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How To Generate Electricity From Air!

January 11, 2021

By Paul Homewood


 British inventor discovers the Holy Grail, well according to the i, anyway!


A ‘mad-man’ from Bishop’s Stortford isn’t always taken seriously, says Peter Dearman, but now his idea is becoming reality

In 25 years of reporting on the environment, I’ve become unshakably convinced in the seriousness and urgency of tackling climate change, but also rather dismayed that our successes in reducing greenhouse gases and promising scientific breakthroughs go largely unreported.

I’ve seen super plants that improve photo-synthesis, cows that belch less methane and next-gen solar panels. But there is one individual who deserves to be as famous in green-tech as Elon Musk for how his invention could help stop global warming.

His name is Peter Dearman and he lives in a semi-detached house in Bishops Stortford. Here, in his garage, he invented a motor that runs on air.

Meeting Dearman for my new BBC Radio 4 series, 39 Ways To Save The Planet, he tells me: “It all started when I was a teenager in the 60s looking at cars and realised that petrol was going to run out, so I started looking for an alternative.”

The “fuel” for the Dearman Engine is nitrogen, the gas that makes up 80 per cent of air. If it’s compressed into a liquid, opening a valve leads it to expand rapidly – by 700 times. This can drive a piston, just like exploding petrol vapour, but nothing is burned so no CO2 is emitted. It’s not powerful enough to drive a competitive car, but can generate electricity and more besides.

“I sat on this idea for 20 to 30 years, not being able to do anything with it, because nobody is going to pay any attention to someone in a shed,” Dearman admits. “A ‘mad-man’ from Bishop’s Stortford isn’t always taken seriously”.

A motor that runs on air! WOW!!

Except of course, it does not. Or to put it more accurately, it runs on compressed air, which in turn needs energy to compress it in the first place, a fact which the report later alludes to:




In other words, it does not generate electricity, it simply stores it, and in an inefficient way too. In other words, the process wastes energy.

I have written about Highview a couple of times, when Ambrose Evans-Pritchard hyped it as the answer to all of our problems. In reality, their 250 MWh  energy storage facility is a drop in the ocean, in terms of the storage we need to cover intermittent renewable energy.


This article is written by Tom Heap, who is the Rural Affairs Correspondent for the BBC, and oft times contributor to Countryfile. One of his contributions to the latter was a flagrantly biased broadcast against fracking, which I took apart here.

Rubbish like this latest report is par for the course for him.

  1. ianprsy permalink
    January 11, 2021 12:44 pm

    The gullibility (or is it deliberately blinkeredness?) of such reporters is astounding.

    • mjr permalink
      January 11, 2021 1:50 pm

      as it is a BBC reporter it is neither gullibility or blinkeredness. it is mendacious propaganda.

  2. January 11, 2021 12:45 pm

    The desperation in the climate movement is beginning to show.
    Or so it seems.

    • Coeur de Lion permalink
      January 11, 2021 3:59 pm

      Harrabin’s alarmism and his consistent climate denial of dissent (since his 2006 illegal conspiracy) signal that he must have an agenda. I wonder what it is.

  3. January 11, 2021 12:51 pm

    What fascinates me is that the media are behaving like a drowning man clutching at anything they can even remotely connect as Gweeen energy or best of all Thaving the Pwanent.

    Real, practical and scalability do not matter in this world of lies half lies and deception. Just like the puff about electric planes…..

    We are now at a point beyond absurd

  4. GeoffB permalink
    January 11, 2021 12:52 pm

    Tom Heap is a clone of Chris Packham (good article in todays telegraph by Ian Botham criticism him). They should both be dismissed for incompetence and bias.
    On the technical side the idea is well proven to be grossly inefficient and anyone who has worked in a factory with compressed air as a motive force knows that there is a hell of a lot of water in air, which causes all sorts of problems unless you remove it by chilling the compressed air.

  5. saveenergy permalink
    January 11, 2021 1:04 pm

    The first pneumatic motor was demonstrated France? 1840s?, widely used since in – mines, gas works, oil refineries, ammunition factories, (& by the Amish, who won’t use electricity – ) …
    Very inefficient, huge losses in compression & again in use (expansion);
    You can’t fight the laws of thermodynamics.

    • A C Osborn permalink
      January 11, 2021 4:49 pm

      Spot on, there was even a revival for a car a few decades ago in France, even Peugeot/Citreon were trying one in 2015.
      There was also aa attempt in South Africa.

  6. Harry Passfield permalink
    January 11, 2021 1:08 pm

    As soon as I saw Dung Heap’s name I knew it would be a waste of my time reading on.
    But Dung Heap says: “[over 25 years] I’ve become unshakably convinced in the seriousness and urgency of tackling climate change”: I wonder if he will ever tell us what convinced him so unshakably… I bet it’s ‘weather’.

