ZeroAvia has ordered Hyzon's zero-emission hydrogen fuel cells and it will test the fuel cell stack through simulated aeroplane duty cycles. The tests will include basic power requirements such as take-off, cruising, landing and taxiing, in addition to strenuous circumstances including rapid changes in altitude. Once the fuel cell stack has passed the ground test programme, the next step will be to flight test it.

TUV Rhineland, a technical certification provider, confirmed that Hyzon's Gen3 fuel cell stack achieves a volumetric power density above 6.0 kW/litre and gravimetric power density more than 5.5 kW/kg, which are key factors in aviation to minimise weight while providing sufficient power for the desired performance. ZeroAvia says this is the reason it selected Hyzon's fuel cell stack.

It achieves the high power density through a combination of proprietary technologies in the Bipolar Plate and Membrane Electrode Assembly (MEA), where electrochemical reactions take place to generate power.

"Hydrogen provides three times higher specific energy content compared to jet fuel, and is over 100 times higher than the best batteries today, making it the only viable option for large scale zero emission aircraft," says Val Miftakhov, founder and CEO of ZeroAvia. "We are always interested in exploring new technologies for our powertrains, and we look forward to seeing how Hyzon fuel cell stacks perform in the demanding aviation applications."

Hyzon is commonly known for its hydrogen-powered heavy-duty trucks, buses and coaches, however it intends to adapt its technology to accommodate aircraft applications.

"The fuel cell stack doesn't care what it powers," comments Hyzon CEO Craig Knight. "Whether it's in an 18-wheeler, crane, train or airplane, the fuel cells operate very much the same way. Aviation is clearly in need of viable zero emission solutions, and hydrogen propulsion via fuel cells offers some unique characteristics to address this significant contributor to global air emissions."