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Hydrogen Boilers Greater Risk Than Gas

August 5, 2021

By Paul Homewood


h/t Ian Magness


Hydrogen more explosive than gas? Who would have thought!


From the Telegraph:





When the Business Dept rubbishes the report that it commissioned, you know they have big problems.

  1. grammarschoolman permalink
    August 5, 2021 10:34 am

    There’s an episode of ‘Yes, Minister’ exactly like this – even down to the word ‘cherry-picked’.

  2. rex permalink
    August 5, 2021 10:39 am

    Dear Paul, and other respondents, thanks for your work. I can’t follow the science of everything, but I can sense when things are being exaggerated, and “bandwagons” jumped on. If you can check out the climate change reporting requirements being imposed on Uk Pension Schemes.

    • Ian Wilson permalink
      August 5, 2021 3:41 pm

      Rex, you have touched on a real scandal, that providers such as Nest, Aviva and L & G are all virtue-signalling over climate and neglecting their duty of providing the best value pensions to those entrusting their savings to them.
      Paul ran a post some months ago highlighting the infantile posturing of Nest 9 million auto-enrolment contributors have put their faith in this outfit and will doubtless find out too late they have a rotten pension deal. I drew this to the attention of the Pensions Regulator who suggested I contact Nest – isn’t that the job of the Pensions Regulator? This deplorable quango just doesn’t seem to care .

  3. Andrew Chantrill permalink
    August 5, 2021 10:46 am

    Is hydrogen embrittlement a potential issue too?

    • Ray Sanders permalink
      August 5, 2021 4:15 pm

      In answer to your question, a very definite yes. Elemental hydrogen as an energy carrier has so many problematic issues it is beyond a joke. But none of that matters to those greenies advocating it simply because they would not understand any of the problems. I have posted about this below, for example so many advocates come up with idiot lines like “burning hydrogen only produces water” which is so scientifically illiterate it indicates the intellectual level of those proposing it.

    • Joe Public permalink
      August 5, 2021 7:34 pm

      National Grid’s Gas Operational Forum suggests adding a low concentration of oxygen can mitigate most of the effects (see pages 43-45):

      “Oxygen addition

      Oxygen has been repeatedly shown to inhibit crack growth rate and restore fracture toughness

      It is expected that concentrations as low as 500ppm (0.05%) would be suitable for most NTS applications”

      • dave permalink
        August 7, 2021 8:25 am

        That effect of oxygen only occurs in high pressure environments. I believe it kicks in at a partial pressure of oxygen of 40,000 Pascals.

        Useful for the central pipes of the Grid, but not for protecting domestic supply piping.


  4. August 5, 2021 10:48 am

    Hydrogen is obviously more risky than gas both in the home and to store and transmit.

    There is absolutely no benefit to be had from this typically harebrained climate change related piece of utter folly like this proposal and great risks emerge.
    The dept should be warned about costly litigation and odium from disasters:votes are at risk!

  5. Jack Broughton permalink
    August 5, 2021 10:50 am

    Gas explosions are most commonly in the void where the pipework runs, often under houses. These voids can be poorly ventilated so more prone to explosion.

    A problem that none of the advocates mention is that of hydrogen rising rapidly through the atmosphere and depleting the ozone layer very efficiently. Methane cannot get to the ozone layer and oxidises rapidly in the atmosphere.

    • Robert Christopher permalink
      August 5, 2021 12:29 pm

      The problem in houses is that, while doorways reach the floor, they don’t usually reach the ceiling, and neither do many windows.
      This means that any Hydrogen that escapes indoors can rise and get trapped above our heads, unlike Methane that has a molecular weight around the ‘effective molecular weight’ of air.

  6. GeoffB permalink
    August 5, 2021 11:04 am

    Although the old town gas or coal gas was 55% hydrogen, it was distributed at a low pressure, I believe 21 inches watergauge, which is 0.76 psi regulated by the big gasometers that went up and down, they only had a water seal at the base. Gas supply pipes now are at much higher pressures and any leaks will be worse with hydrogen. Here in the north east gas pipes are being renewed and the leaflet that explains why, mentions “making hydrogen ready”. So not only do we have to replace the electricity distribution wiring, but the gas one as well!!!!

    • tomo permalink
      August 5, 2021 11:29 am

      iirc Holland has gas plumbing issues consequent from different gases?

