Hydrogen inefficiency

Hydrogen is inefficient for many tasks:

  • Driving a car powered by green hydrogen uses about 2.3 times more renewable electricity than a car with a lithium-ion battery.
  • You can store electricity by pumping water to a high dam and then re-generating electricity by releasing the water through a turbine. This “pumped hydro” storage loses 19% of the electricity.
  • Storing renewable electricity by making hydrogen and then burning it to re-generate electricity loses 74% of the electricity; optimistically this waste could be 65%. It’s far more efficient to use pumped hydro. (Fortescue plans to burn green hydrogen at Port Kembla.)
  • Storing renewable electricity by making hydrogen and re-generating electricity with a fuel cell wastes 71% of the electricity; optimistically this waste could be 44%. Again, it’s more efficient to use pumped hydro, wasting only 19%.
  • Cooking on a cooktop burning green hydrogen uses about 3.1 times more electricity than an electric induction cooktop.
  • Heating a house by burning green hydrogen uses about 6.8 times more electricity than air conditioning.
  • Hydrogen cars in Japan: About 22% of the Australian electrical energy used to make hydrogen ends up as energy of movement for a hydrogen car in Japan. This inefficiency of hydrogen may prevent the emergence of this export market.


The relevance of hydrogen inefficiencies

I’d like to believe the hype about hydrogen, but I’m concerned about this inefficiency. The low hydrogen efficiencies show that:

  • using green hydrogen involves building more wind and solar farms to generate between 2.3 and 6.8 times as much electricity. This would tie up much more land and capital, and
  • some anticipated new hydrogen markets and hydrogen production facilities are not robust and could fail because we already have more efficient and well-established alternatives.

While these efficiency calculations are a guide, planners also need to consider costs, the environmental impacts of avoided carbon emissions, and the possible environmental impacts of large-scale hydrogen.

Caveat: These figures are based on one person’s consideration of the subject and rest on calculations, assumptions, and references described below.


Worrying plans for hydrogen: New South Wales

Many governments and companies are trumpeting hydrogen as the future of energy and have plans to use hydrogen in ways that seem inefficient. For example, the “NSW Hydrogen Strategy” targets:

  • Blending hydrogen into the fossil gas network (so the above efficiency of hydrogen for home cooking and heating is pertinent),
  • Building of the Tallawarra B fossil gas/hydrogen generator (so the above efficiency of storing hydrogen and burning it to generate electricity is pertinent)
  • A hydrogen heavy vehicle fleet & refuelling network (so the above efficiency of hydrogen cars could be pertinent.)
  • Exporting hydrogen (so the above efficiency of running cars in Japan fuelled by Australian hydrogen is pertinent)

To cover hydrogen activities like these, NSW will need to build between 2.3 and 6.8 times more renewable generation.


Key roles for green hydrogen

Green hydrogen will play a vital role where electricity does not work or is not readily available in large amounts. Australia should use hydrogen where it is efficient, for:

  • energy export to places like Japan, South Korea and Germany,
  • hydrogen hubs (to avoid liquefying the hydrogen for distribution),
  • ammonia fertilisers,
  • refineries,
  • shipping,
  • off-road vehicles,
  • steelmaking,
  • the chemicals industry, and
  • long haul aviation.

Liebreich (2021) considers 35 global uses of clean hydrogen and ranks them by how likely they are to succeed. His rankings support the conclusions of this webpage:

  • Hydrogen fuel cell cars are in the in the least competitive group.
  • Blending hydrogen into the domestic gas network (cooking and heating) is so pointless he does not even rank it.
  • Hydrogen for short term storage to balance grid demand and supply is in the least competitive group.
  • Hydrogen storage to guard against major disruption is highly likely but has competitors including pumped hydro where the geography allows.

(The clean hydrogen ladder: Liebreich: 29 Aug 2021)

(Separating hype from hydrogen: The demand side: BNEF: 16 October 2020: Liebreich)


Hydrogen cars: 33% efficient

Look at the efficiency of running a “battery car” versus a “hydrogen car” when you start with renewable electricity.

