Hydrogen boilers could cause four times as many explosions as gas

Safety fears as government-backed assessment finds the alternative fuel could spark as many as 39 blasts a year

So declared the headline to a Telegraph article on 4th August, and it was far from being alone in headlining with the “four times as many explosions as gas” theme. But was it justified? And what was behind it?

In 2017 the Department for Business Energy & Industrial Strategy (BEIS) appointed Ove Arup & Partners to be the programme managers for the Hydrogen for Heat Programme. As is now standard in the ongoing infantilisation of debate and dumbing-down of standards everywhere, it is to be known as Hy4Heat. The task of the programme managers was:

to establish if it is technically possible, safe and convenient to replace natural gas (methane) with hydrogen in residential and commercial buildings and gas appliances, to enable the government to determine whether to proceed to community trial.

In fairness, the programme managers have not produced a dumbed-down piece of work. The reporti appears to have been published on (at least it bears that date) 1st May 2021, but (short-lived) interest in it in the mainstream media seems to have been limited to the last few days. It runs to 144 pages, and a detailed analysis is beyond the scope of a short article here.

Wisely, the decision seems to have been taken to make the safety assessment on the basis of:

a two storey, masonry-built, terraced house with a basement and a loft conversion. This type of property has been selected because it comprises the single largest proportion of houses in the domestic housing stock in Great Britain, and is considered to be one of the most susceptible forms of construction in relation to gas explosion risks in domestic properties. This is because they are, in general terms, the least robust, due to historic or non-existent building regulations being used in the design and construction. They are often of unknown quality and could include substantial owner/occupier modification. They are also the type of home where historically the majority of deaths and injuries have occurred and where the differences in properties between methane and hydrogen indicate that the risks from hydrogen by comparison with methane are likely to be exacerbated.

The report considers the risks from fires and explosions, and doesn’t consider the risk from carbon monoxide (CO) poisoning, since CO is not a waste product of hydrogen. This is one area where hydrogen is safer than natural gas (though the report does point out that the last CO fatality in the UK was in 2015).


The report estimates an average, for the entire British population, of nine explosions (it calls them “ignited events”) per annum from natural gas, excluding any incidents which might be expected to arise from misuse of appliances (such as leaving a gas hob on but unlit).

By alarming contrast, it estimates, for the same population, an average of 39 “ignited events” per annum. They point out that they predict a greater number of very large explosions than observed in practice from historical incident reporting. The number of injuries predicted from hydrogen gas explosions are “considerably higher” than those predicted from natural gas.

This is because of the more serious consequences predicted by the Warwick model for the higher concentration hydrogen explosions.

Mitigation Measures

Only one mitigation measure that might be adopted is then considered, but it makes quite a difference.

Excess flow valves – they might substantially reduce the expected number of injuries so as to be more in line with those associated with natural gas, by reducing the frequency of large and very large leaks, which would lead to the worst-case explosions. There is, however, a caveat:

[F]urther work may be needed to determine whether there is a requirement for regular long-term maintenance strategies in order to ensure these valves are performing as expected.

Small details

Unfortunately, even very small hydrogen ignitions can be disproportionately noisy, this may need to be addressed in consumer literature at an appropriate time.

Hydrogen meters should be installed outside the property for safety reasons (many leaks are apparently associated with meters).

Ventilation – very important.

Competence and training:

Existing competent Gas Safe engineers must be upskilled for facilitation of the community trial, including installation, testing and commissioning, having undertaken an appropriate training course (and subsequent assessment) for working with hydrogen gas.


A key assumption of this assessment is that hydrogen would not cause accelerated material degradation compared to natural gas in a domestic setting. And, therefore, there is no change in the likelihood of an initiating leak between the two gases. This is considered a reasonable assumption based on theory. However, there is limited published evidence regarding the use of hydrogen in low pressure networks to reference.


