US zero carbon-emissions aviation company Universal Hydrogen has announced that it has used one of its proprietary modular liquid hydrogen storage and transport ‘capsules’ to successfully power its megawatt-class fuel cell powertrain. The test was run on the company’s ground-based ‘iron bird’ test rig. (The company also has a flying test bed, a modified 40-passenger De Havilland Canada Dash 8 regional airliner, on which it has been flight testing its fuel cell powertrain since March last year.)

“This is the largest fuel cell powertrain ever to run on liquid hydrogen, making it another in a series of ‘firsts’ for Universal Hydrogen,” reported company president and CTO Mark Cousin. The module powered the drivetrain for more than one hour and 40 minutes, a time that simulated the flight profile of a regional airliner.

The module can actually hold enough liquid hydrogen to fuel the powertrain for three hours, at full power. Two such modules would give an ATR72 regional airliner (retrofitted with Universal’s fuel cell powertrains in place of its conventional turboprop engines) a usable range of 500 nautical miles (926 km), that is, excluding the extra range needed to allow the aircraft to divert to another airport, if need be.

Each module or capsule is self-contained, internally incorporating all the systems needed to manage and store (without boil-off) cryogenic hydrogen. Externally, what faces the user is a straightforward container interface (compatible with current intermodal transport and airport cargo handling equipment) and leak-proof quick-connect system to allow the module’s easy installation and removal from an aircraft.

When installed in an aircraft, the modules become its fuel tanks. Each module has a capacity of about 200 kg of liquid hydrogen and also incorporates the systems needed to convert the extremely cold liquid hydrogen into warm gaseous hydrogen, which serves as the fuel for the powertrain.

“This end-to-end demonstration of a hydrogen molecule moving from our filler/dispenser into our storage module and then into our powertrain is the first time that all the pieces of our product portfolio for regional aviation have come together,” highlighted company co-founder and CEO Paul Eremenko. “The next step is to upgrade our flight testbed to fly the powertrain fuelled by our modules.”

Recently, Universal also successfully demonstrated its module technology in a ground-based aviation application: as a hydrogen-powered charger for airport ground support equipment.

The company’s liquid hydrogen module was developed at its design and engineering facility in Toulouse, France. The iron bird is located, and the tests were undertaken, at the Mojave Air & Spaceport, California, in the US.