Project Summary

This project aims to develop technologies to enable the existing gas transmission network to supply hydrogen as a low-carbon energy source to heat customers with the most rapid deployment. The project directly addresses the need to work with partners on how deployment of low-carbon heating solutions can be better coordinated to minimise gas network constraints at lowest economic cost.

The ability to coat network components will increase lifetime and enable operation of network at parameters optimised for the transmission of hydrogen.

The National Transmission System (NTS) in the UK supplies gas to distribution networks whom in turn supply gas to 23 million homes in the UK as their primary heat energy source. The network varies in age, condition and material composition which leads to variation in its suitability for hydrogen. Some NTS materials may be prone to hydrogen damage thereby reducing the asset lifetime and/or necessitating the adoption of sub-optimal operating parameters. Barrier coatings on the internal surface of the asset can mitigate this by drastically reducing hydrogen uptake. In enabling more of the existing NTS network to be utilised for transporting hydrogen, a fuel with a third the energy content of methane, we are providing resilience and storage, rather than relying on transient production.

This project led by National Grid Gas Plc (GT&M) will build on the outcomes of the Hydrogen Barrier Coatings for Gas Network Assets SIF Discovery Project. Discovery identified high potential candidate hydrogen barrier coating materials and several process options for surface preparation and deposition but with a key challenge of deploying the coatings inside the online assets.

The Alpha project will look to develop innovative solutions to deposit barrier coatings onto prioritised gas network assets such as line pipe and welds as well as above-ground assets. In-situ deposition techniques involving pipeline inspection gauges (PIGs) and robotics will be investigated alongside a review of the opportunities and associated costs with undertaking the coating process offline. A cost-benefit analysis of these re-purposing technologies will be considered alongside replacement with new "hydrogen-ready" assets.

The project partners are experts in the field of pipelines (GT&M), metallic coatings (Ultima Forma Ltd) and pipeline operations (ROSEN). As operator of the NTS, GT&M will provide the user requirements for all technologies developed as well as providing material samples and assets to trial. Building on their work within the Discovery phase, Ultima Forma will use their knowledge of coating materials and techniques to determine the most suitable technologies for individual asset use cases. ROSEN will join the project as experts in in-line robotic technologies and will lead activities on in-situ coating deposition.

The re-purposing of existing pipelines for hydrogen transmission is of interest worldwide, furthermore, this technology has benefits for all hydrogen storage vessels and could be applied to several applications above and beyond onshore pipeline application. In-situ barrier coating technologies may also have additional applications, for example, CO2 transport for carbon capture, utilisation and storage (CCUS) and chemical industries, potentially reducing costs, installation time and disruption, and environmental impacts of installing new pipeline.

The customers of the technologies developed in this project are primarily gas networks that look to inject hydrogen into metallic pipelines that are impacted by hydrogen embrittlement, however, this could be expanded to any user of susceptible materials in a hydrogen environment. The users of the technology will be in two parts: the coating manufacturer and application owner, at present our project partners Ultima Forma and ROSEN cover these roles respectively. We have developed a knowledge of both the customers and users requirements of the system through Discovery and will continue this in the Alpha phase.

Innovation Justification

The National Transmission System (NTS) consists of 7654km of buried pipes and values below ground and auxiliary and service units above ground. All of these components have been designed for natural gas transportation and some are potentially vulnerable to failure from hydrogen embrittlement. This project supports the re-purposing of these assets to distribute hydrogen by protecting them from hydrogen permeation and therefore extending their lifetime and avoiding failure, focusing on the most vulnerable components first but considering the network as a whole.

Hydrogen damage of assets is a risk that requires mitigation for safe transmission of hydrogen. Current practices involve operation at lower pressures than currently utilised for natural gas transmission, however, such strategies drastically reduce the operational efficiency of the network compromising its ability to deliver the required energy to end-users. To overcome this energy deficit, new pipeline might need to be installed at significant cost to the consumer. The application of coatings to significantly reduce hydrogen permeation and thus damage, could enable safe operation at optimal gas pressures and velocities.

Our solution is to apply a thin metallic coating to the inside surface of the existing NTS assets, using a material that is not susceptible to hydrogen embrittlement. There are currently no commercially available in-situ coating deposition technologies for transmission network assets and presents a challenge when considering the lack of ability to access underground assets with many km between above ground installations. This project therefore represents a novel approach to the re-purposing of pipeline for hydrogen transmission that potentially has applications wider than the UK.