    • Ray Sanders permalink
      August 5, 2021 4:18 pm

      When I grew up in Hull the town gas was so bloody awful it was only used for cooking as it was less fuss than a coal fired range. Some people also used it for a gas poker to light the coal fire!

    • Joe Public permalink
      August 5, 2021 7:41 pm

      Hi Geoff:

      “Although the old town gas or coal gas was 55% hydrogen, it was distributed at a low pressure, I believe 21 inches watergauge”

      For most consumers, it was distributed via low-pressure mains at 8.4″w.g., which is 21mbar. The same as for ‘normal’ (i.e.low pressure) current natural gas distribution.

  7. Ian Wilson permalink
    August 5, 2021 11:19 am

    Indeed, and is it a good idea to propel cars with hydrogen? In Norway a hydrogen filling station exploded and cars themselves are akin to mobile bombs. Yes, I know petrol is explosive too, but diesel much less so. Do we really want to take this retrograde step in safety?

  8. Andrew Mark Harding permalink
    August 5, 2021 11:19 am

    The Hindenburg disaster springs to mind!.

    The problem with Hydrogen, which can never be overcome, is the size of the Hydrogen molecule, which is much, much smaller than organic gases, it is also highly reactive, and colourless and odourless, so leaks will not be detected unless an additive is used, which would also be a pollutant

    If ever there was a recipe for disaster, this is it!

    • Joe Public permalink
      August 5, 2021 1:11 pm

      Re the Hindenberg

      “The fire that destroyed the Hindenburg in 1937 gave hydrogen a misleading reputation. Hydrogen was used to keep the airship buoyant and was initially blamed for the disaster. An investigation by Addison Bain in the 1990s provided evidence that the airship’s fabric envelope was coated with reactive chemicals, similar to solid rocket fuel, and was easily ignitable by an electrical discharge. The Zeppelin Company, builder of the Hindenburg, has since confirmed that the flammable, doped outer cover is to be blamed for the fire.”

      Click to access h2_safety_fsheet.pdf

      • August 5, 2021 2:27 pm

        Do they claim the hydrogen remained unburnt?

      • Andrew Mark Harding permalink
        August 5, 2021 3:01 pm

        I stand partially corrected! However I still think hydrogen is too dangerous to use in a domestic setting., this article below confirms this

        Natural gas is about 8.5 times as dense as hydrogen, and dense gases are easier (more energy efficient) to move than less dense ones. Hydrogen partially makes up for that fact by being more energy dense per unit mass — about 3 times as much as natural gas. Cleantechnica Webpage

    • JBW permalink
      August 5, 2021 1:11 pm

      I seem to recall that you cannot add an additive to Hydrogen (to make it smell) as the smelly molecule is much heavier and does not mix well.

  9. Eddy Barrows permalink
    August 5, 2021 11:25 am

    There may indeed be a place for hydrogen in a sensibly considered long term solution to our energy needs and hydrogen fuel celled cars and possibly a similar technology in some larger transport areas are undoubtedly a better option if inherent problems can be overcome.
    As is so often the case our government started from the wrong end of the problem by testing hydrogen as a alternative to natural gas instead of first investigating feasible methods of creating the vast amount of this gas needed to replace the existing system.
    instead of a crazy and illogical rush to throw away our current energy supplies in the name of an unproven nonsense called climate change Boris should realise that as we have been threatened by this bogeyman for at least 40 years with predictions that have always failed to materialise it might perhaps be wiser to calm down, accept that there is no imminent danger, realise that whatever occurs solar and wind are the least sensible solutions and that we still have immense supplies of fossil fuels and then instead of embarking on a path of economic suicide sensibly evaluate a rational way forward.

    • August 5, 2021 11:30 am

      Total sense, except that climate has always been changeable, even from before manmade gases including CO2 were started.
      AGW is the (near-)nonsense, unlike solar and cloud influences, to name only two key variables .

    • tomo permalink
      August 5, 2021 11:40 am


      that “crazy rush” is creaking under the pressure of panaceas to the point where the proponents will not show anybody their sums…

      Do something, anything – or we’re all going to die ‘owwibbly – it’s an >emergency< – dontcha know.

      I’m fed up with being advised to “discuss reasonably” with these people when for the most part they’re irrational and woefully ill informed. I’ve put some reasonable comments in US owned UK local newspaper web sites and been piled in on by Greenies demanding that I be banned… Water off a duck’s back / confirmation that I’m over the target – but these people are unhinged and will not relent if they get hold of any power.