    • Gerry, England permalink
      January 11, 2021 2:18 pm

      I got as far as that bit and thought ‘it will be downhill from here’.

      • yonason permalink
        January 11, 2021 8:07 pm

        LOL – I read “Dunghill” … Dung Heap, Dung Hill, ….what’s in a name?

  7. Joe Public permalink
    January 11, 2021 1:09 pm

    “It will use excess electricity from the grid – say on a windy night with the turbines spinning – to compress air in giant tanks.”

    Except there is no “excess electricity from the grid”.

    Firstly there never is any – renewables have priority access to market, and there’s never been even a second when fossil fuels haven’t generated some of our electricity.

    Even is there was some excess, the BBC’s world-renowned Energy Analyst has already stated that excess would be used to produce Hydrogen:

    The Beeb is trying to sell (to the gullible) the same (non-existent) commodity twice!

    • It doesn't add up... permalink
      January 11, 2021 3:09 pm

      Except I have already shown that only a proportion of the surplus might be economically usable for making hydrogen. And even that is dubious, unless the efficiency of the intermittent process can be improved radically.

      Short duration storage can only make money so long as there are short term fluctuations to be smoothed out. It depends on the margin between the cost of filling and the proceeds of redelivery multiplied by the round trip frequency. Once this drops from daily the economics crater rapidly. The residual weekly fluctuation will earn at best just a seventh of the Income, and it only gets worse after that.

      • Harry Passfield permalink
        January 11, 2021 7:18 pm

        I think Paul should get you to expand on this comment in a guest post. It is very educational. Thank you.

    • Dick Goodwin. permalink
      January 12, 2021 8:43 am

      So it doesn’t look bright (excuse the pun) for a high demand non windy evening then. Apart from that all fine.

  8. jack broughton permalink
    January 11, 2021 1:25 pm

    While the so-called “Dearman Nitrogen Engine” has been looking for backers for a long time, it is worth commenting that there are two long-term Compressed Air Energy Storage (CAES) projects in the world that are large scale and reasonably successful, both are based on gas turbines providing compressed air into large caverns.

    The older CAES unit is Huntdorf in Germany (1978). Stores 580 MWh and can provide 290 MWe.
    The newer is McIntosh in the USA (1991). Stores 2640 MWh and provides 110 MWe.

    CAES is probably the only real proven alternative to pumped hydro for large scale storage and is now well proven.

    • It doesn't add up... permalink
      January 11, 2021 3:48 pm

      In the paper we find that the efficiency of the practical CAES electricity storage is 25-45% and thus has a quite low efficiency, which is close to the efficiency of the simple diabatic CAES-process. Adiabatic CAES would reach significantly higher storage efficiency about 70-80%.

      But of course a true adiabatic process is more theory than practice.

      • jack broughton permalink
        January 11, 2021 7:26 pm

        I believe that the CAES projects were aimed at pure storage, not direct generation, (where of course they would fall-short compared with CCGTs). They are capable of good efficiency values but only by using a gas fired high temperature turbine on the discharge side.

        The importance of these is that they are proven large scale energy storage projects that most countries with caverns could emulate, rather than unproven hopefuls.

        To satisfy the anti-thermodynamic eco-warriors, they could be hydrogen based of course, even more wastage!

  9. Mad Mike permalink
    January 11, 2021 1:29 pm

    OT. Anybody got a link to a historical data site for rainfall in Canterbury?

  10. Vic Hanby permalink
    January 11, 2021 1:43 pm

    Back in the 80’s I regularly offered this up as a topic for final year engineering students. It makes no sense at all unless you also store/recuperate the heat of compression as well. That’s really difficult at scale. The BBC’s ‘analysts’ are endlessly gullible. Vic.

  11. Broadlands permalink
    January 11, 2021 2:28 pm

    There have been a large number of “gimmicks” written up in the media that could save the planet. Mostly about CO2 mitigation, capture and storage. None of them could possibly be scaled up to do enough to make a difference to the climate even if they were cost-efficient.

    Richard Feynman said it best… “For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled.”

  12. Devoncamel permalink
    January 11, 2021 2:33 pm

    Perhaps Mr Heap could use his nitrogen gismo to power the barrel scraper he evidently uses.

  13. e.b.naltonnot alot permalink
    January 11, 2021 3:13 pm

    At Jack B. above.What does the ^e^ in 290MWe represent?

    • It doesn't add up... permalink
      January 11, 2021 3:54 pm

      It refers to electricity output. All generators will incur some losses relative to the energy input to drive them. So a CCGT plant might produce 1,000MWe, but consume a 1,700MW gas supply.

