Hydrogen fuel produced using renewable power could finally turn the aviation industry green
Stories about “green hydrogen” fly across my desk almost daily, claiming it to be the answer to some of our most difficult energy challenges. But what is “green hydrogen?” And why are some experts hailing as one of the most exciting new trends in sustainable power?
Simply put, what makes hydrogen fuel “green” isn’t what it is, but how it is made. Hydrogen is made by using electricity to electrolyze H2O — water — separating the hydrogen atom within it from its molecular twin oxygen. It takes a lot of power, and green hydrogen is made using power from renewable sources rather than fossil fuels.
In the past, the main challenge of producing hydrogen this way has been its energy intensity and therefore its cost of production. But as renewable energy costs plummet around the world, the potential for making this zero carbon energy source is now both possible and scalable for industrial use.
From low carbon steel to long haul sea and road transport, green hydrogen has the potential to be a game-changer. But perhaps the best possible use for green hydrogen lies in aviation fuel. A new report by an Australian government funded science organization, in partnership with Boeing, says that hydrogen made with renewable energy could solve the problem of pollution-heavy aviation fuel by as early as 2050.
The report by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) lays out a roadmap to transitioning to hydrogen-based fuel in stages, with a complete transformation of the sector by 2050. But the report says that it could begin to reduce the sector’s greenhouse gas emissions within the next five years. CSIRO continues that green hydrogen could be used in minimal ways almost immediately to replace airport equipment currently running on liquid fuels and batteries, with hydrogen-powered fuel cell alternatives.
More importantly, in the medium term, hydrogen could be used as the basis for the production of zero emissions “electro-fuels” where hydrogen is combined with carbon dioxide to provide jet-fuel replacements for existing airplanes. As planes are usually in use long term, electro-fuels used in existing planes could be a key to transitioning from polluting fuel and help decarbonize the sector as early as 2030.
Dr. Christopher Munnings, Senior Research Scientist at CSIRO and co-author of the report, says this is possible right now and that hydrogen offers a clear alternative to polluting aviation fuel.
“Aviation is one of the hard nuts to crack on the climate front so this is an important area where we need to speed up alternatives”
“Aviation is one of the hard nuts to crack on the climate front so this is an important area where we need to speed up alternatives,” he said. “The challenge with the switch to electrofuels is cost. It’s more expensive to produce than extracting and refining oil for aviation fuel.”
In 2009, the International Air Transport Association (IATA) adopted a target of a 50% reduction of 2005 CO2 emissions levels by 2050, with no increase in net emissions after 2020. This has been widely adopted by the aviation industry, but — despite the global drop in air travel due to the Covid-19 pandemic — the industry expects a tripling in the number of flights globally at that time. To achieve these kinds of emissions reductions would mean a 90% reduction of greenhouse gas emissions overall. As pressure mounts to follow the limits of the Paris Agreement, the added cost and a drive for rapid innovation may well be justified in the new climate economy.
Green hydrogen horizons
Munnings notes that alternative aviation fuels are already being used in space travel, by Europe and California for air travel, and in some forms by the auto industry.
Other major factors in low carbon air travel (and what the CSIRO sees as it’s long-term hydrogen solution) are liquid hydrogen fuel and also major changes in the design and weight of airplanes themselves.
“We’ve already seen a steep change in efficiency in planes, such as the 787 Dreamliner,” Munnings says. A plane that could fly using liquid hydrogen for longer-haul flights would need to look quite different, be significantly lighter, and carry a higher volume of fuel.”
Munnings argues that hope lies in the fact that all transport sectors — airlines, shipping and the auto industry — need solutions like green hydrogen. They also need to find ways to produce, store, and transport it, meaning that demand is high and solutions are needed urgently.
“The solutions may be slightly different for each sector,” Munnings says. “But the scale of the need for alternatives should give scientists and investors reason to move ahead.”
Innovation down under
So why is green hydrogen innovation coming out of Australia, of all places?
“Australia has the lowest cost renewable energy in the world so we’ll have the lowest cost green hydrogen,” Munnings says. “In an odd way, without a great deal of government intervention, Australia can be far more economically driven because it has to be.”
“Australia has the lowest cost renewable energy in the world so we’ll have the lowest cost green hydrogen”
A new academic paper by Australia’s Crawford School in Canberra suggests that green hydrogen in Australia is fast becoming cost competitive against hydrogen produced using fossil fuels. It’s also more likely to reach cost parity with increased and more efficient production.
Investment arms, including the Australian government-funded Clean Energy Finance Corporation (CEFC), are investing in the emerging green hydrogen sector, and there is national interest in green hydrogen as a fuel source for producing steel. At least three major hydrogen projects, including a $300 million trial project to inject hydrogen into gas works in Queensland, a $3.5 million South Australian project, and a similar-sized green hydrogen plant to replace coal-based electricity generation are underway in Western Australia.
Australia isn’t alone in the development of green hydrogen. California-based SGH2 Energy Global is building the world’s biggest green hydrogen plant that will use plastic waste to fuel a biogas facility to create green hydrogen for electricity and transport. The UK, Germany, Netherlands, Dubai, South Korea, and Japan also have green hydrogen projects in train. Hydrogen-fueled buses are now on the road in Brazil, a country that has led the world in alternative vehicle fuels. In late August, Sweden opened the first fossil-free hydrogen-powered steel plant — Hydrogen Breakthrough Ironmaking Technology, a.k.a. HYBRIT — using green hydrogen rather than coal power.
A recent report by the Institute for Energy Economic and Financial Analysis (IEEFA) says that 50 new green hydrogen projects have been announced in Europe, Asia, and Australia in the last year, including five just last month. The report warns that investment shortfalls and a lack of government backing may slow the sector down while demand is leaping ahead. The projects currently in development are likely to only produce 3 million tonnes of green hydrogen a year, but the forecast for demand is 8.7 million tonnes a year by 2030 according to the report. The International Energy Agency (IEA) recently launched a report tracking global green hydrogen progress country by country and encouraged countries to use Covid-19 stimulus investment to ramp up green hydrogen production to meet growing demand.
Some experts caution against moving too quickly into hydrogen without understanding the full climate change and environmental impact. In an article in The Conversation, Australian experts Graeme Pearman and Michael Prather argue that using hydrogen as fuel might make global warming worse by affecting chemical reactions in the atmosphere.
“We must know more about this risk before we dive headlong into the hydrogen transition”
“We must know more about this risk before we dive headlong into the hydrogen transition,” the article argues, noting that hydrogen reacts with hydroxyl radicals — ozone and water vapor reacting with sunlight — that play an important role in removing other chemicals released into the atmosphere, including from the burning of fossil fuels. Any hydrogen leaked into the atmosphere in the making or use of hydrogen for energy could react with hydroxyl radicals, reducing their concentration. Monitoring of hydrogen shows that concentrations are on the rise and scientists are not sure why. Pearman and Prather note that hydrogen may increase global warming by 20-30% that of methane if leaked into the atmosphere.
Munnings notes that more scientific research focus — and clearly international information sharing and government involvement — is needed. “The airline industry is committed to finding low carbon alternatives and has made some significant commitments to reducing emissions,” he says. “We need to help stimulate the scientific community to find solutions.”