Headlines in newspapers such as the Telegraph, Daily Mail and the Mirror, to the effect that hydrogen boilers could cause four times as many explosions as would be the case with natural gas are justified only in terms of the effect of widespread installation of hydrogen boilers without the mitigation measures urged in the report. The clickbait picture associated with this article isn’t really justified, but at least I’m learning about clickbait from the BBC and the Guardian. And if I can’t trust those headlines, why should I trust the headlines associated with climate change?

Nevertheless, there are several caveats; also some irritating details (I for one don’t fancy a “disproportionately noisy” system, even if it is relatively safe); and potentially significant costs associated with the process. Where is the hydrogen to come from? As I understand it, it is going to be produced by electrolysis, so energy has to be used to generate a different energy source. I’m not sure that’s such a great idea.

And finally, what is the by-product of burning hydrogen? Water vapour. Isn’t that a greenhouse gas?

Well, the next stage is a Government trial of hydrogen gas. More taxpayers’ money will be spent in search of a magic solution to a problem that the UK on its own can’t begin to solve. All this despite the fact that we have an existing infrastructure and an efficient and relatively cheap source of heating our homes already. Natural gas, even after recent wholesale price rises, is still only around 20% of the cost to consumers of electricity, and electricity costs are only going to rise as inefficient, expensive and unreliable renewables become an increasing part of the mix.


i https://cliscep.files.wordpress.com/2021/08/3b050-conclusionsincqra.pdf


  1. “How hydrogen could help us to reach net zero”


    “One of the big areas that must be considered in introducing hydrogen to the gas mix is the impact to calorific value (CV). The CV drops when hydrogen is blended in, which means that more gas must be used to get the same amount of energy at the point of use. We have therefore trialled different blends containing different levels of hydrogen to optimise the output without incurring excessive cost, with 20% hydrogen currently coming out as the most favourable option from a lab perspective.”

    So is methane (natural gas) to be replaced 100% by hydrogen or only 20%? If only 20%, what’s the point?


  2. I think a key problem with hydrogen is that we intend to replace a perfectly good system – natural gas boilers – with a system that will be more dangerous, more expensive, and will cause all sorts of upheaval re: digging up existing pipes. In other words the new system has a large heap of disadvantages, and its only advantage is that there are no carbon atoms in the gas.

    If on the other hand the new system was in some way better, then I could see perhaps justifying some of the downsides. When every house had a coal fire, plumbing in gas was clearly an enormous improvement of people’s lives, even if there were attendant risks.

    The release of water vapour is not a problem however, because of rain! If substantial amounts of CO2 snowed on Antarctica then there would probably be no issue with CO2 either (as far as I know this does not happen, even when the temperature drops below the freezing point of CO2 – perhaps the air pressure is too low at the height this could potentially happen).


  3. “Hydrogen
    An Elemental Shift in How We Use Energy”


    “~95% of the hydrogen produced in the world today is derived from fossil fuels. So while hydrogen itself is a clean alternative, the fact that most of it comes from fossil fuels makes using this hydrogen counterproductive.


    An increasing amount of hydrogen is being generated from clean source (e.g. through water electrolysis using renewable or low-carbon electricity)”

    I can’t help thinking common sense has gone out of the window somewhere along the road.

    Liked by 1 person

  4. Here is what an ordinary (coal) gas explosion did at Ronan Points in London in 1968.
    However, hydrogen is much more explosive than coal and/or natural gas. Therefore, will we need to upgrade all of our high-rise buildings to be resistant to hydrogen explosions?

    Photo by Derek Voller, CC BY-SA 2.0

    [Edited to make image appear and give credit — passing admin]

    Liked by 1 person

  5. Angusmac, good question. I thought the report had been sensible by assessing the challenge of conversion in respect of a two storey, masonry-built, terraced house with a basement and a loft conversion. Maybe, however, they were avoiding the difficult question of what to do with high-rise buildings? It ain’t going to be easy, that’s for sure.


  6. I find it hard to imagine water vapor from burning hydrogen or any other industrial process having any significant greenhouse gas effect. I’d expect it to just get incorporated into the various hydrological equilibriums, but I suppose I could be missing something.

