Today, hydrogen, a colourless, odourless, tasteless, flammable gas, is mainly used as a feedstock for the chemical industry.

Following the publication of the UK Hydrogen Strategy in August 2021 and the outcome of COP26 meeting of world leaders the following November, hydrogen’s applicability looks set to be expanded.

In the light of looming longstops on various carbon-intensive technologies and stricter carbon reduction commitments, policymakers and pipeline operators need to urgently consider what will be required to make hydrogen part of the UK’s cleaner energy mix from a transmission perspective.

The practical aspects

20% = 6.66%

National Grid has created its offline hydrogen ‘FutureGrid’ research facility in Cumbria with six project partners to look at the feasibilities of producing, transporting and supplying customers with a fuel composition of between 2% and 100% hydrogen.

Indications are that up to 20% hydrogen mix seems compatible with existing systems, both in terms of the UK’s National Transmission System (NTS) infrastructure and from the end user’s perspective.

But as hydrogen has three times greater volume than natural gas, a 20% hydrogen mix only adds up to a 6.66% reduction in traditional fuel use/capacity.

This means that, in the long term, relying on the UK’s existing NTS volume is unlikely to allow hydrogen fuel supply to be scaled up to the levels envisaged to meet emissions reduction targets without significant other non-pipeline transported power sources.

If the long-term goal is to increase the UK’s piped gas mix to 100% hydrogen, it is not yet clear how this could be achieved without significant new infrastructure.

Teaching an old network new tricks

Repurposing the UK’s ageing gas supply network (including the NTS) to accommodate hydrogen will mean ironing out a number of issues with the existing network.

The bulk of the subterranean gas pipeline infrastructure that forms the basis of the UK’s NTS is made of steel and was installed between 1940 and 1970.

While anti-corrosion cathodic protection and new monitoring technologies have kept this network in far better condition than could have been initially anticipated, high hydrogen concentrations speed up degradation by making the pipes more brittle and prone to cracking.

Hydrogen’s low density, increased leakage risk and high flammability also makes transportation and storage an additional headache from a transmission and liability perspective.

In an industry typically reliant on self-insurance, pipeline operators will need to consider whether self-insurance will be acceptable for a fuel makeup including hydrogen and, if not, what sort of insurance the market will be prepared to offer and on what terms.

If it becomes impossible to obtain insurance on reasonable terms, the UK government may set up a scheme (similar to Pool Re for terrorism) to ensure insurance cover is available to underpin national policy goals.

Assuming transmission of hydrogen is permitted by the relevant land rights, existing pipelines could be ‘re-lined’ from the inside using ‘PIG’ technology (a device that can travel along a pipeline).

This would have the significant advantage that further land rights are unlikely to be needed to allow the pipelines to carry hydrogen. However, this will be a huge challenge, given that traditional PIGs are not able to access all parts of a standard pipeline network. Some operators are looking at nano- and swarm technology to bridge this gap.

Other (land rights-dependent) options include upgrading pipelines section by section (likely only to be suitable for small stretches) by inserting a sheath or slightly smaller diameter pipeline into the existing infrastructure.

Land rights: Considerations for existing pipelines

Before considering any change or upgrade to an existing pipeline system to accommodate hydrogen, the operator must check its existing land rights (typically contained in a lease, deed of easement or wayleave) to see whether the transmission of hydrogen is permitted.

The deeds covering land rights often contain general indemnities/covenants regarding the use of potentially hazardous or explosive materials, which need to be checked as a continued breach could bring about the forfeiture or termination of that right.

Often, fuel lines were laid in the same trench by different operators with overarching cooperation agreements covering the sharing of easements and diversions etc., which may not be suitable for hydrogen lines.

Any access or intrusive works plans will also need to be checked against permitted rights along with permitted working widths and notice requirements.

Typically, a pipeline will have land rights on similar terms for each of its ‘legs’, with exceptions for special category landowners such as railway land, National Trust land, parks and roads.

Any gaps in the land rights should be ‘plugged’ before a project goes live to minimise the risk of third party challenge on the basis of trespass.

Fuel lines usually have a (sterilised) easement width of six metres within which the landowner must not carry out any intrusive works. This may not be suitable for hydrogen pipelines, which will require wider easements due to the elevated risks associated with transporting hydrogen.

Producing and transporting hydrogen will need more (and potentially larger diameter) pipelines than the UK currently has in place. The classification of the hydrogen (green, grey or blue, referring to its method of production and ‘cleanliness’ in emissions terms) will partly determine what sort of infrastructure is required.