Energy using stepsBattery car efficiencyHydrogen car efficiency
Distribution: Get electricity to the car94%
Charge the car battery95%
Store the electricity in the battery95%
Electrolyser: Use electricity to make hydrogen gas76%
Compress hydrogen gas, store in a high-pressure tank & distribute89%
Fuel cell: Use hydrogen to make electricity54%
Inverter: Convert direct electric current into alternating current95%95%
Motor: Use electricity to move the car95%95%
Overall Efficiency77%33%
Efficiency compared to hydrogen car2.31

(The data comes from Shahan (2021), see the hyperlink in the References section)

To power a car using green hydrogen, you transform renewable energy in the five ways shown in the table:

  • run an electrolyser using renewable electricity to made hydrogen,
  • compress the hydrogen into high-pressure tanks, distribute it, and fill the car with it,
  • run the car fuel cell to use the hydrogen and generate electricity,
  • convert the direct current into alternating current, and
  • run the electric motor to move the car.

In each of these steps, you incur a loss of energy. The energy efficiency of each step is the “the useful energy output” as a percentage of the “the input energy”.

For a hydrogen car, 33% of the renewable electrical energy used to make hydrogen becomes the car’s useful energy of motion. The rest of the energy, 67%, becomes unwanted heat, sound, and movement.

The International Energy Association says the efficiency of fuel cell electric vehicles is lower than 33%. They say 24% (IEA, 2015, Figure 6: “power to fuel”).

(You get the 33% “overall efficiency from electricity to motion” by multiplying together the efficiencies of the five steps. I explain this type of calculation in one following section.)


A battery car: 77% efficient

To run a lithium-ion battery car, you have two of the same energy transformations as the hydrogen car and three different transformations. In all, 77% of the original electrical energy becomes the car’s energy of motion.

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Conclusion: a hydrogen car is inefficient compared to a lithium-ion battery car:

  • a hydrogen car uses 2.3 times more electricity than a lithium-ion battery car. (77 divided by 33 = 2.3)
  • the electricity needed to drive a hydrogen car 33 km would drive a battery car 77 km,
  • a green hydrogen car needs 2.3 times more solar panels.
  • fuelling a green hydrogen car should cost 2.3 times more than a battery car.

This analysis suggests that you should store electrical energy in a lithium-ion battery rather than hydrogen.

This conclusion seems to be supported by a French decision. The city of Montpellier cancelled buying a fleet of hydrogen buses as electric busses will only cost one-sixth as much.

(Massive hydrogen bus plan scrapped in favour of e-buses: The Driven: 14 Jan 2022)


A simple example of an efficiency calculation

Consider an unrealistic process consisting of two steps:

  • Step 1 is to cut a 4 kg lump of butter in two, drop one half and throw it out, keeping the remaining half, 2 kg of butter. The efficiency of step 1 is the output weight divided by the input weight, 50%.
  • Step 2 is the same as step 1. You take the surviving 2 kg of butter from step1, cut it in two, drop one half and throw it out, keeping the other half, 1 kg of butter. The efficiency of step 2 is also 50%.
  • You now have 1 kg of butter, one-quarter of the original butter.

Arithmetic gets the same answer as common sense by multiplying the efficiencies:

  • The overall efficiency is 50% multiplied by 50%
  • = 50/100 multiplied by 50/100
  • = 0.50 multiplied by 0.50
  • = 0.25
  • = One quarter.

Store energy: Pumped hydro: Loss 19%

Pumped hydro generators store electrical energy by using the electricity to pump water from a low reservoir to a high reservoir. Then to generate electricity, they run the water from the high reservoir through a turbine generator and back to the low reservoir.

The Australian National University has identified about 3,000 low-cost potential pumped hydro sites within Australia. Developing about 20 of these sites alone would be adequate to support 100% renewable energy generation. Also, investors are keen to back these projects. NSW called for pumped hydro storage proposals and got an overwhelming 28 applications with a capacity of 11 Gigawatts, 5 times the 2 Gigawatts needed to cover the wind and solar projects planned up until 2030.

(NSW flooded by 11 GW of pumped hydro proposals for the state’s big flip to renewables: Renew Economy: 2 Nov 2021).

A typical round-trip energy efficiency of pumped hydro is 81%, i.e., the energy loss is 19%.

(Blakers, Stocks & Lu (2020) Australian electricity options: pumped hydro energy storage: Australian parliament house research papers: 20 July 2020.)

Australia has so many suitable locations for pumped hydro that it’s pertinent to compare storing energy using hydrogen with pumped hydro storage.

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Store energy: Burning hydrogen: Loss 74%

Fortescue plans to build a gas-fired generator at Port Kembla, fueled by imported gas at first and then by green hydrogen. The proposal is to generate renewable electricity, make green hydrogen, and burn the hydrogen to generate electricity again.