  10. MikeHig permalink
    August 5, 2021 11:26 am

    “hydrogen….and has never been used in a gas grid supply to homes”

    While I agree with the overall theme of the article, that comment betrays glaring ignorance and/or lack of research by the author. Many on here are probably old enough to remember Town Gas, piped into millions of homes from gas works dotted all round the country. That gas was 50 – 60% hydrogen…..

    Back in 2015 an outfit called KIWA did a study for DECC on hydrogen risks in the home. They concluded that the risk is no greater than with natural – no surprise there, given the politics. That conclusion was qualified by the need for good ventilation between floors, into the roof space and thus out to atmosphere.
    Interestingly their tests led them to conclude that a hydrogen-powered car needs a garage with a profiled roof with a highpoint vented to outside together with a hydrogen detector linked to an isolator for al wires into the garage, not just the live.
    The full report can be downloaded here:
    I was rather amused that the researchers set themselves up in a shelter 200m from the house despite using hydrogen-secure instrumentation and the house have no ignition source!

    • tomo permalink
      August 5, 2021 11:48 am


      I’m on some marketing lists for ATEX / Ex related equipment and there is some anticipation evident there that new boom times (no pun) are just around the corner wrt to H₂

  11. Cheshire Red permalink
    August 5, 2021 11:26 am

    Whether on grounds of cost, installation capacity, efficiency or safety it’s clear as day the Net Zero gas boiler ban was rushed through as policy without any regard for the realities of actually delivering it.

    None of the touted alternatives are remotely fit to replace gas.

    A textbook example of imposing an ideology at all costs. Obviously it should be abandoned immediately.

  12. August 5, 2021 11:33 am

    This time, politicos are going to have to accept UTurns and, importantly, wind up the CCCommittee.

  13. Penda100 permalink
    August 5, 2021 11:45 am

    Royal Dutch Shell on Friday 2nd July launched Europe’s biggest hydrogen electrolysis plant at the Wesseling site of its Rheinland refinery after two years of construction, as it expands further into alternative energies.

    The Refhyne plant, with a 10 megawatt (MW) capacity, will produce green fuels as part of a European Union-funded consortium which is already setting its sights on a 100 MW facility at the site near Cologne.

    What proportion of Germany’s energy needs will the 100MW plant provide?

  14. William Birch permalink
    August 5, 2021 11:50 am

    The explosive limits for for methane [natural gas} are between 5% and !7%. Above 17% the gas mix is too rich in methane to ignite. However for hydrogen the flammable range is between 4 percent and 74%. A massive difference. Not long ago {on 11 June 2019} there was a massive explosion at a hydrogen filling station for cars at the Uno-X .station in Sandvika {a suburb of Oslo}. Hydrogen has an ability to find the slightest leak. I will not be looking to have pure hydrogen piped into my house.

  15. Ray Sanders permalink
    August 5, 2021 12:20 pm

    As others above have pointed out there are significant risks with hydrogen so I will add yet another equally serious one to demonstrate the lunacy of setting up literally 10s of millions of hydrogen combustion points.
    IF you burn pure hydrogen in pure oxygen you will only get water vapour (+ energy) as a product, BUT that is NOT what will be happening. Hydrogen however pure will be combusted in AIR which is of course approx 79% Nitrogen. Hydrogen has a very high flame speed and the deflagration temperature exceeds the point at which nitrogen and oxygen surrounding the flame readily combine to produce NOx. (VW emissions scandal anyone?)
    To avoid large volumes of nitrous oxides being formed (and they are very unpleasant gases unlike benign CO2) the flame has to be a highly regulated diffusion flame.
    This paper highlights the ssue
    The prospect of over 25 million poorly regulated hydrogen boilers is a recipe for disaster .

    • Andrew Chantrill permalink
      August 5, 2021 8:10 pm

      Q: Why do Ministers make these stupid policies?
      A: Because in the Cabinet only Sharma & Coffey have science degrees…

    • MikeHig permalink
      August 6, 2021 9:09 am

      Interesting point Ray.
      There are some schemes to use hydrogen in modified ICE vehicles: I think JCB have some digger prototypes. I wonder what the NOx emissions are like?
      There’s also talk of using hydrogen storage to supply generators as back-up for renewables. Joe Public’s comment below makes that sound questionable too.

