It’s safe to say there’s a buzz around hydrogen. The element is potentially a revolutionary new energy source. It is one of the possible solutions to reach net zero.
Hydrogen has been used for decades across a wide range of industries. But there’s still a degree of uncertainty around its origins, applications and handling.
That’s why the Australian Hydrogen Council[Link will open in a new window] has led collaborations with the Department of Climate Change, Energy, Environment and Water (DCCEEW), state and territory governments, and our Hydrogen Industry Mission[Link will open in a new window] to compile a list of frequently asked hydrogen questions.
From these, we've developed a hydrogen FAQ tool called HyFAQ[Link will open in a new window].
HyFAQ is an interactive collection of information on hydrogen. It includes details about its properties, uses and applications, safety and regulations and economic and environmental impacts.
HyFAQ is for researchers, industry, government stakeholders and anyone interested in hydrogen. It will increase understanding of how hydrogen can play a crucial part in Australia’s current and future energy mix.
It will be ever-evolving given how quickly the hydrogen industry – and technology underpinning it – is developing. It's a great start for anybody wanting to learn more about this versatile energy source. Here's a selection of frequently asked questions.
What is hydrogen?
Hydrogen is the most abundant chemical substance in the universe. It is everywhere from the air we breathe to the water we drink. H is the chemical symbol for hydrogen.
When combined with oxygen, hydrogen creates a water molecule (H2O). The word ‘hydrogen’ is derived from ancient Greek and means ‘water-maker’.
When combined with carbon, hydrogen creates methane (CH4). Liberated from the molecules, we can use this to create energy.
Hydrogen is versatile. A range of sources produce hydrogen and physically convert it between its gaseous and liquid states. It can also be chemically converted into other forms, such as ammonia.
When renewable or zero-carbon sources produce hydrogen, it becomes a zero-emission energy source. Once produced, it can be stored for later use at any time and in any place. It can power public transportation such as buses, private transportation such as cars and trucks, and in heating and cooling buildings. It also has industrial uses such as producing fertiliser and synthetic fuels and for manufacturing steel and aluminium.
All of these applications (and more) are being developed around the world.
Why is everyone talking about hydrogen?
Hydrogen has been around for a long time, but people are talking about it more now because the cost of renewable energy technologies is coming down. This reduces the cost of making clean or green hydrogen. This means hydrogen has potential to play a major part in the future energy mix.
How much hydrogen exists?
Some hydrogen gas exists in underground reservoirs. However, our understanding of this is still very recent so we do not know the volume available. We understand hydrogen is everywhere, but not in its pure form. This means it needs to be separated from other elements. This is how the hydrogen industry produces hydrogen. The amount that can be made is technically close to infinite, at least relative to global needs.
Is hydrogen safe?
Hydrogen has been safely produced, stored, and moved around the world since the 1950s. This occurs mostly in the petroleum processing and fertilizer sectors, but also in food production, the space industry, and in industrial chemicals and metals. There are existing standards in place to produce, store, transport and use hydrogen safely.
Hydrogen does require controls to facilitate its safe use, but this is no different than needing to establish safety protocols for other fuels. When handled correctly, hydrogen is as safe as any of its alternatives. If not handled or stored correctly, hydrogen can combust. But the same is also true of natural gas, petrol or diesel.
One of the properties that makes hydrogen relatively safe when compared to other fuels is that it is the lightest element. When hydrogen is released (because of a leak or spill) it disperses rapidly and therefore is unlikely to ignite. If it does ignite, a hydrogen flame burns out quickly and is non-toxic.
There is ongoing work to ensure safety through the development of hydrogen codes and standards, and in developing and delivering training for people who may come into contact with hydrogen.
What are the green, grey and blue hydrogen types?
Green or renewable hydrogen
Green hydrogen[Link will open in a new window] generally refers to the production of hydrogen from water via electrolysis using renewable electricity (like wind, solar or hydro). An alternative name, understood as equivalent, is renewable hydrogen. Green hydrogen production emits no greenhouse gases.
Grey hydrogen
We refer to hydrogen made from natural gas or coal as grey (or brown/black hydrogen).
Natural gas produces most of the hydrogen the world uses today using a process called steam methane reformation. In this process, water enters a furnace, producing steam at a very high temperature. This steam reacts with natural gas, producing hydrogen and carbon monoxide. A further process then reacts the carbon monoxide with more water to make additional hydrogen and carbon dioxide.
We can also make hydrogen from coal using a process called coal gasification. To do so, coal is put into a high-pressure ‘gasifier’ to release carbon, hydrogen and oxygen.
Blue hydrogen
Similar to grey hydrogen, we make blue hydrogen or low carbon hydrogen with natural gas or coal. However, the carbon dioxide produced in the process is captured and stored (CCS, or CCUS for carbon capture utilisation and storage). The National Hydrogen Strategy relates to clean hydrogen, which uses renewable energy or fossil fuels with substantial carbon capture and storage to produce hydrogen.
How much water do we need to produce 1 kilogram of hydrogen?
Hydrogen production, like all industrial processes, will require access to a reliable water supply. Under optimal conditions it should be possible to produce one kg of hydrogen using as little as nine litres of treated water in a newly installed electrolyser, or five litres of treated water using steam methane reforming. However, raw water requirements will be more than this, and figures also vary depending on technology and locational choices.
It will be important for both planners and developers of large hydrogen production facilities to consider how their water choices and use can best align with local cultural and environmental considerations and existing water planning to meet the needs of other users of water resources.
How do we export hydrogen?
We can export hydrogen in many ways. The current industry and government discussions about hydrogen consider two main ways to export it in high volumes.
Liquid export
This requires cooling gaseous hydrogen down to -273 degrees Celsius and transporting the liquid hydrogen at this cryogenic temperature between countries.
Chemical export
This method uses another chemical, most likely ammonia, which might need to be converted back to hydrogen at the receiving end.
There are other options as well, and pros and cons to different approaches. However, all options require hydrogen to be initially produced economically at a significant scale.
When will industry use hydrogen?
Hydrogen is already an important feedstock for producing chemicals like ammonia and methanol. Additionally, it is used in oil refining. The question is when existing fossil fuel-derived hydrogen might be replaced with clean or renewable hydrogen. There is work occurring to understand and plan for this shift. But it will be a long-term prospect while the industry is still emerging and prices are high.
How ready is the hydrogen industry to meet future demand?
The clean and renewable hydrogen industry is developing, with more than 100 projects announced (by September 2022) and more than $1.5 billion in government funding. The industry and governments are working together to create the foundation for a hydrogen market.
However, the task ahead is significant and there is much for industry to do. For example, meeting Australia's more optimistic hydrogen production scenarios in the National Hydrogen Strategy[Link will open in a new window] would mean having several electrolysers (the machine to make renewable hydrogen) at 1 gigawatt capacity each. In 2022, the largest electrolyser in Australia is 1.25 megawatt, which means we need to see 800 times the size of this electrolyser in 7.5 years.
How will hydrogen assist in reducing emissions from transport?
When battery electric and fuel cell electric vehicles run on renewable electricity - either stored in the battery or as hydrogen - there are no carbon emissions or other pollution produced. Hydrogen represents an opportunity for us to decarbonise hard to reach transport modes[Link will open in a new window] that we cannot address with battery electric vehicles. In particular this includes aviation, marine, rail and heavy road vehicles.