    Liked by 1 person

  7. “Climate: WWF warns UK spending is lagging behind targets”


    This is the usual propaganda from WWF and Harrabin, but right at the end of the article we get this:

    “Hydrogen warning
    One of the government’s new policy initiatives is to promote hydrogen as a power source. A hydrogen strategy is due soon.

    Lobby groups are pressing for widespread hydrogen use in home heating.

    But a report from Cornell and Stanford Universities warns that using hydrogen could increase emissions overall unless it’s made by electrolysis from surplus wind power.

    That’s because the most common current method of getting hydrogen is to split it from natural gas, which produces high carbon emissions.”

    The report in question can supposedly be found here (the link takes you to a website, not to the article, which you then have to search for, so far as I can see):



  8. More on that story in the Guardian:

    “UK plan to replace fossil gas with blue hydrogen ‘may backfire’
    Academics warn ‘fugitive’ emissions from producing hydrogen could be 20% worse for climate than using gas”


    “The government’s plan to replace fossil gas with “blue” hydrogen to help meet its climate targets could backfire after US academics found that it may lead to more emissions than using gas.

    In some cases blue hydrogen, which is made from fossil gas, could be up to 20% worse for the climate than using gas in homes and heavy industry owing to the emissions that escape when gas is extracted from the ground and split to produce hydrogen.

    The process leaves a byproduct of carbon dioxide and methane, which fossil fuel companies plan to trap using carbon capture technology. However, even the most advanced schemes cannot capture all the emissions, leaving some to enter the atmosphere and contribute to global heating.

    Professors from Cornell and Stanford universities calculated that these “fugitive” emissions from producing hydrogen could eclipse those associated with extracting and burning gas when multiplied by the amount of gas required to make an equivalent amount of energy from hydrogen.

    Robert Howarth, a Cornell University professor and co-author of the study, said the research was the first to be published in a peer-reviewed journal to lay bare the “significant lifecycle emissions intensity of blue hydrogen”.

    The paper, which will be published in Energy Science and Engineering, warned that blue hydrogen may be “a distraction” or “something that may delay needed action to truly decarbonise the global energy economy”….”.


  9. Meanwhile, on the other side of the pond:

    “Biden-backed ‘blue’ hydrogen may pollute more than coal, study finds
    Infrastructure bill includes $8bn to develop ‘clean hydrogen’ but study finds large emissions from production of ‘blue’ hydrogen”


    “The large infrastructure bill passed by the US Senate and hailed by Joe Biden as a key tool to tackle the climate crisis includes billions of dollars to support a supposedly clean fuel that is potentially even more polluting than coal, new research has found.

    The $1tn infrastructure package, which passed with bipartisan support on Tuesday, includes $8bn to develop “clean hydrogen” via the creation of four new regional hubs. The White House has said the bill advances Biden’s climate agenda and proponents of hydrogen have touted it as a low-emissions alternative to fuel shipping, trucking, aviation and even home heating.

    But a new study has found surprisingly large emissions from the production of so-called “blue” hydrogen, a variant being enthusiastically pushed by the fossil fuel industry and probably falling under the definition of clean hydrogen in the Senate bill.

    Blue hydrogen involves splitting gas into hydrogen and carbon dioxide and then capturing and storing the CO2 to ensure it doesn’t heat the planet. But this process involves the incidental release of methane, a potent greenhouse gas, and uses a huge amount of energy to separate and then store the carbon dioxide, some of which escapes anyway.

    This means that the production of this hydrogen actually creates 20% more greenhouse gases than coal, commonly regarded the most polluting fossil fuel, when being burned for heat, and 60% more than burning diesel, according to the new paper, published in the Energy Science & Engineering journal.

    “It’s pretty striking, I was surprised at the results,” said Robert Howarth, a scientist at Cornell University who authored the paper alongside Mark Jacobson, a Stanford University researcher. “Blue hydrogen is a nice marketing term that the oil and gas industry is keen to push but it’s far from carbon free. I don’t think we should be spending our funds this way, on these sort of false solutions.”

