Ellen Phiddian
Cosmos science journalist
On Sunday, the Queensland government announced plans to build one of the world’s largest renewable energy manufacturing facilities in the world, at Gladstone in the state’s north.
Backed by Fortescue Future Industries (FFI), which is chaired by mining magnate Andrew Forrest, the facility will be making equipment to create green hydrogen, which can be used as a renewable fuel source. The first stage of the plan is an electrolyser facility, which FFI aims to have online by early 2023.
Why is FFI focussing on electrolysers first, and what else will they be making in Gladstone? What is an electrolyser, anyway, and why do we need one to make green hydrogen? Read on to find out.
Why electrolysers?
The facility will be making equipment to create hydrogen, which can be used as a fuel source – and, critically for renewable energy, stored and transported more easily than electricity. (Our Cosmos Briefing on hydrogen fuel explains this in more detail).
Where do electrolysers fit into this?
“Electrolysis is the key to getting green hydrogen,” explains Dr Jessica Allen, a researcher in electrochemical engineering at the University of Newcastle.
Hydrogen can come from a variety of sources. One is by separating water (H2O) into hydrogen and oxygen using electricity – this process is called electrolysis.
“As long as the electricity is supplied by renewable energy, it will be green hydrogen,” says Allen. “Green” hydrogen is made without any greenhouse gas emissions involved in the process.
This is important, because most industrial hydrogen is not currently made via electrolysis: it’s made from coal or natural gas, emitting carbon dioxide in the process.
Associate Professor Adam Osseiran, an electrical engineer at Edith Cowan University and president of the Hydrogen Society, describes electrolysers as “the first step” in the green hydrogen production process. Electrolysers attached to wind or solar farms could ‘store’ the renewable electricity generated by the farm by making hydrogen using renewable electricity.
How do they work?
“An electrolyser is made up of three main things,” explains Allen.
There are two electrodes: when both are inserted into water, hydrogen will form at one and oxygen at the other. If you did high school chemistry at any point in the last 60 years, you may remember doing this at a small scale – possibly with a battery and lead pencils.
Aside from size, an industrial electrolyser has one key additional safety concern: hydrogen gas is highly flammable, and a high concentration of oxygen makes it more explosive.
“So the third thing that you need is a separator that separates the two electrodes but still allows for the reactions to happen,” says Allen.
This separator is a membrane, usually made of polymers. Allen says that while new designs of electrolyser don’t require many precious materials to make, this polymer membrane may need to be imported.
What would an electrolyser attached to a wind farm look like? Allen says that the technology is scalable.
“You can have an electrolyser that sits on a bench, or you can have an electrolyser that’s the size of a room – and then you would have maybe 20 of those electrolysers all in a line,” she says.
What happens to the hydrogen once it’s made?
Once the electrolysers have done their job, the next question is what to do with all the hydrogen. How do you store a flammable gas?
Allen says that while some hydrogen has been stored and transported industrially for decades, the amounts required for feasible energy storage are on a different scale.
“You need some sort of large-scale onsite storage, which becomes quite tricky.”
“One of the ways we’re talking about doing that is using underground salt caverns – they can be naturally occurring, but there’s also work being done in making these synthetic caverns.”
These caverns could “safely store the hydrogen underground in very large quantities”.
The hydrogen could also be reacted with ammonia and stored in liquid form – the proposed Western Green Energy Hub in WA and the Fortescue Green Hydrogen Plant in Tasmania are both planning to do this, as are other renewable energy projects.
Eventually, the hydrogen will be combusted in fuel cells to make electricity – which FFI may also plan to make.
“Once you have the electrolysers produced here, the next step is to use that energy for other production – maybe fuel cells will come next,” says Osseiran.
Why make them onshore?
A renewable energy manufacturing facility is a boon for local jobs – particularly in an area like Gladstone, where many are employed in the stagnating coal industry. But are there other advantages to onshore manufacture?
“It’s interesting that they’re looking at building the electrolysers here in Australia,” says Allen.
“I think it’s actually pretty exciting that we’re not just buying this technology in, because that’s what we’ve done with technologies like photovoltaics and wind turbines for many years now.”
FFI is also planning to manufacture solar cells and wind turbines at Gladstone, once the electrolysers are being produced. Allen thinks this is could be very beneficial.
“In Australia, the silly thing is we’ve got all of these critical minerals and resources that we ship off to be put into components elsewhere, and then we buy the components back.”
Onshore manufacture of electrolysers and other technologies also means that they won’t have to be transported as far.
“We’re basically paying a premium price because they have to be made and then shipped here. And then it also contributes to embedded carbon emissions of those technologies.”
Is it feasible?
FFI plans to be producing and selling electrolysers in 18 months. Given that most green hydrogen strategies don’t plan for hydrogen to be competitive until 2030, is this a logical goal?
Allen and Osseiran both say that, given the right price tag, it should be.
“Things are happening so quickly now, I actually do think that it’s possible for them to do this,” says Allen. “It used to be slow because there was no investment.”
“I think, if you put your money where your mouth is, you can do things in that timeframe,” says Osseiran.
Allen compares hydrogen technology to photovoltaics (solar power).
“[Photovoltaics] started off really expensive, and then as the uptake and investment increased the price dropped and they became a lot cheaper and readily available. It seems like the same thing is happening for hydrogen technology.”
This is particularly the case for electrolyser technology, which has been around since the 1970s.
“It’s never had this degree of investment, and that’s what drives it down,” says Allen.