  14. Ed Bo permalink
    January 11, 2021 4:17 pm

    “MWe” stands for “Megawatt electric”, in this case the electric output power of the plant, after losses. You will often see “MWth” (“Megawatt thermal”) for fossil fuel plants, which is the rate of thermal power consumption (the input) of the plant, which is substantially larger than the output.

    But be careful.”MWh” stands for “Megawatt hours” which is a measure of energy, not power (energy = power x time). Most people are billed for electricity in kilowatt hours.

  15. e.b.naltonnot alot permalink
    January 11, 2021 4:29 pm

    Thanks Ed,much obliged.

  16. mjr permalink
    January 11, 2021 5:26 pm

    this links to today’s episode of Radio 4’s series “39 Ways to Save the Planet ”
    Which is presented by Tom Heap.
    The subject today is “Chilling Foods” where the idea is to replace the diesel engines fitted to reefer wagons with these compressed nitrogen Dearman engines. Includes interview with Dearman himself

    This is episode 6 – last weeks 5 (1 a day) are
    super rice (low carbon?)
    wood for good ( using wood to replace steel in skyscrapers )
    sublime seagrass – underwater meadows .(and cows wearing scuba gear?)
    educating and empowering girls ( no idea!!
    robots of the wind (something to do with windmills)

    and so on ….

  17. Gamecock permalink
    January 11, 2021 7:30 pm

    The details of stories such as this are irrelevant. The article is selling the idea that Net Zero is feasible.

    • January 11, 2021 8:19 pm

      On the contrary, the details show that it is not feasible!

      • Gamecock permalink
        January 12, 2021 11:26 am


        ‘Meet the British inventor who came up with a green way of generating electricity from air’

        How many will read the details, and how many of those will THINK?

  18. yonason permalink
    January 11, 2021 7:48 pm

    Interview that should have happened…

    How do we get N2(l)?
    …Refrigerate the air.
    With what? An N2(l) powered refrigerator?
    Nevermind. We’ll just assume we have a supply of N2(l).

    In the motor, how do you get the phase transition N2(l) => N2(g)?
    You do know that you would have to heat it? But, with what? How hot?
    What is the optimal heat, and how do you maintain a cylinder at the correct temp for the device to give top performance? You do realize that for expansion to occur you have to have a constant source of heat, otherwise you quickly cool the “engine” to the point that going from a liquid to a gas takes longer and longer with every stroke? And, at some point, probably pretty quickly, the engine will “freeze” up. How do you deal with that?

    And then there are the safety issues. Liquid N2 isn’t the safest material to be handled on the scale that would be necessary for what you envision. What sort of distribution network and safety precautions do you recommend?

    This Monty Python-esque sketch brought to you by the BBC, Bumbling British Con-men.

    • dave permalink
      January 12, 2021 9:26 am

      This is the equivalent of the old Test Card I used to stare out seventy years ago while waiting for an actual programme to start! At least, back then, the BBC was honest enough to admit it, when they had nothing worth watching! Or were they? How many times did they inflict on me “London to Brighton by Train in Two Minutes”?

      • dave permalink
        January 12, 2021 9:29 am

        “…stare out…”

        stare at

      • January 21, 2021 12:28 am

        “At least, back then, the BBC was honest enough to admit it, when they had nothing worth watching! Or were they?”


        Actually, I remember back in the mid 70’s occasionally listening to BBC World Service (I think that was it), and after 5 minutes I knew more of what was going on around the world than I would now if I listened to them for a week. I took it for granted that they would remain that way. So much for high expectations.

  19. Vernon E permalink
    January 12, 2021 11:25 am

    Dearman clearly states that his engine runs on nitrogen – it takes a hell of a lot of (electrical) energy to separate nirtrogen from air and to generate liquid nitrogen on a huge scale would require Air Separation Units not yet seen. Of course the efficiency would be much improved if the compression was driven by gas turbines but that would rather defeat the purpose wouldn’t it? There is also refernce to “tanks” to store the liquid nitrogen, or is it the compressed air mentioned in the subsequent suggestions? What pressure (air) or temperature (liquid nitrogen) are they talking about? In either case I don’t think “tanks” really represents the enormity of the requirement.

  20. January 12, 2021 12:49 pm

    Tip: Oktopus Energy suffered a backlash on June 5th when they announced they’d be funding BLM projects
    Bulb Energy announced they be doing the same.

    I made a longer post over on bBBC at 12:31pm
    but here is a crucial line
    The money doesn’t go to Marxism, but is to be used for internal projects

    “We’re introducing a brand new project: Black Science Matters,
    a series of talks to amplify the voices of black leaders in the fight against climate change.”

    (another thing is they ban advertising in orgs that don’t support BLM)

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