    The Hydrogen Council, a group that includes the oil companies BP, Total and Shell among its members, has said that hydrogen has a “key role to play in the global energy transition” by replacing more polluting fuels, predicting it will account for 18% of total energy demand by 2050.

    Dozens of gas companies in the US have started producing hydrogen or testing its viability in existing gas pipelines, which some climate campaigners have said is a step towards entrenching fossil fuel infrastructure at a time when the world, as outlined by Monday’s Intergovernmental Panel on Climate Change (IPCC) report, needs to rapidly move to net-zero emissions.”


  10. As so often with these schemes, it’s not as easy as it sounds.
    Blending low levels of hydrogen into the natural gas grid should not cause major problems for domestic appliances, aiui (although burners may need regular replacement). However it would cause serious difficulties for gas turbine power plants where the combustion conditions are under very tight tolerances. An HSE report concluded that the hydrogen would have to be removed pre-combustion – assuming that could be done (absorption or membranes maybe?), what happens to the hydrogen then?
    Also the level of blending is unlikely to be uniform across the country and will vary over time (assuming the source is electrolysis powered by “excess” wind generation). That has implications for the maintenance of the calorific value and, maybe, for boiler controls.

    Wrt that article/study decrying blue hydrogen, iirc Howarth, one of the authors, has form as an anti-fracker. Whenever someone bangs the methane drum I wish they could be asked how methane can have much effect outside lab experiments because its absorption spectra are swamped by water vapour which is present at 20,000 times the concentration.

    Speaking of water vapour, burning hydrogen will produce more of it than methane so homes will need better ventilation.


  11. Mike Hig, welcome, and thanks for the comment.

    I’ve been lurking at BH and observed the hydrogen discussion there, but I’m a bit busy here these days. 🙂


  12. Mark/Mike: Prof Jacobson has also been frequently on the sceptics’ radar. His most famous achievement is raising science to a new gold standard by suing someone who disagreed with him. After that hot flush he pulled the suit but was ordered to pay costs for his trouble:

    The paper in question showed that the US could live without hydrocarbons. The below quote was from the National Review in earlier WUWT coverage:

    Rather than accept any of the criticisms Clack and his nearly two dozen co-authors made, Jacobson responded with tirades on Twitter, EcoWatch, and elsewhere. He claimed that his work doesn’t contain a single error, that all of his critics are whores for hydrocarbons, and that, well, dammit, he’s right. Never mind that Jacobson overstated the amount of available hydropower in the U.S. by roughly a factor of ten and claimed that in just three decades or so, we won’t need any gasoline, diesel, or jet fuel because we will all be flying to Vegas in hydrogen-powered 737s.

    One would suspect that Jacobson would be likely to favour electrolysis over steam reforming.


  13. Politico is repeating the story, it seems:

    “EU’s clean hydrogen plan raises dirty doubts
    Methane leaks from non-renewable hydrogen could pollute more than coal and natural gas.”


    “The EU’s hopes of powering its green energy transformation with clean-burning hydrogen could potentially speed up global warming instead, scientists warn.

    A study published Thursday shows that making hydrogen out of natural gas — even when capturing some of the escaping CO2 emissions to make what’s known as “blue hydrogen” — is more polluting than simply burning natural gas directly.

    “The use of blue hydrogen appears difficult to justify on climate grounds,” the study said.

    That’s a problem for the EU. Its Hydrogen Strategy foresees ramping up production of blue hydrogen over the next decade to displace natural gas and also to use in hard-to-electrify sectors like heavy transport and steel and cement production. It’s also banking on cleaner but more expensive green hydrogen, made from water and renewable electricity, eventually becoming available in larger quantities.

    The vast majority of hydrogen produced in the EU is so-called grey hydrogen, made by splitting natural gas into hydrogen and carbon dioxide and allowing the CO2 to escape into the atmosphere. It’s relatively cheap, but has a massive carbon footprint.