(Fortescue to burn green hydrogen in a gas generator at Port Kembla: Renew Economy: 5 October 2021)

This proposal is surprising as generating electricity by burning hydrogen is inefficient. Consider two estimates of the round trip efficiency (RTE) of transforming energy from electricity via hydrogen and a gas turbine to get electricity again.

Process IEA Efficiency Optimistic Efficiency
Electrolysis: renewable electricity to green hydrogen 73%76% (1)
Hydrogen storage96%96%
Transport & distribution97%97%
Gas generator: Burn hydrogen to get electricity38%50% (2)
Overall efficiency26%35%
Energy loss74%65%
The superiority of pumped hydro3.12.3

The IEA efficiencies are from the International Energy Agency report (IEA, 2015). Professor Blakers of the Australian National University (Blakers, 2021) sets hydrogen round trip efficiency at 25%, consistent with the IEA figures.

The “Optimistic efficiency” is based on data chosen from the upper range of estimates to consider an optimistic case for hydrogen.

  • (1) The electrolysis efficiency is 76% from Shahan (2021) not 70% from Barnard (2018),
  • (2) The gas generator efficiency is 50% which is high in the range 34% to 51% from Albatayneh (2020, p.671).

(Hyperlinks to the referenced articles, e.g., Barnard (2018), are in the reference section below)

Storing renewable electricity by making hydrogen and then burning it to re-generate electricity loses 74% of the electricity. You use energy to store energy and this storage uses 3.1 times more electricity than pumped hydro. It’s far more efficient to use pumped hydro where the waste is only 19%.

Optimistically this waste could be 65%, rather than 74%.

There are two plans to build gas generators that will eventually use green hydrogen in this way: (1) Fortescue at Port Kembla, and (2) Origin Energy’s Tallawarra B gas generator.

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Store energy: Hydrogen fuel cell: Loss 71%

Rather than burning the hydrogen in a gas-fired generator, using a fuel cell to generate electricity is more efficient. Consider two estimates of the round trip efficiency (RTE) of transforming energy from electricity via hydrogen and a fuel cell to get electricity again.

Process IEA Efficiency Optimistic Efficiency
Electrolysis: renewable electricity to green hydrogen 73%76% (1)
Hydrogen compress & store92%92%
Fuel Cell43%80% (2)
Overall efficiency29%56%
Energy loss71%44%
The superiority of pumped hydro2.81.4

The “IEA efficiency” is again from the International Energy Agency report (IEA, 2015).

The “Optimistic efficiency” is based on data chosen from the upper range of estimates to consider an optimistic case for hydrogen.

  • (1) The electrolysis efficiency is 76% from Shahan (2021) not 70% from Barnard (2018),
  • (2) The fuel cell 43% comes from Gencell (2021) which gives the specifications of three types of hydrogen fuel cells with efficiencies ranging from 30% to 80%. (See the table at the end of the article). To do reach this 80% efficiency the stationary fuel cells must utilise the heat generated by the fuel cell. Fuel cells in cars cannot use that heat and so have a far lower efficiency of 42%.

The theoretical maximum efficiency of a hydrogen fuel cell is 85% (Barnard, 2018). So, it’s only the best stationary fuel cells that get to 80% efficiency and this fuel cell efficiency alone (ignoring the efficiency of electrolysis and compressing the hydrogen) makes this round-trip efficiency lower than 81% efficiency pumped hydro.

Storing renewable electricity by making hydrogen and re-generating electricity with a fuel cell loses 71% of the electricity, using 2.8 times more electricity than pumped hydro. Again, it’s more efficient to use pumped hydro, losing only 19%.

Optimistically this waste could be 44% rather than 71%.

(Gencell (2021) Comparing fuel cell technologies: Retrieved October 2021: See Table at the end of the article)

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These calculations suggest that storing energy via pumped hydro is more energy-efficient than storing via making hydrogen, even when using assumptions favouring hydrogen. Australia should use pumped hydro rather than less efficient hydrogen storage.

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Store energy: Emerging technologies

Due to the energy inefficiency of hydrogen, hydrogen storage investment will also be vulnerable to emerging technologies. Some challengers could be:

  • The company MGA Thermal, based in Newcastle NSW, is developing Miscible Gap Alloy blocks. These blocks could store energy from intermittent renewables to power existing coal or gas generators.
  • The company 1414 Degrees, based in Adelaide, is moving towards commercial-scale heat storage using molten silicon.
  • Form Energy is developing cheap, long duration iron-air batteries.
  • Mercedes-Benz is using solid state lithium-ion batteries in its eCitaro electric buses.

