Is hydrogen the ‘silver bullet’ for heating homes?

In November, Ofgem gave the green light to the H100 Fife project, a heating modification trial that will convert nearly 300 natural gas-powered homes to hydrogen fuel. The move comes after several recent publications suggest policy makers should think carefully about investing in hydrogen for heating. 

The timing of energy regulator Ofgem’s approval of modified network arrangements for the H100 Fife project could not have been better. 

As temperatures plummeted across the UK in December and households faced the stark choice of heating their homes knowing soaring energy bills are in the pipeline, the SGN development has been hailed by proponents as an important showcase project that will demonstrate hydrogen’s feasibility in providing a sustainable heating solution for the nation’s gas network.

National Grid argues that if the UK is to reach net zero carbon emissions by 2050, alternative low- or no-carbon energy sources must be considered; hydrogen, it adds, presents one of the most promising options for heating homes. 

According to the publicly listed utility, experts are optimistic that the wide-scale strategic switch from natural gas, which currently accounts for almost 85% of the fuel used for heating and cooking in UK homes, to hydrogen heating will start to happen over the next decade.

Supporters of the low-carbon fuel and its use for heating purposes argue that only small adjustments to current, fossil fuel boilers are required to enable hydrogen uptake. What’s more, a blend of fossil gas and hydrogen could be injected into the current network during the transition period without the need to make any changes to existing infrastructure. 

According to the Hydrogen Costs report produced by energy analysts Cornwall Insight for the MSC Charitable Foundation, and published in September 2022, the UK government has “proposed three milestones to expand the knowledge base on the role of hydrogen in heating”.  

The first is to develop a neighbourhood hydrogen trial by 2023, followed by a large hydrogen village two years later, and finally the possibility of a hydrogen town by 2030. As Cornwall Insights notes, the government is also considering whether to allow blending of up to 20% hydrogen into the gas network next year.

However, despite the UK government’s support for hydrogen to heat homes, several publications in recent months have challenged this position, with one notable and extensive review of international studies concluding that a number of other alternatives offer a better option than hydrogen in the supply of domestic heating.

Jan Rosenow, Managing Director at the European-based Regulatory Assistance Project, published an evidence review of 32 studies in the research journal Joule in September under the title “Is heating homes with hydrogen all but a pipe dream?”. 

In assessing the evidence, he concluded that none of independent studies, which were undertaken at the international, regional, national, state and city-level by a diverse range of organisations, such as research institutes, intergovernmental bodies and consulting firms, supported widespread use of hydrogen for heating.  

In fact, Rosenow’s conclusion was quite damning, noting that “existing independent research so far suggests that, compared to other alternatives such as heat pumps, solar thermal and district heating, hydrogen use for domestic heating is less economic, less efficient, more resource intensive, and associated with larger environmental impacts”.  

To start with, his in-depth review found that hydrogen for heating purposes produces higher energy system costs when compared to the alternative technologies – heat pumps, district heating and solar thermal – that deliver decarbonise space and hot water. The reason for this, he explained, is that green hydrogen (made via electrolysis) generates higher electricity needs than electrification via heat pumps.

He also notes from the comprehensive review that consumer heating costs – both the upfront and the running costs of heating systems – are higher for hydrogen. 

“There are uncertainties to what extent costs will change over time and how that will impact on consumer costs, but the evidence identified suggests that heating with hydrogen will be more expensive for consumers,” he concludes.

Another observation that he makes from the evidence review, albeit from the findings of a single study, is that hydrogen for heating “leads to higher environmental impacts, necessitates more energy supply infrastructure, uses more resources, and requires more land”. 

Rosenow also looked at how efficient hydrogen production and consumption is and concluded that “it takes about five times more electricity to heat a home with hydrogen than it takes to heat the same home with an efficient heat pump, either individually or as part of a district heating network”. 

Although the evidence review doesn’t support widespread use of hydrogen for heating, some of the studies he looked at did identify complementary roles such as in district heating and hybrid heating systems.     

Significantly, the Joule publication also highlights a number of supplementary reasons why policy makers should not prioritise hydrogen for heating.

The first is that there are more high-priority applications where hydrogen is needed such as replacing fossil fuels in high-temperature industrial processes and for long-term energy storage for electricity production. 

“Given the scale of hydrogen needed for those applications where few alternative decarbonisation options exist, it seems sensible to focus efforts in the heating sector on the roll-out of established technologies,” he advises.

Rosenow also warns that focusing on hydrogen for heating could result in a delay in other currently-available alternative clean heating technologies being deployed, especially as reducing carbon emissions requires urgent action.

“Hydrogen will play a critical role in the future energy system in areas where few or no alternatives for decarbonisation exist, but producing hydrogen is very energy intensive and it needs to be used where it makes most sense. Home heating has not been identified in independent research as an area where it should be used at scale,” Rosenow told Building Engineer.

“The danger is that rather than rolling out low-carbon heating and energy-efficiency measures the UK adopts a wait and see approach compromising its ability to meet the net-zero carbon emission targets. Meanwhile, other countries now move full steam ahead and stop installing new fossil fuel heating systems in only a few years’ time switching to proven technologies such as heat pumps, district heating, solar thermal and energy efficiency measures.”

The Cornwall Insight report also raises questions about the role of hydrogen for heating, and specifically warns about the costs to the consumer. 

Commissioned by MCS Charitable Foundation to compare the costs of blue and green hydrogen and their respective blends with natural gas, and based on projected gas prices from 2025, the report warns that hydrogen would cost 70-90% more than gas on average, resulting in huge energy bill rises for households over the next three decades. 

“While hydrogen does have a part to play in the decarbonisation pathway, through for example use in the industrial sectors and in the use of surplus electricity, current and forecast costs all show it is simply uneconomical to use a 100% hydrogen fuel for heating our homes,” said Jitendra Patel, Senior Consultant at Cornwall Insight and one of the report’s authors.

“We do, however, see benefits in accelerating the roll out of renewable generation to help bring down generation costs and we predict a near cost parity between green and blue hydrogen production methods by 2030 when using surplus electricity.”

Image credit | iStock