In an ideal world, the UK would leap straight to ‘green hydrogen’ via electrolysis, requiring only water and renewable electricity to produce hydrogen and oxygen (potentially only requiring the one pipeline).

However most hydrogen production is ‘grey hydrogen’ made with steam-methane (from natural gas) reforming, which produces hydrogen and CO2 (which means extra pipelines).

If grey hydrogen is coupled with carbon capture technology, where the CO2 is captured and stored to produce ‘blue hydrogen’, the CO2 will need to be transported away, either in gaseous form or at high pressures as a dense or supercritical phase fluid (which will require further infrastructure).

Land rights: considerations for new pipelines

Setting aside questions of how to fund construction of a vast new network of pipeline infrastructure and where to find the pipeline engineers and contractors for contemporaneous projects, it is reasonable to ask why operators can’t simply build new pipelines.

In simple terms, the answer is ‘land and planning law requirements’.

Large scale (over 16km) linear projects almost always require compulsory powers to ensure the requisite land/rights can be vested in the project within the required time frame.

There are various mechanisms to achieve this, including Development Consent Orders (DCOs). DCOs can be granted in respect of Nationally Important Infrastructure Projects (NSIPs) for large scale projects falling into one of five general categories (energy, transport, water, waste, water and waste).

Such projects must fulfil the public interest criterion and applications have to be submitted to the Planning Inspectorate (PINS) for determination by the Secretary of State for Business, Energy and Industrial Strategy.

To apply to a pipeline project, a DCO must relate to a cross-country pipeline within the meaning of section 235(1) of the Planning Act 2008 and section 66 of the Pipe-Lines Act 1962, and be a pipeline whose length will exceed 16.093km.

This approach requires the acquiring authority to show it has done all it reasonably can to obtain the private agreement of each of the linear landowners affected before compulsory rights can be granted.

Depending on the scale of the project, applicants should factor in at least two years’ (but ideally more) lead-in time to consult land agents and legal practitioners well before that point to ensure a smooth process.

New onshore pipelines greater than 16km in length will also require a Pipeline Construction Authorisation (PCA) under the Pipe-Lines Act 1962 from the Secretary of State for Business, Energy and Industrial Strategy.

For smaller pipeline projects under 16km, consents can be obtained via the Town and Country Planning Act 1990.

Other relevant legislation

At present, hydrogen falls within the ambit of the Gas Act 1986, however there will likely need to be hydrogen-specific legislation (currently it is not permitted to add more than 0.1% hydrogen to the NTS, so legislation would need to change to allow this to happen).

The Control of Major Accident Hazards Regulations 2015 are relevant to the storage of hydrogen and are designed to reduce the risks of major accidents, associated with the handling of dangerous or hazardous substances.

Applicability depends on the operator’s tier status. Lower tier operators are required to document a Major Accident Prevention Policy. Top tier Control of Major Accident Hazards (COMAH) operators are required to produce a full safety report demonstrating that all necessary measures have been taken to minimise risks to the environment and local populations.

The Planning (Hazardous Substances) Regulations 2015 will also be relevant to storage of over two tonnes of hydrogen.

The Pipeline Safety Regulations 1996 govern, among other things, the safe design, integrity, installation, operation and emergency and shut down protocols relating to pipelines as well as decommissioning (with particular requirements for Major Accident Hazard Pipelines) and will need to be consulted in detail for any proposed project.

What next?

Given the dense habitation of the UK, any significant upgrade to its energy distribution network will likely require significant new infrastructure, which can be accommodated under existing compulsory acquisition frameworks, albeit there is also the possibility that existing legislation will be repurposed – for example, the New Roads and Street Works Act 1991 to allow fast-track consenting under public roads.

In any event, given that mechanisms to obtain new rights by compulsion have a typical lead time of at least one-to-two years, it is expected that the government will also need to turn its attention very quickly to the concept of a fast-track approval of repurposing existing assets to bridge that gap.

Operators will of course be mindful that any new energy project is likely to encounter opposition. In that case, they may also want to consider deploying an injunction against the world at large/persons unknown to protect land and commercial operations from acts of trespass and interference.

Such injunctions have been successfully deployed in the energy sector to protect projects from anticipated, and pre-empt, unlawful acts.

This article was authored by Emily Tetley-Jones, a real estate director and pipelines specialist at Fieldfisher.