Injecting green hydrogen into town gas

In South Australia, AGN adds green hydrogen into town gas, distributing a blend of 5% hydrogen and 95% methane to homes. And the gas industry is pushing for 100% hydrogen in town gas!

The following calculations indicate that this use of hydrogen is highly inefficient compared to using electricity for home cooking and heating.


Cook by burning hydrogen: 22% efficient

Compare cooking with hydrogen and an electric induction cooktop. First, work out the efficiency of using a gas cooktop burning green hydrogen.

ProcessEfficiencySource
Electrolysis: renewable electricity to green hydrogen 76%Shahan (2021)
Hydrogen storage95%Guided by Shahan (2021)
A gas burner heating water 31%Livchak et al. (2019, p 11)
Overall efficiency22%

Cook using induction: 69% efficient

Now work out the efficiency of using an induction cooktop and pumped hydroelectricity.

As it may be possible to store the blended town gas, to compare like with like, I’ve assumed that the induction cooktop uses electricity from stored energy, i.e., from a pumped hydro generator.

Process Efficiency Source
Pumped hydro 81%Blakers (2020)
Induction cooktop: electricity to heat water 85%Livchak (2019, p.11)
Overall efficiency69%

Conclusion: Burning green hydrogen from the blended town gas on a gas kitchen cooktop is inefficient: it uses 3.1 times more electricity than an induction cooktop. (69 divided by 22 = 3.1)


Heat by burning hydrogen: 54% efficient

Compare heating a house with hydrogen and an air conditioner. First, work out the efficiency of burning green hydrogen from the blended town gas.

Process Efficiency Source
Electrolysis: electricity to hydrogen 76%Shahan (2021)
Hydrogen storage95%Guided by Shahan (2021)
A flued gas heater 70 – 80%75%Brakels (2021)
Overall efficiency54%

Heat with air conditioning: 365% efficient

Now work out the efficiency of heating using an air-conditioner powered by electricity from a pumped hydro generator.

An air conditioner (heat pump) heats a house by gathering heat from the external air and releasing the heat inside the house. An air conditioner can gather 4.5 times more heat energy than the electrical energy it uses, giving an efficiency of 450%.

Process Efficiency Source
Pumped hydro 81%Blakers (2020)
Air-conditioner: 300-600%450%Heating & Cooling (2021)
Overall efficiency365%

Conclusion: Burning green hydrogen from the blended town gas to heat a house is inefficient: it uses 6.8 times more electricity than an air conditioner. (365 divided by 54 = 6.8)


Putting hydrogen into town gas pipelines

The natural gas piped around Australia is mostly methane. Compared to methane, hydrogen has far less energy per unit volume, 3.3 times less energy. So, for the pipelines to carry the same energy, the pipes would have to transport 3.3 times the volume of gas, significantly increasing the cost of pumping town gas. Also, many pipelines would need larger diameter pipes, an expensive, long-term project. Another concern is that hydrogen can attack the structure of metal or polythene pipelines.


Hydrogen car in Asia using our hydrogen: 22% efficient

Consider making green hydrogen in Australia, liquefying it, shipping it to Japan, and then using the hydrogen to run a car. To transport hydrogen, it’s liquified by cooling it to minus 253 degrees C. This liquefaction uses about 30% of hydrogen’s energy: efficiency 70%

Process Efficiency Source
Liquefaction of hydrogen 70%
Shipping uses 5% of the energy 95%Unsourced
The efficiency of a hydrogen car33%From above
Overall efficiency22%

Only about 22% of the Australian electrical energy used to make hydrogen ends up as energy of movement for a hydrogen car in Japan. This inefficiency of hydrogen may prevent the emergence of this export market.


Shipping ammonia overseas

You can transport energy by converting electricity to hydrogen and then ammonia which is easier to ship. Despite ammonia being far easier to liquify than hydrogen, the efficiency of using ammonia seems much the same as hydrogen.

