territorial waters are strongly subject to national permitting, environmental and construction legislation.

Exclusive Economic Zone

In the EEZ, the coastal state does not possess full sovereignty, but it has sovereign rights concerning natural resources and jurisdiction over certain activities, including installations and structures.

Article 60 of UNCLOS is particularly important because it recognises the coastal state's jurisdiction over artificial islands, installations and structures in the EEZ.

Thus, a state may regulate offshore energy infrastructure within its EEZ even though the EEZ is not equivalent to territorial sovereignty.

Continental Shelf

Offshore electricity infrastructure may also interact with the continental-shelf regime, particularly where installations are connected with seabed activities.

4. Maritime Spatial Planning

An offshore electricity hub competes for marine space with:

shipping;

fishing;

offshore oil and gas;

telecommunications cables;

military activities;

environmental conservation;

tourism;

other renewable-energy projects.

Consequently, legal governance requires marine spatial planning.

The European Union's maritime spatial-planning framework provides an important example. Maritime spatial planning attempts to coordinate different uses of marine space rather than allowing energy projects to develop independently.

For an offshore hub, spatial planning should identify:

hub location;

cable corridors;

exclusion zones;

shipping routes;

environmental protection areas;

connection points;

maintenance corridors.

5. Cross-Border Electricity Regulation

The defining characteristic of many offshore hubs is their cross-border nature.

Suppose a North Sea offshore wind hub receives electricity from offshore wind farms and connects:

Denmark,

Germany,

the Netherlands,

Belgium and

the United Kingdom.

The legal system must determine:

Which country's transmission rules apply?

Which market rules govern electricity trades?

Who allocates interconnection capacity?

Which country receives congestion revenues?

Which regulator approves investment?

Which law applies to disputes?

This creates a need for regulatory cooperation and harmonisation.

6. Ownership Models

Several ownership models are legally possible.

6.1 National Ownership

One state or its transmission-system operator owns the offshore hub.

This model simplifies ownership but becomes difficult where the infrastructure serves several countries.

6.2 Joint Ownership

Several transmission-system operators or governments jointly own the facility.

This requires detailed agreements dealing with:

capital contributions;

voting rights;

operational control;

liability;

maintenance;

revenue sharing;

insolvency;

dispute resolution.

6.3 Independent Infrastructure Company

A separate corporate entity may own and operate the hub.

Its legal status could resemble an independent transmission operator or infrastructure company.

This model may facilitate cross-border investment but raises regulatory questions concerning:

licensing;

tariff regulation;

market access;

competition;

corporate governance.

7. Transmission Regulation

An offshore hub should generally be treated as critical electricity infrastructure rather than simply as a generation project.

Transmission regulation determines:

connection rights;

access conditions;

tariffs;

congestion management;

system balancing;

reliability standards;

maintenance obligations.

Where a hub possesses natural-monopoly characteristics, regulators may need to impose third-party access and non-discrimination requirements.

8. Competition Law

Competition law becomes important where a hub controls a strategically significant transmission route.

Potential problems include:

discriminatory access;

preferential treatment for affiliated generators;

excessive transmission charges;

foreclosure of competing generation;

abuse of dominant position.

In the EU, Articles 101 and 102 of the Treaty on the Functioning of the European Union can become relevant, alongside EU electricity-market legislation.

An offshore hub operator therefore cannot necessarily favour one connected wind farm over another.

9. Environmental Regulation

Large offshore hubs can affect:

seabirds;

marine mammals;

fisheries;

benthic ecosystems;

marine protected areas;

sediment patterns;

navigation.

Environmental impact assessment is consequently central to legal governance.

A comprehensive environmental assessment should consider the cumulative effects of the hub, cables and connected wind farms.

This is particularly important because treating each wind farm and cable as a completely separate project may underestimate the environmental effects of the overall offshore electricity system.

10. Energy Islands and Multi-Purpose Interconnectors

A particularly important development is the multi-purpose interconnector (MPI).

A traditional interconnector connects two electricity systems:

Country A ↔ Country B

An offshore hub can create:

Wind farms → Offshore Hub → Country A
→ Country B
→ Country C

This transforms the legal character of the infrastructure.

