Pursuing the hydrogen economy as a climate solution will be a big mistake

This post is by David Cebon, professor of mechanical engineering at Cambridge University.

There has been a lot of talk about hydrogen in the past year or two. Advocates for a ‘hydrogen economy’ make claims about how ‘green hydrogen’ (made by electrolysing pure water with renewable electricity) will power future energy systems. The idea is that green hydrogen will be generated at times of day when renewable electricity is cheap (ie when supply is high and demand is low). The hydrogen gas will be stored in underground salt caverns until needed and then either converted back into electricity and injected into the electricity grid or piped around the country to heat buildings and fuel lorries.

A promise to solve the big carbon problems
The promise is that, with one silver bullet, this imaginative scheme solves three big decarbonisation problems: electricity storage, heating buildings and powering heavy transport systems.

Some of these advocates recognise that generating and storing green hydrogen at the necessary scale is an immense task that will take many decades to achieve. Consequently, they propose to use ‘blue hydrogen’ as a stop gap. This is made from natural gas by a Steam Methane Reforming (SMR) process, then the resulting CO2 by-product is captured and stored in depleted oil wells (otherwise known as CCS).

Alternatively, an ‘electron economy’ uses electric heat pumps to heat buildings, battery-powered or catenary-powered electric lorries and various possible technologies with high electricity storage efficiency.

The hydrogen economy vs the electron economy
Over the past year I have researched and written technical blogs on these subjects: on powering lorries, heating buildings and electricity storage, and one bringing together the arguments. Here are my main conclusions:

  1. Energy conversion processes required by the green hydrogen economy (electrolysis, compression, storage and fuel cells) are very inefficient: wasting energy as low grade heat. A huge amount of new renewable electricity capacity would be needed to compensate for the wasted energy.
  2. The proposed green hydrogen economy is unlikely to be realisable in the UK because of sheer amount of renewable electricity required, the low Technology Readiness Level (TRL) of large scale electrolysis and the undeveloped technology for storing hydrogen in salt caverns.  An ‘electron economy’ has a significantly higher likelihood of success, in a much shorter timeframe.
  3. For heavy goods vehicles, direct electrification, via batteries and ‘electric roads’, are options with a higher TRL, lower energy consumption, lower carbon emissions and lower costs than hydrogen-powered fuel cell vehicles.
  4. Heat pumps are a much better option for heating buildings than hydrogen boilers. Heat pumps are readily available now and have much lower energy consumption, carbon emissions and fuel costs.
  5. For electricity storage, green hydrogen is unlikely to be competitive with more efficient alternatives such as cryogenic (liquid air) storage and compressed air storage.  Both offer almost equivalent storage capabilities at much lower ‘levelised cost of storage’, and higher TRL.
  6. Shifting the energy for lorries and heating buildings to blue hydrogen would result in the UK importing and burning an additional 260 TWh of natural gas per year. This would increase natural gas imports by 50 per cent and increase overall gas consumption by nearly 30 per cent.  It would be detrimental to the country’s balance of trade and energy security.
  7. The push for hydrogen is likely to delay the international decarbonisation project and undermine efforts to keep the global average temperature less than 1.5 oC or even 2.0 oC above pre-industrial levels.

So why is there suddenly so much hype about hydrogen?

A lifeline for fossil fuel companies
Peer reviewed research shows there is currently a concerted effort by an international ‘discourse coalition’, “primarily of gas industry incumbents, [who are] under threat from the decarbonisation of heating” and that “the green gas storyline is being oversold by incumbents.”  In other words, the international fossil fuel industry, which is under existential threat from electrification, is promoting hydrogen as a solution: to create confusion among politicians and the public and delay its own demise. According to Pierre-Etienne Franc, founding member and secretary of the Hydrogen Council who leads hydrogen projects at Air Liquide: “Ultimately, blue hydrogen is an easier way for an oil company to pivot to clean energy than going full-on renewable… It’s a way to avoid having stranded assets from the current fossil fuel-based system”.

Undoubtedly, the main players in the hydrogen lobby understand they cannot deliver on their promises.  They know green hydrogen is a deeply flawed concept. Consequently, they are pursuing a ‘bait and switch’ strategy in which they promise a green hydrogen future but then fall back to an interim blue hydrogen position which will consume a large amount of additional natural gas. 