      • Ray Sanders permalink
        August 6, 2021 1:20 pm

        Joe’s point is also raised in the link I gave. The real danger with gas turbines is the premixing of the gases and air prior to injection to the combustion chamber. The increased flame speed will potentially vary dependent on the level of hydrogen included with the methane. The chances for a blow back are massively increased with possibly catastrophic detonation results. If the nuclear industry were taking risks 1 millionth as dangerous as these sorts of technologies they would be instantly shut down! But hey call it “green” and everything is okay…until it isn’t and then it’s too late.

      • Joe Public permalink
        August 6, 2021 4:09 pm


        “There’s also talk of using hydrogen storage to supply generators as back-up for renewables.”

        If the reference is to STOR, those generators, like diesel generators, are likely to be ICE rather than turbines.

  16. Vernon E permalink
    August 5, 2021 12:51 pm

    This discussion is about angels and heads of pins. Yes towns gas was substantially hydrogen and distributed at low pressure but within the home there’s no discernible difference between hydrogen and methane. Generally hydrogen disperses most effectively but neither is safe or less safe in an evclosed space. The real issue is producing the hydrogen. Maybe face can be saved all round by the compromise of putting 10% hydrogen into the existing grid – I understand that can be tolerated by the combustion devices.

    • tomo permalink
      August 5, 2021 1:19 pm

      Vernon – it’ll certainly be tolerated by the goons who will be sucking up subsidies to drizzle the magic H₂ into the pipes.

      BTW – when are they going to v=cut to the chase and have rainbow Hydrogen? So far we have “Green Hydrogen”, “Blue Hydrogen” and “Pink Hydrogen” – anybody seen other colours?

      Does Hydrogen have a gender I wonder ?

      • Ray Sanders permalink
        August 5, 2021 5:20 pm

        Oh yes tomo…how about “Turquoise hydrogen?” I kid you not. Amazingly it is quite possibly the most practical option made from pyrolysis of natural gas with a residue of solid carbon.
        p.s. does it have a gender? Probably Grilled Bacon Lettuce and Tomato plus.

      • tomo permalink
        August 6, 2021 3:27 pm

        Turquoise ?

        It’s a bit heavy on the blues and greens… we need some yellows, oranges and just possibly a splash of red (for those of a socialist persuasion?)

    • August 5, 2021 2:01 pm

      Best to let(present) well alone!

  17. Joe Public permalink
    August 5, 2021 12:57 pm

    Paul, that Arup report is based upon 100% hydrogen.

    The current main consideration is for a blend of just 10% hydrogen / 90% natural gas.

    Even with 10% of hydrogen in the blend, for consumption in power generation plants that 10% needs to be removed.

    “A combustion system particularly sensitive to variations in gas composition is the lean premixed gas turbine. Gas is mixed with high pressure and temperature air and the resultant expanding flames impinge on the turbine blades. Unwanted spontaneous ignition before reaching the burner and flashback of the flame into the burner can both have potentially disastrous effects on the integrity of the machine.

    Click to access rr1047.pdf

    See also Section 5 “Hydrogen in the NTS” here, regarding de-blending for power-station use.

  18. Keith Gguan permalink
    August 5, 2021 1:51 pm

    Hydrogen raw or in a rich mix with any other flammable gases is a very different risk from methane. Enough has been said about its intrinsic flammability to raise serious concerns. There is also its known effects or iron or steel piping (embrittlement). But its most worrying tendency, if conditions are right is to transit from explosion to detonation with devastating effects. I investigated an incident in 1971 (21st October) in a shopping centre in Clarkston, East Refrewshire, Scotland for the building insurers. 21 or 22 persons died and more than 100 were injured.
    The cause was a leak of towns gas or coal gas, containing a significant proportion of hydrogen, from a fractured gas main at one end of an inaccessible basement area which was structurally divided so as to create a long space under the entire front of the centre. Gas build up was known to be happening over many hours but the source had not been found. At about 3pm ignition occurred at one end of the space and the explosion as it progressed through the openings in the concrete dividing walls transformed into detonation destroying the reinforced concrete structure at the far end where most of the fatalities occurred.
    Details of this incident are held in my previous company, Burgoynes’, offices in London.

    • Vernon E permalink
      August 5, 2021 4:13 pm

      Keith: in the circumstances you describe would it have been any differnt if the gas was methane? A gas main failure is a potential catastrophy whatever the gas is..