The hub becomes simultaneously:

a generation-connection facility;

a transmission facility;

an international interconnector;

a market-coupling facility.

Consequently, traditional legal classifications may become inadequate.

11. Regulatory Jurisdiction

Jurisdiction is one of the most difficult questions.

Three jurisdictions may potentially overlap:

1. Coastal-state jurisdiction

The state where the hub is physically located may exercise regulatory authority.

2. Destination-state jurisdiction

Countries receiving electricity may seek to apply their electricity-market rules.

3. International jurisdiction

Where the facility lies outside territorial waters, UNCLOS and other international rules become relevant.

Therefore, offshore hubs require jurisdictional allocation agreements.

Such agreements should identify:

applicable law;

licensing authority;

safety regulator;

environmental regulator;

electricity regulator;

dispute-resolution mechanism.

12. Case Law

A. The M/V Saiga (No. 2) — ITLOS

The Saiga case is an important authority for understanding the distinction between coastal-state rights and broader maritime jurisdiction.

The International Tribunal for the Law of the Sea considered the extent of coastal-state jurisdiction under UNCLOS.

Although the case did not concern offshore electricity hubs, its reasoning is relevant because modern offshore energy infrastructure operates within overlapping maritime jurisdictions.

Legal significance: offshore energy governance must distinguish between sovereignty in territorial waters and more limited rights in maritime zones such as the EEZ.

B. Southern Bluefin Tuna Cases

The Southern Bluefin Tuna disputes demonstrate the importance of cooperation where activities have transboundary consequences.

The disputes concerned conservation rather than electricity infrastructure, but the underlying principle is relevant to offshore hubs: activities affecting shared or transboundary interests require cooperation between states.

Relevance to offshore electricity hubs: environmental impacts, marine spatial planning and infrastructure corridors can cross national boundaries.

C. MOX Plant Case (Ireland v United Kingdom)

The MOX Plant dispute is particularly relevant to transboundary environmental governance.

The dispute demonstrated the legal importance of information exchange, cooperation and environmental concerns where activities may affect another state's interests.

For offshore electricity hubs, this supports the importance of:

environmental information sharing;

cross-border impact assessment;

consultation;

cooperative monitoring.

13. EU Electricity-Market Case Law

A. Federutility and Others v Autorità per l'energia elettrica e il gas — C-265/08

The Court of Justice of the European Union examined state intervention in energy markets and the requirements governing public-interest intervention.

The case illustrates that electricity regulation must balance market principles with legitimate public-interest objectives.

For offshore hubs, similar questions can arise concerning:

regulated tariffs;

access obligations;

public-interest infrastructure;

security of supply.

B. Essent Belgium NV v Vlaamse Reguleringsinstantie voor de Elektriciteits- en Gasmarkt — Joined Cases C-204/12 to C-208/12

The CJEU examined national measures affecting electricity markets and the principles governing cross-border electricity trade.

The broader relevance is that national energy regulation cannot be designed entirely independently where it affects an integrated electricity market.

For offshore electricity hubs, this principle is particularly significant because the infrastructure itself is designed to facilitate cross-border electricity flows.

14. UK Offshore Energy Governance

The United Kingdom provides an important example because it has extensive offshore wind resources and operates an interconnected electricity system.

Relevant regulatory areas include:

offshore renewable-energy licensing;

transmission regulation;

marine planning;

environmental assessment;

electricity-market regulation;

interconnector licensing.

The UK's offshore wind development demonstrates that offshore energy infrastructure requires coordination between energy regulation and marine regulation.

15. Liability for Grid Failures

A major unresolved issue concerns responsibility for failure.

Suppose:

Offshore wind farm → Hub → Interconnector → National grid

If the hub fails, electricity supplies to multiple countries may be interrupted.

Potentially responsible parties could include:

wind-farm operators;

hub owners;

transmission-system operators;

cable operators;

maintenance contractors.

Contracts should therefore clearly allocate:

operational responsibility;

maintenance duties;

force majeure;

outage compensation;

consequential losses;

insurance;

cybersecurity liability.

