Hydrogen is seen as an essential part of the UK’s ambitious plan to implement the world’s first carbon-free gas network. Recognized as a zero or low-carbon alternative to natural gas, hydrogen has the potential to accelerate the decarbonization of the country’s gas supplies.
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One-third of the UK’s carbon dioxide emissions are generated from the gas used for heating and cooking at home. With 85% of Britain’s homes connected to the gas network, a significant change is needed to achieve net-zero emissions by 2050.
Without affecting the standard or level of heating at home, immediate and significant carbon savings can be expected by replacing, at least in part, some of the network’s natural gas with hydrogen.
Blending Hydrogen into the Gas Grid
At present, the hydrogen content in the UK’s gas network is limited by regulations to 0.1%. The Frontier Economics report on hydrogen blending published by Cadent states that this limit can be increased to a 20/80 blend of hydrogen/methane by volume without impacting gas pipelines or appliances. Increasing the hydrogen content to 20% could lead to an annual emissions saving of approximately 6 million tons of carbon dioxide – equivalent to removing 2.5 million cars off the roads.
With the 20% limit intended as a transitional arrangement towards a pure hydrogen or hydrogen/biomethane system in the future, ‘hydrogen-ready’ appliances are being prototyped through programs such as Hy4Heat.
Hydrogen Pilot Trials
The HyDeploy project was the first of its kind in the UK, where 20% hydrogen was injected into the private gas network at the Keele University campus. The project was carried out with approval from the Health and Safety Executive (HSE), which considered the blend to be as safe as the natural gas currently used in the UK. This live pilot successfully demonstrated the safety and technical case for hydrogen blending as the residents could use their existing appliances as normal without any adverse impact.
The next trial will see the 20% hydrogen mix introduced to the public network to demonstrate that hydrogen blending can occur safely at scale without disruption to end-users. Starting in 2021, the test area of Winlaton will undergo trials with this mix for around 10 months. The results from this demonstration will be critical in helping the government make strategic decisions on the long-term role of hydrogen in the UK’s energy mix. Subject to successful tests and trials, the UK government and HSE aim to increase the hydrogen blend limit on the network to 20% by 2023.
Technical Challenges of Introducing Hydrogen into the Gas Network
Further development and testing will be required to safely introduce hydrogen into the UK’s gas network in larger quantities. Cadent and Frontier Economics’ report outlines the necessary changes needed for the 284,000-km gas network to deliver hydrogen and biomethane. The report also sets out the steps that key stakeholders will need to take before blending can be implemented on a larger commercial scale.
The report emphasizes the safety obligations that hydrogen producers and network operators have. The HyDeploy projects play a part in establishing safe operating parameters for residential settings, but further work will be required to understand what is acceptable to industrial users.
Generating Demand for Green Hydrogen
Green hydrogen is produced through the electrolysis of water using zero-carbon or renewable electricity. Although it has been identified as a sustainable way of producing zero-carbon gas, green hydrogen is not currently produced at scale.
The high cost associated with green hydrogen production has historically been one of the biggest obstacles to mass adoption in the energy market. However, a study by Wood Mackenzie suggests that this cost will reduce by up to 64% by 2040.
Ben Gallagher, senior research analyst of Wood Mackenzie and report author, states: “On average, green hydrogen production costs will equal fossil fuel-based hydrogen by 2040. In some countries, such as Germany, that arrives by 2030. Given the scale up we’ve seen so far, the 2020s is likely to be the decade of hydrogen.”
Rising fossil fuel prices will boost green competitiveness, further strengthening the case for this technology in the coming years."
Ben Gallagher, senior research analyst of Wood Mackenzie and report author
Green hydrogen must be cost-competitive to realize its potential as an emissions-free alternative. Achieving the milestone of successfully blending hydrogen at higher proportions into the gas grid could be critical to generating a reliable and significant source of demand for hydrogen producers. Not only could this promote investment in hydrogen production, but the supply-side support would also improve production costs through a robust supply chain. The government and industry will have a significant role in stimulating this demand for hydrogen production and establishing its place in the UK energy mix.
It is clear that hydrogen has great promise in enabling a decarbonized future, but the challenges around adapting existing infrastructure and scaling up need to be addressed. Moreover, the switch to hydrogen will not happen overnight. It is recognized that a complete evaluation of the costs and practicalities of implementation will be a huge but necessary undertaking for a robust hydrogen economy to become a reality.
References and Further Reading
Wood Mackenzie (2020). Green hydrogen costs to fall by up to 64% by 2040. [Online] Available at: https://www.woodmac.com/press-releases/green-hydrogen-costs-to-fall-by-up-to-64-by-2040/ [Accessed on 17 Mar. 2021].
Energy Networks Association (2020). Hydrogen blending – what is it and why does it matter? [Online] Available at: https://www.energynetworks.org/newsroom/hydrogen-blending-what-is-it-and-why-does-it-matter [Accessed on 17 Mar. 2021].
HyDeploy (n.d.). HyDeploy North East. [Online] Available at: https://hydeploy.co.uk/winlaton/ [Accessed on 17 Mar. 2021].
National Grid (2020). Exploring ways to create the world’s first zero carbon gas network. [Online] Available at: https://www.nationalgrid.com/stories/journey-to-net-zero-stories/exploring-ways-create-worlds-first-zero-carbon-gas-network [Accessed on 17 Mar. 2021].
HM Government (2020). Powering our Net Zero Future. [Online] Available at: https://assets.publishing.service.gov.uk [Accessed on 17 Mar. 2021].
Frontier Economics (2020). Hydrogen Blending and the Gas Commercial Framework. [Online] Available at: https://cadentgas.com [Accessed on 17 Mar. 2021].