      • Keith Gugan permalink
        August 5, 2021 8:09 pm

        Strictly it wasn’t a gas ‘main’ but a largish branch pipe into the shopping centre, about 3 inches in diameter. It was fully brittle-fractured around the circumference.
        Methane is much less prone to transiting to detonation. It can, of course, happen if the run-up distance (effectively L/D) is great enough or there is sufficient congestion in the flow path. The only incidents which come near to detonation with methane are vapour cloud explosions and the only one of those I am aware of was where a release of cryogenic natural gas caused significant damage at Caltex, Raunheim, refinery in January 1966. The estimated LNG release was 500kg with glass breakage extensively to 400m and minor effects at 1200m.

    • Joe Public permalink
      August 5, 2021 7:35 pm

      Regarding embrittlement, my response to Andrew Chantrill, above, may be of interest.

  19. Keith Gugan permalink
    August 5, 2021 1:57 pm

    Please note my name is Keith Gugan

  20. Keith Gugan permalink
    August 5, 2021 2:06 pm

    Where’s my blog gone? As far as I can tell I was the only one contributing who had real experience of a hydrogen-rich domestic gas explosion; where 21+ people died.

    • August 5, 2021 3:40 pm

      Sorry, WordPress thought you were a new commenter, as you spelt your name wrong Keith!!

  21. Diogenese10 permalink
    August 5, 2021 3:20 pm

    I worked on air products hydrogen tankers , all tools made of brass or rubber coated , no open flames anywhere on site , hydrogen burns with a clear flame ya can’t see it , hydrogen does not smell ,( though something could be added to create a stink , hydrogen catches fire at 60 degrees Fahrenheit ( flash point ) hydrogen is a disaster waiting to happen .

    • Jack Broughton permalink
      August 5, 2021 5:44 pm

      I don’t think that the eco-doom-warrior care if a few houses explode and people die so long as no CO2 is released. However, there will be a massive outcry from them when they find that hydrogen can mop-up the ozone layer easily.

    • MikeHig permalink
      August 5, 2021 9:55 pm

      Good to see another ex-Air Products bod on here!

  22. David permalink
    August 5, 2021 6:45 pm

    Does anyone remember the old physics lab trick of filling a golden syrup tin with coal gas and a hole top and bottom, then lighting the top hole and waiting for the explosion? It proved the fact that hydrogen has a bounce speed of more than 7 miles per second so constantly mixes to a critical point.

    • Joe Public permalink
      August 5, 2021 7:28 pm

      Ovaltine tins were bigger, held more gas, so gave a louder bang! 😉

      • It doesn't add up... permalink
        August 5, 2021 8:14 pm

        I seem to remember 7lb tins being used. Big enough for a reasonable bang.

      • tomo permalink
        August 6, 2021 8:58 am

        Some louder bangs with Hydrogen

      • Joe Public permalink
        August 6, 2021 4:11 pm


        “Some louder bangs with Hydrogen”

        Not as loud as these:

      • tomo permalink
        August 6, 2021 7:10 pm


        indeed – I see that the Germans are building some pretty big Hydrogen plants with a fair bit of political posturing and ministerial ribbon cutting.

  23. Coeur de Lion permalink
    August 5, 2021 9:34 pm

    U.K. emits one per cent of global CO2. U.K. emits one per cent of global CO2. U.K. emits one per cent of global CO2. I’m not having hydrogen anywhere near my home. Nor a smart meter. Nor an electric car.. I’m sticking to my oil fired AGA and boiler, my excellent French diesel car, and cheerful log and fircone fire in the TV lounge. House is well insulated. Try and stop me.

    • August 5, 2021 9:45 pm

      The proportion of global MANMADE CO2 emitted from the UK is between
      0.04% and
      If that is not negligible, I would be surprised.

      Yet they persist with decarbonization.
      If that’s not insane, I’d be very surprised.

  24. Jack Broughton permalink
    August 6, 2021 8:19 pm

    It has been known for many years that hydrogen rises rapidly through the atmosphere to the stratosphere. It will then react rapidly with the ozone producing high altitude ice and removing the ozone layer. None of our “Climate Scientists” seem keen to address this issue …… wonder why?

  25. Peter Young permalink
    August 9, 2021 9:48 pm

    When the Suez and Panama canals burst their banks, I might believe this.

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