Rolls-Royce and easyJet, a European-based airline, have successfully tested a hydrogen-powered jet engine, the two companies announced in a press release on Tuesday. The pair say the goal is to curb emissions by 2050 and said the ground test marks “the world’s first run of a modern aero engine on hydrogen.”
The test used a converted Rolls-Royce AE 2100-A regional aircraft engine to carry out the tests at an outdoor facility at MoD Bosombe Down in the UK.
Flights are one of the most carbon-intensive forms of travel, and airline emissions have a big impact on the planet. The Energy Industry Review reported the Réseau Action Climate Association found that as of February 2022, aviation is responsible for five percent of global greenhouse gas emissions. Since these numbers don’t account for plane stopovers, emissions, in reality, may be far higher, reaching upwards of 15 percent of global emissions.
The aviation industry says it’s trying to reduce emissions by working to develop planes that use alternative fuels, like hydrogen, for air travel. Hydrogen’s appeal is in its ability to produce water vapor rather than carbon dioxide, making Rolls-Royce and easyJet’s experiment significant. In recent years, several difficult-to-decarbonize industries, like airlines, have invested heavily in hydrogen technologies as they work to reduce their emissions.
Hydrogen is far from being a silver bullet, however. The fuel is, currently, prohibitively expensive and is in short supply. Hydrogen is also difficult to store, according to the U.S. Department of Energy, because it “requires high pressures, low temperatures, or chemical processes to be stored compactly.”
And when it comes to emissions, not all hydrogen types are created equal. Separating hydrogen from other elements requires a lot of energy, and what kind of energy is used is pretty important. If hydrogen is created using fossil fuels—what’s known as “gray” or “blue” hydrogen—studies have shown that the end result’s fossil fuel footprint can be astronomically high. If the hydrogen-fueled jets are to be effective in reducing emissions, they will need to run on what’s known as “green” hydrogen, which is made with renewable power like solar and wind. The easyJet and Rolls-Royce test was conducted with hydrogen fuel made from wind and tidal power, both renewable sources, making its fuel “green” hydrogen.
Airlines will also be faced with the difficulty of introducing and certifying new aircraft designs to accommodate hydrogen jet fuel, and aircraft manufacturers will need to redesign planes with larger fuel tanks, according to the International Air Transport Association. And flights are going to need a lot more hydrogen than other types of fuels: a Boeing 747 jumbo jet requires more than 1 million liters of hydrogen to travel the same distance as 250,000 liters of jet fuel, The Guardian reports.
Despite any drawbacks, Rolls-Royce and easyJet say they are planning a second set of tests with the long-term aim to carry out in-flight tests. However, there is still a long way to go before hydrogen jet fuel can be advanced and is likely to only initially be useful on short-distance flights up to 1,864 miles. A 2020 European Union report estimates hydrogen-fueled planes could hit the market as soon as 2035, The Verge reported.
“The success of this hydrogen test is an exciting milestone. We only announced our partnership with easyJet in July and we are already off to an incredible start with this landmark achievement,” Rolls-Royce Chief Technology Officer Grazia Vittadini said in the press release.
He continued, “We are pushing the boundaries to discover the zero carbon possibilities of hydrogen, which could help reshape the future of flight.”