Switching to low carbon building heating is vital in reducing the Island’s greenhouse gas emissions and achieving net zero by 2050. However, the affordability and practicality of heating options must be considered as there is a range of potential alternatives to fossil fuel heating systems, such as air and ground source heat pumps, direct electric and infra-red heating, biomass and liquid biofuels. There is much discussion in the press and on social media about hydrogen, it’s helpful to set out where it sits in the Island’s future heating mix.
In deciding the Island’s policy, we must weigh up several factors. These include the up-front cost of low carbon heating systems, how much they will cost consumers to run, and importantly the likely availability of future fuel sources. We also need to consider the social impact of decisions we take, particularly on low income and other vulnerable customers.
So, where does hydrogen fit in?
Hydrogen may appear superficially attractive because of the relatively similar technology type that exists in most of today’s heating systems; however, there are a number of important factors to consider when evaluating where hydrogen may fit into the decarbonisation of the Isle of Man’s building heating sector.
The fuel’s availability and competition for its use
Some argue that hydrogen is the most abundant element in the universe. Whilst this is correct, it is misleading when it comes to practical applications. It does not exist naturally anywhere on earth in useable or economically extractable form. Instead it is chemically bonded within other chemical compounds, the most accessible of which are water and natural gas. Both of these require considerable energy, and loss of efficiency, in order to extract hydrogen at useable purities.
Hydrogen is therefore not available today at sufficient quantities, at sufficiently low a price, or with a low enough carbon footprint in its production for it to feature in our immediate options for decarbonising heat. Moreover there are considerable uncertainties over its future likely cost of production.
The UK government is less certain about the role for hydrogen in heat, identifying in their pathway it will currently play a small role of 5% for building heating[1]. However recent research[2] has raised substantial concerns around its efficiency, cost and likely availability particularly in relation to building heating. Academic literature also sows considerable doubt on its use[3].
A UK Government Minister also recently announced the proposed trial of the first Hydrogen Village in Whitby would not now proceed due to opposition from residents[4]. The UK Government also recognises that production of low carbon hydrogen will require long-term subsidies to bring its high production costs in line with those of high carbon fuels, and had proposed legislation to enable this[5]. The Secretary of State has recognised that it would be undesirable, as originally intended, to fund these subsidies with a levy on gas bills, and has publicly announced scrapping of plans to do so[6].
In 2022, the Renewable Heating Scenarios for the Isle of Man indicated that hydrogen would be costly and unlikely to be readily available or affordable in the timeframe necessary for the Isle of Man to meet our climate goals, and this remains true 18 months after the report.
In particular, there are some applications that require the high temperatures that can realistically only be provided by combustion, where alternatives such as heat pumps cannot service this need. It is therefore likely that there will be intense competition for a limited supply of hydrogen production, with these high temperature applications being willing to pay considerably more than consumers can realistically be prepared to for domestic heating.
For example, Michael Liebreich’s ‘hydrogen ladder’, published by BloombergNEF, looks at hydrogen’s potential uses and where it should be prioritised – with highest priority assigned to uses for which no low carbon alternatives currently exist. This shows that hydrogen is better suited to high temperature industrial applications and certain types of transport and much less suitable for building heating.
The US also released its hydrogen strategy this month focusing it on these higher value, industrial sectors [7].
Current State of Technology Development
Whilst in theory hydrogen can be used in a similar way to natural gas in boilers because it burns at a high temperature, only prototype boilers have so far been developed. Although there is considerable research and development investment by the main manufacturers, no major manufacturer yet has a 100% hydrogen boiler as a production model that is available widely at a cost comparable to the mass market for gas boilers.
A number of boiler manufacturers market some appliances as ‘hydrogen ready’, but it is important to understand this does not mean they can burn hydrogen – it means that they are designed so they can be converted in the future to do so with a number of component changes which can take place at relatively low cost.
Without the availability of hydrogen fuel at a competitive price for the foreseeable future, consumers need to be aware that a home fitted today with a ‘hydrogen-ready’ boiler will likely only natural gas during its useable lifetime, and it is probably it will need to be replaced well before hydrogen starts to become readily and cheaply available.
A recent Which? article cites that hydrogen for heating is far from guaranteed to land consumers with an economical, comfortable deal and warns that most ‘hydrogen ready boilers’ are actually only suitable for a hydrogen blend[8].
Hydrogen isn’t just a straight swap for natural gas either: the molecules are smaller, which means it’s more difficult to contain and upgrades to existing infrastructure could be needed to guard against leaks along with some retrofit, safety requirements in homes, such as venting.
Hydrogen leaking can also be bad from a climate perspective[9]. Hydrogen isn’t a greenhouse gas but it does have an indirect warming effect that will reduce some of its climate benefit relative to CO2[10].
Not our best option in terms of efficiency
Over 95% of world’s hydrogen supply is currently produced using the ‘steam methane reforming’ process, which utilises the burning of fossil fuels resulting in climate change causing greenhouse gas (GHG) emissions.
Green hydrogen, produced using electrolysis, can be emission free but it’s much more expensive so much less common.
Hydrogen is also not the most efficient way of heating our buildings. As per the visual below, efficiency is lost at every stage, from production to final use, meaning that the heat provided to the home by hydrogen is far less than the energy put in at the beginning of the process. By contrast, heat pumps can provide up to five times the efficiency, by transferring heat from the surrounding air or ground to our homes. This means more heat for the same amount of energy and makes heat pumps a better choice for home heating. More heat for less energy means lower costs too.
So, hydrogen isn’t the best option for home heating in terms of cost, availability, efficiency or emissions. Heat pumps, which are already widely available, outperform it on all these criteria.
Source: Committee on Climate Change: “Hydrogen in a Low Carbon Economy”, November 2018, Figure 1.2, page 26: https://www.theccc.org.uk/publication/hydrogen-in-a-low-carbon-economy/
With UK trials ongoing, albeit now at a lower scale than originally thought, the Climate Transformation board are keeping abreast of outcomes in this area and are developing the Isle of Man’s heat strategy in light of findings.
However, evidence is mounting that there are big challenges and increasingly it looks like hydrogen for use in buildings isn’t a practical solution as supported in a detailed study in our Manx context by consultancy firm Gemserv.
References:
[1] https://www.theccc.org.uk/wp-content/uploads/2020/12/The-Sixth-Carbon-Budget-The-UKs-path-to-Net-Zero.pdf).
[2] https://www.cornwall-insight.com/wp-content/uploads/2022/09/MCS-Insight-Paper-Hydrogen-Sept-2022.pdf?utm_source=website&utm_medium=website
[3] https://www.sciencedirect.com/science/article/abs/pii/S2542435122004160
[4] https://twitter.com/MartinCallanan/status/1678450332857188353?s=20
[5] https://www.gov.uk/government/publications/energy-security-bill-factsheets/energy-security-bill-factsheet-hydrogen-and-industrial-carbon-capture-business-models
[6] https://www.theguardian.com/politics/2023/jun/24/shapps-signals-u-turn-planned-hydrogen-levy-energy-bills
[7] https://www.hydrogen.energy.gov/pdfs/us-national-clean-hydrogen-strategy-roadmap.pdf
[8] https://www.which.co.uk/reviews/boilers/article/hydrogen-boilers-what-you-need-to-know-afWnI9h2Bory
[9] https://www.nature.com/articles/s43247-023-00857-8
[10] https://www.gov.uk/government/publications/fugitive-hydrogen-emissions-in-a-future-hydrogen-economy