Hydrogen and energy

The production and uses, and advantages and disadvantages, of hydrogen as a fuel

Electricity is very useful to power our machines, but it is also useful to have liquid or gaseous fuels that can be put in a tank and carried around in cars or planes or conveniently stored.

When we burn fossil fuels like petrol (gas to an American), diesel or the kerosene that we use in our jet planes the greenhouse gas carbon dioxide is released into the atmosphere. This has done enormous harm through climate change and ocean acidification as well as air pollution that kills millions of people world wide each year. So we must kick the fossil fuel addiction as quickly as possible.

Hydrogen is a gas that when burned (or reacted in a fuel-cell) produces more energy per kilogram than any fossil fuel, and all that is released into the atmosphere is steam. It has been considered as a replacement for fossil fuels for many years, but there have been a number of serious hurdles that had to be overcome for it to become a sustainable and practical fuel. It seems in 2018 that enough of the problems associated with hydrogen have been solved for us to begin to use it in serious quantities without harming the environment.

I have written on another page on this site about several proposals for producing hydrogen from renewable energy in South Australia.

A South Australian wind farm

Photo taken by my drone, 2016/08/14

Hydrogen production

While hydrogen is by far the most common element in the Universe it does not occur in its free form above or under the surface of the Earth in useful deposits. However it is plentiful in chemically combined form in petroleum (combined with carbon), and most importantly as far as sustainability is concerned, in water (combined with oxygen).

How do we get free, uncombined, hydrogen?

There are four main methods by which hydrogen is commercially produced. The first three involve the use of natural gas, oil or coal. The last uses the electrolysis of water. They account for 48%, 30% 18% and 4% of the world’s hydrogen production respectively at or about the time of writing: (Wikipedia). The first three methods are of no use if we are to achieve the zero carbon economy that we must have if we are to not irreparably damage the planet because they all involved burning fossil fuels and releasing carbon dioxide.

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Electrolysis, which uses electricity to break hydrogen away from oxygen in water can be powered sustainably by renewable energy without producing greenhouse gasses.

Mugga Lane solar farm, Canberra, ACT, Australia

Photo taken by my drone, 2016/11/07

What's wrong with using gas, oil or coal to produce hydrogen?

If natural gas is used to produce hydrogen, for every tonne of hydrogen 9 to 12 tonnes of carbon dioxide (CO₂) are also produced (Wikipedia). If oil is used, even more CO₂ is produced, and coal is far worse again.

Natural gas and oil contain substantial amounts of hydrogen, coal contains very little. When coal is used to produce hydrogen it serves only as a source of the energy needed to break the water molecules into free hydrogen and oxygen atoms. This results in huge amounts of CO₂ being released; for example, in a pilot plant for using brown coal to produce hydrogen to be built in Australia, 160 tonnes of coal will be used to produce three tonnes of hydrogen, along the way releasing 450 tonnes of CO₂ into the atmosphere; that is 150 tonnes of CO₂ for every tonne of hydrogen.

A process called carbon capture and storage can theoretically be used to catch the CO₂ and put it in underground reservoirs where it will stay for many years. However, this process is so expensive that it is rarely used.

Worldwide the production of hydrogen is a major industry. Chris Goodall states in Carbon Commentary that 1% of the world's greenhouse gases come from the production of hydrogen. There is every reason to believe that hydrogen production and use will increase greatly in years to come so making that production sustainable is very important.

Electrolytic production of hydrogen

Sundrop Farms – the solar power installation

Sundrop Farm is a huge greenhouse development near Port Augusta in South Australia, powered by solar including the desalination of the water required. Photo taken by my drone, 2016/03/14

French company Neoen is intending to build the Crystal Brook Energy Park (CBEP) in northern South Australia. The CBEP will include a wind farm, solar farm, big battery and an electrolytic hydrogen plant aimed at producing 20 tonnes of hydrogen per day. Garth Heron of Neoen has said:

"At CB we are aiming to be competitive with Australian based steam methane reformation economics for hydrogen production."

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I believe that most Australian steam methane reformation would use natural gas; that is, mainly methane.

There is another renewably powered electrolytic hydrogen production plant planned for Port Lincoln, also in South Australia. It has been reported that the Port Lincoln facility will produce ten tonnes of hydrogen per day.

It is worth noting that photo-voltaic solar with electrolytic hydrogen production could compete with solar thermal power with storage.

Why use renewable energy to make hydrogen?

Hydrogen can be made using coal as an energy source or from methane by steam-methane reformation, but both processes result in carbon dioxide emissions. Hydrogen can be made by electrolysis, powered by renewably generated electricity, without any carbon dioxide emissions.

As more and more renewable energy, wind, solar PV, solar thermal, wave and others are built, there will be an increasing need to store excess energy when generation is greater than demand.

At present there are times in South Australia, where an average of half of the electricity is generated by wind and solar, when wind turbines have to be turned off because there is too much power being generated.

Some excess energy can be sent elsewhere (interstate in the case of South Australia), but this is limited by the capacity of the power interconnectors, some can be stored in batteries, some in pumped hydro systems, and some can be converted to hydrogen.

What can hydrogen be used for?

Hydrogen has many uses and potential uses. Like so many other things, cost is an important factor; the lower the cost the more uses become viable.