The ammonia can be used in several ways with different efficiencies:

  • electricity to hydrogen to ammonia to pure hydrogen used in a fuel cell vehicle: 11% – 19%
  • electricity to hydrogen to ammonia to pure hydrogen used in a stationary fuel cell: 21.4% electricity plus 17.9%, a total of 39.3%
  • electricity to hydrogen to ammonia burned in a gas turbine: 24% – 31%
  • electricity to hydrogen to ammonia burned in an internal combustion vehicle: 15% – 21%

These are from a CSIRO paper, “Ammonia as a Renewable Energy Transportation Media.” cited in Brown (2017)

(Brown, 2017, Round-trip Efficiency of Ammonia as a Renewable Energy Transportation Media: Ammonia Energy Association”)

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The round trip efficiency of liquid ammonia is 11-19%, which is similar to the round trip efficiency of liquid hydrogen, 9-22%

(El Kadi, Smith & Torrenete-Murciano, 2020, Hydrogen and ammonia: the prefect marriage in a carbon-free society: The Chemical Engineer)

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The above alternatives do not include using ammonia in a fuel cell. Patonia (2020) states that ammonia is best as a hydrogen carrier rather than as:

  • a fuel for burning which releases nitrogen oxides, or
  • used in a fuel cell, which could limit the nitrogen oxides and give better efficiency, but has technical challenges.

(Patonia: 2020: November: Ammonia as a storage solution for future decarbonised energy systems: The Oxford Institute for energy studies.)

If you find articles countering these conclusions, please let me know so I can improve this page.


Energy for desalination

An electrolyser needs water to make hydrogen, 9 kg of pure water per kg of hydrogen.

Australia has large desalination plants in Queensland, NSW, Victoria, South Australia, and Western Australia. Also, the proposed Asian Renewable Energy Hub in the Pilbara will desalinate seawater. So, let’s consider the energy required to desalinate the water used in making hydrogen. As it turns out, the energy used in the electrolysis is so large that you can ignore the power used in desalination.

(Electrolysis uses about 48 kWh per kg of hydrogen while desalination uses about 0.004 kWh per kg of hydrogen.)

Hydrogen’s expanded role would use less water than the current coal industry, about one quarter.


Petrol engine energy loss: 73% – 89%

The “well to wheel” energy efficiency of a petrol-driven car is between 11% and 27%. (Albatyneh et al., 2020, in the abstract), so the energy loss is between 73% and 89%. We have used low-efficiency fossil fuels for a long time, but for many tasks, we now have far more efficient alternatives than both fossil fuels and hydrogen, so the hydrogen economy may not take off.

Note, the well to wheel efficiency of a car considers:

  • energy used to extract the oil from the oil well,
  • energy used to refine the oil,
  • energy used to distribute the petrol,
  • energy provided by the petrol, and
  • the useful energy supplied to the car wheels to move the car.

Hydrogen: Climate risks

Hydrogen could play an essential role in supplying energy to the world. This role would bring occasional significant hydrogen escapes and ongoing hydrogen leaks, e.g., from aging, re-purposed town gas pipes. So, we need to understand the impact of this on our atmosphere.

Over the past 25 years, atmospheric hydrogen gas has increased by 4%, and scientists do not understand what is driving this.

Scientists do know that hydrogen could damage our atmosphere. The hydroxyl radical (OH) cleanses the atmosphere of greenhouse gases like methane and toxic gases like carbon monoxide. An increase in hydrogen levels could decrease levels of hydroxyl radicals and so increase the levels of damaging gases like methane and carbon monoxide.

A further concern is that when you (1) convert the hydrogen into ammonia and then (2) either burn the ammonia or use it in a fuel cell, this can release nitrogen oxides. These oxides are bad for health, can attack ozone, and add to greenhouse heating.

The massive use of hydrogen may not be “clean”.

(Don’t rush into a hydrogen economy until we know all the risks to our climate: The Conversation: Pearman & Prather: 10 Aug 2020)


Making green hydrogen more competitive

Currently, the cost of producing green hydrogen is $5/kg, and the federal government says this cost needs to fall to $2/kg to make it competitive with fossil fuel hydrogen. To make green hydrogen competitive with fossil fuel hydrogen, you need to improve the electrolyser efficiencies and decrease the cost of solar and wind generation. (Note, a carbon price would help!)

To make green hydrogen more competitive with batteries and pumped hydro, you need to increase the efficiency of (1) electrolysers producing hydrogen from electricity, (2) storage of hydrogen, and (3) the fuel cells generating electricity from hydrogen.