Discovery identified candidate coating materials, processes and at-risk gas network assets; however, significant technical challenges remain relating to the deposition of such coatings on existing assets. The Alpha phase will investigate in detail the coating requirements which will enable coating material selection and detailed development of suitable deposition technologies. A test programme of hydrogen permeability measurements and durability testing will provide data to determine the level of protection from hydrogen and indicate the steps required to maintain this protection through the networks lifetime. As well as validating coating performance the Alpha phase will focus on designing a process for economically feasible in-situ deposition.

If this project is not undertaken the ability to re-purpose the existing NTS for hydrogen could be compromised. This would have a knock-on effect for the large-scale, rapid deployment of hydrogen as new transmission pipelines would need to be built at significant cost to the consumer. Additionally, the long timeframes associated with the installation of new pipeline would impact the rate at which the UK can decarbonise, extending the duration of reliance on natural gas, making it more difficult to achieve the UK's committed net zero obligations.

In Discovery the key drivers for the installation of new assets were identified along with the key cost drivers for re-purposing of existing assets via the use of barrier coatings. The Alpha phase will expand on this work to ensure the re-purposing solutions deliver value for the consumer. There are expected environmental benefits to re-purposing rather than installing new equipment, including reduced CO2 impacts from manufacture and installation of new equipment, plus minimal impact to the countryside and local communities as a result of utilising existing assets. Consequently, there is a strong business driver to find solutions to re-purpose as many of the existing assets as possible.

This activity cannot be funded through business as usual as it is solely related to future hydrogen transmission. Furthermore, this project addresses significant technical barriers and as such would be deemed a high-risk, high-reward project which are best supported through Strategic Innovation Funding.

Benefits

The scale of hydrogen demand in the UK is ever growing with a move from the Net Zero Strategies (Oct 21) target of 5 GW of green and blue hydrogen by 2030 to the most recent Energy Security Strategy (Apr 22) target of 10 GW of green and blue hydrogen by 2030 across industry, transport, power and potentially heat. In order to meet this target we must connect producers and users of hydrogen to enable a fast transition from natural gas to hydrogen. Re-purposing assets is the most efficient method of doing this both in time and cost.

Direct project benefits:

Economic: Elimination of hydrogen permeation into the asset material, therefore eliminating the effect of hydrogen on the asset materials and extending the lifetime of the assets
Economic: Reduction in the asset replacement required prior to injection of hydrogen
End User & Economic: Extension of asset lifetime and reduction maintenance intervention
Consumer: Reduction in consumer costs through the transition and into Net Zero
Government: Developing UK capability, skills and competencies for net zero solutions, providing significant opportunity for export
Government: UK technology solutions development increasing the value of UK industry, encouraging inward investment into the UK hydrogen economy
Other hydrogen enabling benefits;

Environmental: Utilising existing gas assets with hydrogen for domestic users prevents the installation of new significant investment systems and time delays for net zero
Safety: Prevents having to transport hydrogen above ground, eliminating the likelihood of transportation accidents
Environmental: Enabling hydrogen to be distributed through the gas pipeline network will allow the market for industrial and residential products that run off hydrogen to be both feasible and enter the market at a competitive price because the cost of transition to blended gases running in the network will be minimised.
Environmental: The CO2 saving is substantial if the hydrogen is produced by renewable energy (green hydrogen), further reducing the countries reliance on fossil fuels and pulling demand for more renewables.
Consumer: Enables a supply of hydrogen to domestic users and with upgrades to existing gas boilers, maintains the market for use of gas networks and existing central heating systems - reducing costs for consumers
Resilience: The ability to link many producers and users together across the country enables resilience against a variable production source and provides storage for the UKs energy
Benefits will be measured through the reduction in hydrogen permeability and therefore hydrogen embrittlement in our pipelines leading to a lifetime and safety case where assets no longer require replacement. Our calculations seen in the appendices consider the cost to re-purpose a system vs the cost for a new installation. Through the Alpha phase we will also measure the total cost of doing nothing vs coatings vs new pipelines to provide insight into the optimum option.

The following potential Alpha impacts were identified in Discovery, these impacts will be considered against the solutions to ensure success of the project:

A number of candidate metal barrier coatings are available which would protect assets from hydrogen
Specific asset features could be more susceptible to hydrogen (welded joints). Feasibility of targeted coatings which would also save cost and improve feasibility will be considered in Alpha.
The surface conditions of existing in-service assets vary widely due to the length of service and maintenance regimes. We therefore identified different surface preparation methods to ready the area for a barrier coating.
A variety of assets exist on the network. Reviewing these assets on site the project team were able to identify which ones would be possible to protect and which ones would need an alternative solution, further consideration to be made in Alpha.