16. Cybersecurity and Critical Infrastructure

Offshore electricity hubs will increasingly constitute critical energy infrastructure.

Their digital systems may control:

power flows;

circuit breakers;

protection systems;

market communications;

remote maintenance;

balancing.

Cybersecurity law must therefore address:

incident reporting;

minimum security standards;

supply-chain security;

access controls;

resilience testing;

emergency response.

A cyberattack against one hub could potentially affect several national electricity systems simultaneously.

17. Energy Security

Offshore hubs can increase energy-system resilience by diversifying electricity connections.

However, interdependence also creates systemic risks.

A single offshore hub connecting several countries could become a single point of failure.

Legal governance should therefore require:

redundancy;

emergency planning;

black-start capability where appropriate;

backup communications;

physical security;

system restoration protocols.

18. Tariffs and Revenue Allocation

An offshore hub creates complex economic questions.

Suppose Country A finances 40% of the hub, Country B finances 35%, and Country C finances 25%.

The legal framework must determine whether revenues are allocated according to:

ownership shares;

electricity flows;

transmission capacity;

congestion revenues;

usage;

regulated cost recovery.

A transparent formula is necessary to prevent disputes.

19. Public Participation and Local Communities

Although an offshore hub may be located far from the coast, coastal communities can be affected through:

fishing restrictions;

cable landfalls;

construction activity;

navigation changes;

visual impacts;

employment opportunities.

Therefore, meaningful consultation should form part of the licensing process.

20. India and the Future Legal Framework

For India, offshore electricity hubs could become relevant as offshore wind expands, particularly along the Gujarat and Tamil Nadu coasts.

Indian regulation would potentially involve:

Electricity Act, 2003;

Renewable Energy policy;

Central Electricity Regulatory Commission;

Central Electricity Authority;

Ministry of New and Renewable Energy;

maritime and environmental authorities;

transmission planning institutions.

India would need to develop specific rules concerning:

offshore wind-zone allocation;

offshore transmission;

multi-project connection;

hub ownership;

transmission tariffs;

marine spatial planning;

environmental assessment;

offshore grid security;

cross-border electricity trade.

The existing electricity framework can provide a foundation, but large multi-purpose offshore hubs may require more specialised regulations.

21. Principles for Effective Legal Governance

A future offshore electricity-hub framework should be based on several principles:

1. Clear jurisdiction

The law must identify which regulator has authority over each part of the infrastructure.

2. Regulatory cooperation

National regulators should cooperate through formal agreements.

3. Open access

Eligible generators and market participants should receive transparent and non-discriminatory access.

4. Environmental sustainability

Cumulative environmental effects should be assessed.

5. Security of supply

Hub design should incorporate redundancy and emergency arrangements.

6. Revenue transparency

Transmission charges and congestion revenues should be allocated according to clear rules.

7. Investor certainty

Long-term regulatory stability is essential for large capital-intensive projects.

8. Public participation

Affected communities and marine users should have meaningful opportunities to participate.

9. Cyber resilience

Cybersecurity should be treated as part of electricity-system regulation.

10. International cooperation

Cross-border offshore infrastructure requires treaty-level or regulatory agreements where national legislation alone is insufficient.

22. Conclusion

The legal governance of offshore electricity hubs represents a transition from national electricity regulation toward interconnected, multi-jurisdictional energy governance. Unlike conventional power plants or transmission lines, offshore hubs combine generation, transmission, interconnection, maritime infrastructure and electricity markets within a single system.

UNCLOS provides the maritime foundation, while national electricity legislation, environmental law, competition law and cross-border market rules provide additional layers of governance. Cases such as M/V Saiga (No. 2), the MOX Plant dispute and EU electricity-market decisions demonstrate broader legal principles concerning jurisdiction, cooperation, environmental protection and cross-border energy regulation.

The central challenge is therefore not simply building offshore hubs but constructing a coherent legal architecture capable of governing ownership, jurisdiction, environmental impacts, market access, liability, cybersecurity and international electricity flows simultaneously.

Future offshore electricity law is likely to move toward integrated offshore-grid governance, where states, regulators, transmission operators and private developers operate within coordinated legal frameworks rather than isolated national regimes.