We do not need new hydrogen markets to enable large-scale green hydrogen production with its cost reductions so that green hydrogen can compete with fossil fuel hydrogen. We do not need these new markets as the current global hydrogen demand is large. To meet this current global demand would use a large amount of renewable energy generation: 1.6 times the 2020 global wind and solar generation.

You could also reduce the cost of green hydrogen by paying electrolysers to slow production during periods of electricity scarcity. If we have large scale hydrogen production, then there will be a considerable ability to slow production. The electrolysers would be earning money by making electricity available to others, acting as virtual batteries. Woodside is planning to use electrolysers like this in the Perth grid, making green hydrogen. Unfortunately, they also plan to produce hydrogen from fossil fuels.


The inefficiency of hydrogen is an advantage for our industry

The inefficiency of green hydrogen/ammonia and the energy involved in exporting them give Australian industries an advantage: cheaper electricity than in countries that import hydrogen. This cost advantage could allow Australia to process more minerals in Australia, rather than simply being a quarry. We would then be exporting more renewable energy embedded in processed minerals.

If Australia manages to export electricity by cable at a low cost, then there is a chance that we will lose this advantage. It means there is a limited window of opportunity for Australian industry to expand infrastructure and establish markets before our electricity is cheaply available overseas, for example, in Singapore.


Why is so much money going into hydrogen

The above simple energy calculations suggest that hydrogen is inefficient for:

  • storing energy,
  • powering a car,
  • generating electricity,
  • heating homes, and
  • cooking on a stovetop.

Companies like BHP, Fortescue, and Macquarie have made plans to produce green hydrogen. There are plans for 35 electrolysers, many of them with an enormous capacity.

(Australia has 38GW of green hydrogen in the pipeline, but major cost falls are needed: Renew Economy: 11 June 2021)

Surely these organisations know what they are doing.

In some regions, hydrogen may be the best alternative, e.g., where pumped hydro storage is impossible or where installing electric vehicle charging is too difficult. Hydrogen does carry a huge amount of energy per unit mass, and filling hydrogen cars is quicker than charging electric vehicles.

Some authors are concerned that fossil fuel companies may be backing the hydrogen economy to (1) sell hydrogen produced from fossil fuels or (2) use their gas pipelines and sell gas.

I would like the green hydrogen economy to succeed, but I’d like to understand how it can compete given its apparent inefficiency.


Maximum electrification

Blakers (2021) says that Australia can rapidly and cheaply cut 80% of our greenhouse emissions by electrification using mature, low-cost, and reliable technology:

  • installing:
    • wind and solar farms,
    • transmission lines, and
    • pumped hydro and batteries,
  • moving to electric vehicles, and
  • electrifying heating.

This electrification would:

  • reduce our development of inefficient hydrogen infrastructure, like:
    • hydrogen refuelling stations for cars, and
    • hydrogen blending into town gas,
  • build a green electricity grid, and
  • supply cheap power to foster the expansion of Australian industries like mineral processing and green hydrogen production.

References

Albatayneh, A. et al. (2020) Comparison of the overall energy efficiency of internal combustion engine vehicles and electric vehicles, Environmental and Climate Technologies, vol 24, no 1, pp 669-680: Retrieved from Sciendo Oct 2021.

Blakers, A. Stocks, M. & Lu, B. (2020) Australian electricity options: pumped hydro energy storage, Australian Parliamentary Library 20 July 2020

Blakers (2021) Australia can achieve rapid, deep, and cheap emission cuts from the technology we have now: Renew Economy: 7 Sep 2021.

Barnard, M. (2018) What are the pros and cons of using hydrogen to generate electricity, from Forbes, 8 May 2018

Brakels, R. (2021) Air Conditioners Will Heat Your Home Cheaper Than Gas. Here’s Why. Solar Quotes, 23 August 2021

Heating & Cooling (2021) Australian Government, Dept of Industry, Science, Energy & Resources: Retrieved October 2021

IEA (2015) International Energy Agency: Hydrogen and Fuel Cells Technology Roadmap: Figure 6, Page 21

Livchak, Hedrick & Young (2019) Residential Cooktop Performance and Energy
Comparison Study, Frontier Energy report, July 2019

Shahan, Z. (2021) Chart: Why battery electric vehicles beat hydrogen-electric vehicles without breaking a sweat from CleanTechnica, 1 February 2021


An overview of Australia’s progress towards renewable energy superpower


Updated 21 Jan 2022