    Blue hydrogen is a bit cleaner, but the process requires a great deal of energy, and that’s supplied by burning natural gas, according to Robert Horwath, professor of ecology and environmental biology at Cornell University and co-author of the study published in Energy Science & Engineering.

    Even more energy has to be used to capture the CO2 and “that electricity’s also coming from burning more natural gas without capturing the emissions,” he said….”.


  14. “Oil firms made ‘false claims’ on blue hydrogen costs, says ex-lobby boss
    Chris Jackson believes companies promoted ‘unsustainable’ fossil gas projects to access billions in taxpayer subsidies”


    “Oil companies have used false claims over the cost of producing fossil fuel hydrogen to win over the Treasury and access billions in taxpayer subsidies, according to the outgoing hydrogen lobby boss.

    Chris Jackson quit as the chair of a leading hydrogen industry association earlier this week ahead of a government strategy paper featuring support for “blue hydrogen”, which is derived from fossil gas and produces carbon emissions.

    He told the Guardian he could no longer lead an industry association that includes oil companies backing blue hydrogen projects, because the schemes are “not sustainable” and “make no sense at all”.”

    Sound familiar?

    “The UK’s future blue hydrogen projects include plans for BP to develop a hydrogen plant in Teesside, and Norwegian state oil company Equinor and SSE to build the world’s biggest hydrogen production plant with carbon capture and storage technology near Hull.”

    That would be SSE that receives subsidies to build wind turbines all over Scotland?


  15. And Equinor, remember, is the co-owner of Dudgeon, and is familiar with the right end of the money hose. BP is investing in offshore wind. The aim of these companies is to become renewables companies because they believe that our gov’t and others will either ban oil or tax it to death, but that the flow of money for renewables will never be interrupted.

    The bottom line is that however the hydrogen is made, it will have to be subsidised heavily. (Alternatively, it might be possible to tax natural gas to death or simply ban it, but first the boiler switch would have to be made.)

    Hydrogen, being worse in every way than natural gas, is never going to displace it without a large helping hand.


  16. https://www.rechargenews.com/energy-transition/uk-backs-hydrogen-cfds-to-repeat-offshore-wind-success-story/2-1-1052884

    “UK backs hydrogen CfDs to repeat offshore wind success story”

    The government is proposing using a replica of the CfD scheme that has helped build-out capacity of offshore wind in the UK to more than 10GW while also lowering its cost over the past decade by offering guaranteed ‘strike prices’ for power produced.

    The government said the publication of the document, three months ahead of the UN’s COP26 climate summit in Glasgow, sent out a “strong signal globally” that the UK is to committed to building a thriving hydrogen economy that could deliver hundreds of thousands of green jobs.

    Happened on this while looking for something else. Presumably new green farm machinery could deliver hundreds of thousands of green jobs too. (The return of oversized horses.) The obvious point is that the number of jobs only goes up if a more efficient process is displaced, via gov’t mandate, by a less efficient one.

    The success story referred to is the success of slyly sucking money out of the pockets of people who can’t afford it into the pockets of people who are already rolling in it and with whom in many cases we have very little in common w.r.t. freedom, democracy, old fashioned things like that.

    Liked by 2 people

  17. “Carbon from UK’s blue hydrogen bid still to equal 1m petrol cars
    Government’s plan to use ‘blue’ fossil-fuel hydrogen alongside green version raises concern, say campaigners”


    “Opting for hydrogen that is made using fossil fuels rather than renewable electricity could create up to 8m tonnes of carbon emissions every year by 2050, according to an analysis of government data.

    The figures show that the use of fossil-fuel hydrogen, or “blue hydrogen”, would create the same carbon emissions each year that more than a million petrol cars would produce, compared with using zero-carbon “green hydrogen”.

    Ministers plan to use both blue and green hydrogen to replace fossil gas in factories, refineries and heating, but new figures show that an over-reliance on blue hydrogen would still lead to millions of tonnes of carbon emissions entering the atmosphere every year.

