As UK offshore wind pushes further into the North Sea, the territorial limits of patent law are creating a blind spot that developers and innovators can no longer afford to ignore, writes Lawrence Paleschi.
The UK offshore wind sector is expanding at a remarkable pace. Allocation Round 7 awarded a record 8.4 GW of new capacity, and the 2026 Hamburg Declaration has committed the UK and its EU partners to delivering 100 GW of offshore wind in the North Sea by 2050. The engineering ambition is significant. But as the industry pushes further offshore into deeper, windier waters, it is quietly running into a legal problem that developers may overlook: the territorial limits of patent protection.
A gap in the law
Patents are territorial rights. A UK patent protects an invention across the UK landmass, the Isle of Man, and the country’s territorial waters – a zone extending just 12 nautical miles from the coast. The problem is that the most commercially significant offshore wind developments now sit well beyond that line. Dogger Bank, set to become the world’s largest offshore wind farm, lies more than 50 nautical miles off the Yorkshire coast. While it falls within the UK’s exclusive economic zone (EEZ), the EEZ is not equivalent to territorial waters when it comes to patent enforcement – and the legal consequences of that distinction became starkly apparent in a 2022 High Court case between Siemens Gamesa and General Electric.
Siemens alleged that GE’s Haliade-X turbines, assembled at Dogger Bank, infringed its UK patent. The patent was ultimately found invalid, but the judge went further, ruling that even had it been valid, the offshore assembly would have fallen outside the territorial scope of the UK Patents Act 1977. The court also rejected the argument that anchoring turbines to the seabed should attract the extended protections afforded to oil and gas operations under the Petroleum Act 1998. Renewable energy, it seems, occupies a more legally exposed position than its fossil fuel predecessor.
Drafting patent claims that can actually be enforced
For developers and innovators, this ruling sets a clear precedent. If patent claims cover a fully assembled turbine or complete offshore installation, and that assembly takes place beyond the 12-mile limit, the patent may offer little practical protection, regardless of how inventive the underlying technology is.
The solution lies in how patent claims are drafted. Rather than protecting the assembled whole, patent strategies should focus on individual, modular components: a turbine blade geometry, a subsea battery casing, a mooring system, or a specialist gearbox. These parts are typically manufactured in the UK or imported through UK ports – and it is at that point in the supply chain that infringement can be established under the Patents Act 1977. A ‘kit of parts’ approach works on the same principle: by framing claims around components intended for offshore assembly, rights holders create enforceable protection that applies the moment those parts move through UK territory.
Green hydrogen and energy storage
For emerging offshore energy storage technologies, such as green hydrogen, the IP challenge can take a different form. As developers co-locate electrolysers with floating wind arrays and transport hydrogen back to shore, protecting the underlying hydrogen production process becomes commercially important. Here, UK patent law offers a route: the importation of the direct product of a patented process constitutes infringement, even where that process occurs outside UK territory. A company with an inventive offshore hydrogen production method could, in principle, enforce its patent at the point the gas arrives at a UK terminal.
Subsea battery systems raise similar considerations, potentially in relation to the electricity discharged from the battery. As with wind turbines, significant value may also lie in protecting subsystem components, such as in thermal management and pressure compensation systems, through tightly drafted claims that attach liability onshore, where enforcement is straightforward.
Why trade secrets are not always the answer
Trade secrets may seem like an appealing alternative to registered IP, given that the remoteness of offshore installations makes reverse engineering unlikely. In practice, however, this approach is fragile. Complex offshore systems require extensive supply chains, with component manufacturers, contractors, installation and maintenance crews each representing a potential point of knowledge leakage. A trade secret also cannot be enforced against a competitor who independently develops the same innovation. For core technological developments, formal IP registration is the more reliable foundation.
IP strategy as a competitive necessity
The Hamburg Declaration has placed the North Sea at the centre of Europe’s long-term clean energy ambitions, and competition over the underlying technology will only intensify. For innovators in this sector, getting IP strategy right from the earliest stages of product development is as important as the engineering itself.
Patents remain powerful tools, but only if they are built with a clear understanding of where in the supply chain protection can actually be enforced.