Some uses of hydrogen:

It can be injected into an existing natural gas system, mixed with the predominantly methane natural gas; hydrogen, weight-for-weight, produces more heat when burned than any other fuel;
It can be combined with nitrogen to produce ammonia, which has many uses and potential uses and is easy to ship around the world;
- Ammonia can be broken down to recover the hydrogen;
- Ammonia can be used to produce nitrogenous fertilisers and explosives;
- Ammonia can be burned in internal combustion engines (with no carbon dioxide emissions);
- Ammonia has many other uses.
Hydrogen can be combined with carbon dioxide to produce methane which is an easily transported gaseous fuel (Example, Methane Fuel Carrier Research and Development, ARENA, CSIRO research);
Hydrogen can be combined with carbon dioxide to produce methanol which is an easily and conveniently stored and transported liquid fuel (Example, George Olah CO2 to Renewable Methanol Plant, Reykjanes;
Hydrogen can be burned to power turbines and generate electricity;
It can be stored in underground formations for later use;
It can fuel vehicles using fuel cells.

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This section added 2019/10/18

Challenges and disadvantages of hydrogen

Hydrogen does have a number of unique challenges relating to its production, storage, transport and use.

The production of hydrogen, as of the time of writing this section if it is to be done sustainably, is not energy efficient.
While a kilogram of hydrogen can yield more energy when combined with oxygen than a kilogram of any other common fuel (and far more energy than a kilogram of batteries), it does require a lot of space to store. Liquifying it requires extremely low temperatures and storing it as a gas under very high pressure requires heavy tanks. It can be stored as metal hydrides, but this too requires heavy storage systems.

Hydrogen can be converted to ammonia by combining it with nitrogen. Ammonia is much easier to store and transport than is hydrogen. Ammonia can easily be converted back into hydrogen and nitrogen, but there are challenges in removing the nitrogen and all traces of the ammonia. Of course energy is required in both conversions.
If hydrogen is in contact with iron or steel (especially when under high pressure?) it can combine with the iron to form brittle iron hydrides that then weaken the metal.
The very low density of hydrogen gas makes piping it or transporting it by road, rail or ship, expensive.
Burning hydrogen to produce electricity is inefficient (as is burning any fuel to produce electricity). Using it in a fuel-cell system is also inefficient. (However, burning it to produce heat is very efficient.)
Any leakage of hydrogen into the atmosphere would indirectly increase the level of greenhouse gasses and exacerbate climate change. Quoting from an article in The Conversation (by Graeme Pearman and Michael Prather, 2020/08/10):
"In the atmosphere, ozone and water vapour react with sunlight to produce what are known as hydroxyl radicals. These powerful oxidants react with and help remove other chemicals released into the atmosphere via natural and human processes, such as burning fossil fuels. One of these chemicals is methane, a potent greenhouse gas.

But hydrogen also reacts with hydroxyl radicals and, in doing so, reduces their concentration. Any hydrogen leaked into the atmosphere – such as during production, transport or at the point of use – could cause this reaction. This would reduce the number of hydroxyl radicals available for their important cleansing function."
So if the world is to get the greatest advantage out of a potential hydrogen economy, leakage of hydrogen into the atmosphere will need to be minimised.

Related pages on external sites

Research; Flow-through electrodes make hydrogen 50 times faster

Bloomberg Green; Hyundai Hydrogen Chief on Why the Company Bet on Fuel Cells.

Fuelling world sustainably synthesising ammonia using less energy; Mirage News, Tokyo Institute of Technology research, April 2020.

Bottling Australian sunshine; South Korea is keen to enter the hydrogen future; Stockhead, April 2020; "... a joint report between the Australian Academy of Technology and Engineering (ATSE) and South Korea’s prestigious National Academy of Engineering Korea (NAEK) has indicated that Australia could be a world-leading hydrogen exporter by 2030."

National Hydrogen Roadmap – CSIRO; Bruce S, Temminghoff M, Hayward J, Schmidt E, Munnings C, Palfreyman D, Hartley P (2018)
"Clean hydrogen is a versatile energy carrier and feedstock that can enable deep decarbonisation across the energy and industrial sectors."

Hydrogen for Australia's Future: A briefing paper for the COAG Energy Council; Prepared by the Hydrogen Strategy Group chaired by Australia's Chief Scientist, Alan Finkel, August 2018.
Vision Statement: Our vision is a future in which hydrogen provides economic benefits to Australia through export revenue and new industries and jobs, supports the transition to low emissions energy across electricity, heating, transport and industry, improves energy system resilience and increases consumer choice.
The Key Opportunity: To capture the hydrogen export market and associated benefits in the domestic economy.

16 renewable hydrogen projects backed by ARENA grants, written by Sophie Vorrath in Renew Economy, 2018/09/06. "... ARENA said the research and development projects targeted by the funding covered a diverse range of solutions, with at least one from each point in the supply chain: production, hydrogen carrier, and end use."

Queensland to invest in exploring hydrogen energy, AAP, 2018/05/31. "The Queensland government has announced $750,000 will be allocated in next month's state budget to start developing hydrogen as a viable renewable energy source."

Carbon Commentary, by Chris Goodall; Hydrogen made by the electrolysis of water is now cost competitive and gives us another building block for the low-carbon economy.

Electrolysis of Water; Wikipedia

Assessment of the cost of hydrogen from photovoltaic electricity, Australian Renewable Energy Authority.

Hydrogen production from coal gasification, USA Office of Energy Efficiency and Renewable Energy.

AGL's media release on the hair-brained brown coal to hydrogen project in Victoria. AGL recognises the need for carbon capture and storage if the project goes full scale. They have not providing funding for the pilot coal-to-hydrogen project to be built in Victoria but are providing a site and the needed coal. AGL is the biggest producer of greenhouse gasses in Australia but is aggressively pursuing sustainable alternatives to coal-fired power generation. They have promised to phase out coal for power generation, but not until 2050, which is far later than needed.

A drone powered by a combination of hydrogen fuel cell, super capacitor and battery. University of Sydney aerospace engineering PhD candidate Andrew Gong, September 2018.

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Related pages on this site

Australia's energy future

Base load power: the facts

Climate change

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Hydrogen; power to gas, in Australia

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