They also know that blue hydrogen will take decades of development to deploy at sufficient scale, during which time they can sell much cheaper ‘grey’ hydrogen(made by the SMR process but with CO2 released into the atmosphere) instead.  They ignore the fact that grey hydrogen will make CO2 emissions considerably worse than the status quo (ie just burning natural gas).

This delay will give the fossil fuel industry a (temporary) reprieve.  They also know that they won’t be able to deliver the promised net zero future because the CCS process will always leak at least ten per cent of the CO2 into the atmosphere and the oil and gas supply chain will continue to generate fugitive methane emissions, equivalent to the carbon footprint of Europe.

The hydrogen economy will not be viable long term
It is probable that the hydrogen economy project will fail in the end. Hydrogen solutions are far too expensive to compete with electric solutions, because hydrogen processes are fundamentally inefficient and waste a lot of valuable energy.  Just as the free market has rejected hydrogen powered cars because of their excessive energy costs, so too the market will conclude that hydrogen powered lorries, hydrogen powered heating and green hydrogen electricity storage are all too expensive to compete with energy efficient electrical alternatives. 

Unfortunately, this will take years to play out. In the meantime, encouraged by the hydrogen hype, the government will continue to subsidise hydrogen projects and technology development and the hydrogen lobby will continue to obfuscate its fundamental lack of competitiveness.

The tragic consequence is that confusion and delay will threaten to derail efforts to decarbonise the nation and the world in time to prevent the worst effects of global warming.  This should be of major concern to the environmental movement.

Electrification is the route to fast decarbonisation
If the UK government is serious about decarbonisation, it should pursue a strategy of electrifying everything possible, as soon as possible. That includes all land transport and heating of buildings, with a commensurate large scale increase in sustainable electricity generation. There should also be a strong emphasis on energy efficiency throughout the economy, including insulating buildings and improving the energy efficiency of lorries. Hydrogen should only be used for the applications that cannot be electrified.  These include some industrial processes, possibly aviation and the  manufacture of ammonia, which is used for fertiliser production and is being proposed as a liquid fuel for shipping.

11 comments

  • Very useful to have the academic know-how to back arguments against continuing with “bridge” gas, as we are seeing with Nordstream2. I was particularly struck by the negative findings for HGVs, which I had thought could be H2 powered. No comments on long distance/freight trains, though.

  • How will sustainable electrification on the scale you envision be implemented?

    Will this require nuclear power since to electrify the economy at the scale you intend will increase electricity demand by at least a factor of 10.

    Similarly, heat pumps are only suitable for back ground heat and will require additional heat sources to comfortably heat homes in winter. The exception is when heat pumps are deployed in passive heat housing. This will require planning reforms so that homes are built south facing.

  • How well suited are heat pumps for UK houses that are centrally heated using micro-bore piping? Said piping being quite common in the period 1980 onwards. If HPs are implement In such houses it require the removal/replament of an existing heating system.

    Houses also need significant thermal renovation to take heat pumps (unless you are happy with a very very high elec bill). UK gov (or what passes for one) has just cancelled the not-fit-for-purpose energy renovation scheme.

    In the case of this assertion: “Green Hydrogen energy storage has not been demonstrated at any significant scale, is at the lowest TRL and is far from being implementable at grid scale.” Could this be an example of British insularity?

    Fact: Iberdrola, Spain, 100MW of PV and 20MW of electrolysers (H2 to feed a fertiliser plant) – being built now. Naturgy, Spain, 400MW of PV and 60MW of elecrolysers, being built – now & injection into gas system). The Dutch will build 500MW of electrolysers in Rotterdam (fed by off-shore wind). If Prof Cebon was honest with himself he would have to admit that the TRL for electrolysers is 9 (i.e. commercially available/ready for deployment). Remind me when/where the factory for building 1GW/year of liquid air systems will be built? (The one for electrolysers is in Sheffield btw and just about complete).

    As I read the various blogs and this article, it all seemed quite plausible and took me back to the days of Against Hot Air. Unfortunately, as the examples above show, a blend of “devil in the detail” and UK insularity may result in the UK (or Ingerland?) making some serious mistakes.