    Blue hydrogen is extracted from fossil gas in a process that requires carbon capture technology to trap emissions – but this method still fails to capture between 5% and 15% of the CO2. Carbon emissions are also released when the fossil gas is extracted from oil and gas fields.

    Using blue hydrogen exclusively to replace fossil gas would result in between 6m and 8m tonnes of carbon dioxide emissions every year from the late 2020s, or the equivalent of running an average of 1.5m more fossil-fuel cars on the road every year by 2050.”


  18. “Hydrogen: UK government sees future in low-carbon fuel – but what’s the reality?”


    “…Then there are influential groups lobbying parliament on behalf of hydrogen, such as the Hydrogen Taskforce, which represents members with a vested interest in the fuel who are set to receive a significant amount of business from this strategy. But is what is good for business good for UK consumers and taxpayers?

    The UK government has failed to provide comparative evidence that hydrogen is a preferred net-zero route in many applications. Only by comparing the paths to net zero in a way that considers the complete life cycle of hydrogen fuel, quantifying the impacts on people, profit and the environment can the case for hydrogen be made accurately. That evidence is lacking in this strategy.”


  19. In Pandora’s Box, the name Lord Callanan cropped up. Here he is again:

    “Hydrogen boiler revolution ‘pretty much impossible’, says minister
    Lord Martin Callanan cast doubt on the feasibility of production demands and overall cost”


    “Using hydrogen to replace natural gas as a green alternative in boilers is “pretty much impossible”, a minister has admitted, despite the Government planning major trials over the coming decade….

    …Describing himself as a “little bit of a hydrogen sceptic”, Lord Callanan said: “If I’m being honest the idea that we could produce enough hydrogen at reasonable cost to displace mains gas is pretty much impossible.

    “Technology might get us there, there might be some scientific breakthrough. But it’s more likely that it will end up being used by trains and HGVs, for some industrial processes, rather than for home heating.
    “But the official policy is we will see how the market develops and take a view in the mid-part of this decade as to whether it will play a significant role in the home.”…

    ,,,Lord Callanan acknowledged that moving to green heating in homes is “one of the biggest political challenges that we are faced with as a government.”

    “It doesn’t get that much publicity, but it’s something that will cost us an enormous amount of money over the next 15 to 20 years.”

    Lord Callanan said plans to raise the cost of gas would be “nigh on impossible politically” amid the current energy price crunch.

    But he said it would be necessary to rebalance social and green levies, which are currently around 20 per cent of electricity bills and mean running a heat pump is more expensive than running a gas boiler.

    “To persuade people to make the change, we have to provide them with the right incentives. But it’s a difficult policy challenge. Thankfully one for the Treasury and not me,” he said.

    The Government is expected to announce a consultation on rebalancing the levies, with possible options being to move them onto gas or into general taxation.”


  20. Cross-pasting a comment on NALOPKT:
    From a report by Jacobs ( Hydrogen supply chain eveidence base; Nov 2018) on the various aspects of adopting hydrogen:

    “Efficiency:The expectation is that H 2 boilers can achieve high efficiencies, similar to those of current natural gas boilers. This would only be confirmed during the required research and development phase of commercialisation.

    Higher burning temperature can lead to NOx formation – performance may be influenced by the NOx specification (low NOx requirements could push down efficiency and may require an exhaust catalyst).

    Lifetime and maintenance: H 2 boilers are expected to achieve 10 15 year target lifetimes (i.e. similar to current natural gas boilers)
    There may be some additional service requirements, hence O&M costs are expected to be higher. Catalytic components (if required) would need to be replaced within 15 year lifetime
    Regular servicing of the appliance may need to be mandatory if components such as exhaust catalysts are needed to ensure performance of the unit is maintained.”

    So, without mitigation via exhaust catalysts, hydrogen boilers will add to NOx pollution. Fitting catalysts will increase costs and maintenance requirements, and efficiency will be lower.
    The report also includes some fairly hair-raising numbers on costs.
    It really is not a happy story.


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