The “Green Hydrogen” myth. It is a delusion

Aug 17, 2021

Are you also being swamped with optimistic articles about how essential it is for Australia to be a leader in “green hydrogen”?  “Green hydrogen” is being spruiked as essential to our decarbonised economic future and as a strategic decarbonised export opportunity.

“Green hydrogen” is being distinguished from much cheaper “grey hydrogen” that we currently produce from gas (natural or fracked) by steam reforming.  We also have “blue hydrogen” – which is “grey hydrogen” with the extremely dubious promise of carbon capture.  According to Howarth and Jacobson, when fugitive emissions are considered “blue hydrogen” has 20% worse emissions than “grey hydrogen” and only “green hydrogen should be considered.

But how green is “green hydrogen” really?  Superficially it’s green, because it’s made by passing renewable electricity through water to liberate hydrogen and oxygen with no CO2 emissions.

But what if we put the same renewable power onto our electricity grids instead of making hydrogen?  This would displace coal and gas fired power – every MWh of renewable electricity put onto the grid would displace ~3MWh of fossil fuels being burned to supply grid electricity and eliminate over a tonne of CO2 emissions.  The electricity used to generate hydrogen really has the same impact as the electricity that supplies our grid – 72% fossil fuel powered.  “Green” hydrogen will only be truly green when our electricity grid is fully decarbonised.

Hydrogen is being spruiked as a “green” wonder energy source that can be used for just about anything – for vehicles, for ships and planes, for long-term electricity grid level storage, in industry to make steel, fertilisers and chemicals and in homes distributed through existing gas pipelines.  It can also be used in fuel cells to regenerate electricity or converted to ammonia which is easier and safer to transport.  Let’s put these claims under the microscope:

For vehicles:

  • 1 kWh of renewable electricity → 0.7kWh of compressed hydrogen → 0.18kWh of shaft power using ICE, or 0.38kWh using Fuel Cell Electric Vehicle

o   18% – 38% efficient (Ammonia 20%)

  • 1 kWh of renewable electricity → 0.99kWh Li ion battery Electric Vehicle → 0.9-0.95kWh of shaft power

o   90-95% efficient

A hydrogen powered conventional vehicle would use 5 times and a fuel cell electric vehicle 2.4 times the renewable energy of a battery electric vehicle.  According to Bloomberg NEF, battery electric vehicles will be the cheapest cars to produce by 2027 so why would any consumer choose a more expensive, hydrogen powered vehicle instead of a battery electric vehicle?

Decarbonising transport and eliminating petrol/diesel vehicles will take 3-5 times as long with green hydrogen/ammonia as with battery electric vehicles – the oil industry love it!

For electricity grid energy storage:

  • 1 MWh of renewable electricity → 0.7MWh of hydrogen compressed →0.42MWh of Grid Electricity

o   42% efficient

  • 1 MWh of renewable electricity → 47kg of Ammonia → 0.31MWh of electricity + 19MWh of heat (CSIRO)

o   31% efficient

  • 1 kWh of renewable electricity → Pumped Hydro Storage → 0.8kWh of grid electricity

o   80% efficient)

  • 1 kWh of renewable electricity → Li ion battery storage → 0.99kWh of grid electricity

o   99% efficient

Using hydrogen or ammonia for grid level storage wastes 2-3 times as much renewable power, delaying our transition to renewables, delaying decarbonisation of our electricity supply and prolonging our use of coal and gas fired power – the coal and gas industries love it!

To make 1 tonne of steel:

  • Traditional blastfurnace/BOS steel requires 0.82tonnes of coal + iron ore

o   emits ~3 tonnes of CO2

  • Hydrogen steel production requires: 0.6 tonnes of hydrogen + iron ore

o   Grey hydrogen requiring 4.9 tonnes of Natural Gas

  • emits ~13 tonnes of CO2

o   Blue hydrogen requiring 6 tonnes of Natural Gas

  • emits 16 tonnes of CO2

o   “Green” Hydrogen from 34.4MWh of renewable energy diverted from grid

  • superficially emits no CO2
  • causes ~38 tonnes of CO2 emission to supply the grid (2020)

“Green steel” is only superficially green – if the renewable energy used to make the hydrogen were instead put on the grid then this would prevent 38tonnes of CO2 emissions per tonne of so-called “Green” steel being produced.  On this basis, traditional coal fired steelmaking has the lowest CO2 emissions, with all hydrogen based steelmaking having at least 4 times the emissions per tonne of steel, with so-called “green” steel having over  10 times the emissions.

We are being sold the idea of transitioning from coal produced steel to decarbonised “green” hydrogen produced steel.  None of this will actually reduce emissions now compared to conventional steel production – the only winners here would be the oil and gas industries delaying decarbonisation under the guise of a transition to green steel, so they love it!

Decarbonised steel production using hydrogen WILL be valid but ONLY after our grid has substantially transitioned to decarbonised energy.

What about hydrogen and ammonia as transportable renewable energy?

  • 1 MWh of renewable electricity →

o   Transmitted by pipeline → ~0.7MWh hydrogen transmitted by pipeline

  • 70% efficient

o   0.5MWh of ammonia → 0.4MWh ammonia transmitted by pipeline

  • 40% efficient

o   Transmitted by Cable HVAC→ 0.94kWh

  • 94% efficient (HVDC 96% efficient)

By truck or ship, the losses depend on distance, but will always be considerably higher than pipeline transmission and certainly never compete with high voltage electric cable transmission.

As a medium for storage or transmission of renewable energy, hydrogen (and even worse ammonia) would waste significant proportions (26-57%) of the stored energy further delaying  decarbonisation – the gas industry loves it.

“Green” hydrogen really is the fossil fuel industries wet dream – a superficially “green” solution to all our problems that will delay the transition out of fossil fuels for our transport, our electricity grids, our industries and our exports.  With the release of IPCC AR6 revealing just how extreme the urgency to decarbonise,  substantially before 2030 and reach net zero significantly before 2050, we MUST expose this dangerous delay tactic from the fossil fuel industries that have already sponsored 3 decades of climate denial.  We must expose the delusion that hydrogen can be “green” until our grid is fully decarbonised.

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