    Nearly forgot: electricity distribution networks (I used to design, build & operate them btw) even with a fully renovated housing stock you will run into a significant network constraint in a HP & elec vehicle world. Very roughly speaking, a given HV/LV sub will run out of capacity at around 30% HP/20% EV penetration. This is not Tx capacity btw – this is all to do with statutory voltages etc. All these devils in the detail eh!

    • I won’t opine on microbore per se, since it is complex issue and I am not an expert. But it relates in general to the near-term problem with heat pumps. They are very energy-efficient once installed, but also very expensive to purchase and install. Homeowners with working furnaces based on gas or heating oil will need to be strongly incentivized to make the switch.

      The solution would be to mandate heat pumps for all new construction or HVAC system replacement, then let robust / increasing carbon taxes slowly pressure people to replace fossil-fired appliances. Meanwhile, renewable methane and renewable fuel oil options should also be motivated by rising carbon taxes, so that the fired heating systems that do remain can gradually reduce their fossil footprints.

  • What about a methanol economy as George Olah proposed to capture atmospheric CO2 and use it as a range extender to electromobility, chemical feedstock, etc?

    • Methanol is an excellent medium for any situation in which a MATERIAL is needed. This includes liquid and gaseous fuels. Methanol can easily be converted to methane or to a heating-oil substitute. If it is renewable, then such materials can replace their fossil equivalents.

      But ultimately, for applications where electrical energy can be used directly, it will be more efficient. For example, home heating should eventually be converted to electricity. Methane based on renewable methanol could be a stopgap measure, but it’s not the best long-term solution. OTOH, jet aircraft are probably never going to fly based on stored electricity, and methanol can be readily converted to jet fuel, so that is a long-term use.

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  • Burgeoning developments in advanced nuclear power plants changes the prospects for green hydrogen (GH2) manufacture substantially, for the simple reason that electricity from nuclear power plants (NPPs) is of the 24/7/365, despatchable variety. The concentration, in the EU (particularly Germany) on manufacturing GH2 from marginal cost electricity generated by wind and solar power plants (WASPPs) is financial and environmental suicide for these ridiculous and ephemeral technologies.

    From June to January, UK electricity demand varies by 7 TWh. Gas backup plants with OCCs of £3 billion per year corrects for the intermittency problems but in replacing gas, is your technology of choice any better than GH2?

    To guarantee 24/7/365 reliability from WASPPs, LAES technology does carry an enormous overnight capital cost (OCC). To store 7 TWh of WASPP’s intermittent generation would require 28,000 Highview Power’s 50 MW CRYObattery plants with an OCC of £308 billion and a lifespan of 30 to 40 years – that’s £9 billion every year, forever. Add onto that the £15 billion or so annual OCC for a 100% WASPP scenario = £24 billion per year.

    Rolls-Royce are building a factory this year to start the manufacture of their 440 MW NPP, with a commercial operation date of 2029. From 2030 onwards, with a build programme between 3 and 4 years, volume production could easily decarbonise the UK’s electricity generation by 2050, at an annual cost equivalent to 1/6th of WASPP despatchable electricity, at £4.06 billion per year.

    Search for: billion-every-year-forever-ce41e7c1fdf9

    With €130 billion of investment in the EU going into a GH2 economy, there will never be a single ‘electric road’ sited anywhere on the continent. So with maybe 5 million powered vehicles shuttling between the UK and EU each year it would be anathema for trade to not have a UK hydrogen refuelling network for EU trucks or expect ‘electric roads’ to put in an appearance in EU nations.

    ITM Power have started building a PEM electrolyser giga-factory which is expected to cut electrolyser costs dramatically and in the EU and USA, improvements in the technology costs across the board for a hydrogen economy is expected to match all the market costs for fuelling and operation of diesel powered vehicles by around 2030.

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  • The Author makes many good points. An additional one is that H2 production based on “excess off-peak power” or on intermittent renewable electricity in general will only operate some of the time. This means buying expensive equipment to electrolyze and compress hydrogen, but then being able to operate it only a fraction of each day.

    (Hydropower, geothermal, and nuclear would be more effective, since they can operate 24/365)

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