ZeroAvia, already deploying hydrogen as a main part of its flight program, is exploring the use of cryo-compressor technology to deliver more energy dense H2 for longer flights. If we think of gasoline or Diesel fuel as “Cream of Energy Soups,” we might understand their preeminence as energy carriers. A U. S. gallon (3.8 liters) of Gasoline for instance, contains about 33.4 kilowatt-hours of energy. Compare this to a state-of-the-art lithium battery, which tops out at around 0.5 kW-hrs. A Diesel engine might be able to convert 50 percent of that to useful work, with the rest going to waste heat. A gasoline engine fares even worse, extracting perhaps 30 percent as work and 70 percent as waste heat. Electric Motors, however, are highly energy efficient, some extracting up to 97 percent of a battery’s stored energy. If one uses hydrogen instead of batteries, one can reach parity with the amount of energy available to spin the propellers. As early …
E9X: 90 Passengers, 480 Battery Miles
What can carry 90 passenger 480 miles on battery power alone? Such a query flies in the face of others’ efforts to hybridize medium-range flight, but may be answered by Delft-based Elysian Aircraft. Their eight-motored, battery-powered E9X uses a backup turbogenerator only for reserves, putting a level of trust in the 365 Watt-hour per kilogram cells buried within the long, slender wing for safe transit. Graham Warwick’s Article Graham Warwick, writing for Aviationweek.com, explains that, “Breaking with traditional design principles, Delft-based Elysian says it has found design space where a large electric aircraft looks viable with near-term battery technology.” That kind of range for that large an aircraft seems extreme, but the E9X’s developers are using currently-available batteries to achieve their goals. Reynard de Vries, director of design and engineering at Elysian, explains, “If you want to make a significant impact on the sector as a whole, then you need to electrify flights up to 1,000 km [620 mi.]. Then …
Airbus and Perlan Check out Hydrogen
Airbus, through its partnership with the Perlan Project, is investigating how to clean vapor trails from the high-flown paths traversed by airliners. Through its pair of Blue Condor jet-powered sailplanes, Airbus and Perlan are working toward a contrail-measuring mission in 2024. Hydrogen, the most abundant element in the universe, has been a rarity in the aviation world, other than in well-publicized events involving gas-fueled conflagrations. (Whether the H2 carrying the Hindenburg aloft or the fabric skin covering the great ship’s frame caused the fire at Lakehurst, New Jersey in 1937 is still somewhat controversial.) Regardless, the disaster brought about a deep mistrust of hydrogen that persists to this day. Airbus, along with the Perlan Project, looks forward to exploiting H2’s advantages while overcoming its undeserved stigma and surprising issues. Perlan’s Greater Mission The Perlan Project has achieved an enviable string of record flights culminating in the 2018 altitude record of 76,114 feet. Carrying CubeSats filled with science experiments developed by …
The Cellsius AC4 Hydrogen Project
The Cellsius AC4 Lightwing is a capable microlight aircraft popular in Europe. As part of a project to clean up aviation, it will fly on hydrogen, and for good distances if students at ETH Zurich* are successful in their project. Students are modifying a Lightwing to run on pressurized H2, and crafting motor, fuel system, tanks, power electronics, and battery backup system to make a coordinated, custom-fitted craft. It will stay aloft for two hours and emit nothing but water vapor. The project’s web site spells out the students’ ambitions. “Our powertrain consists of many components that together can get an aircraft into the air. “To make this a reality, we develop the majority of our components ourselves, tailored to our requirements.” Components include a radial-flux motor, unusual in that most electric aircraft motors are axial flux. Students worked with e+a (Elektromaschinen und Antriebe) AG to design and construct the unit. With that motor, students helped design a matching inverter …
Solar Airship One – a Grand Voyage Awaits
Having circumnavigated the world by balloon and solar-powered aircraft, Bertrand Piccard is ready to make a third around-the-world flight – this time in Solar Airship One, powered by the sun and hydrogen fuel cells. Able to make the 40,000 kilometer (24,855 mile) trip in one gigantic hop, the 151 meters (495.4 feet) long craft will be borne aloft on 50,000 cubic meters (1,766,000 cubic feet) of helium. Unlike his lonely stints at the controls of Solar Impulse 2, Piccard will be joined by two worthy co-pilots; Dorine Bourneton, “The first disabled woman to become an aerobatic pilot (Bourneton was severely injured at age 16 in an aircraft accident) and Michel Tognini, a former French Air Force fighter pilot and European Space Agency astronaut (Tognini has been twice to space, in 1992 and 1999).” The Craft Its helium sealed in 15 large gas bags that emulate the shape of the airship, the ship carries 50,000 cubic meters (1.77 million cubic feet) …
H2Fly Achieves HEAVEN’s Goal
H2Fly has an historic aircraft in its fleet, the HY4, as part of the HEAVEN program to, “Demonstrate the use of liquid, cryogenic hydrogen in aircraft.” Originally the G4, the craft won the NASA Green Flight Challenge in 2011, posting a passenger mile per gallon efficiency of 403.5 – equivalent to driving your loaded Prius from San Francisco to Los Angeles on under four gallons of fuel. Resurrected as the HY4 and flown on gaseous hydrogen, the craft has been reconfigured to fly on liquid hydrogen, expanding its range significantly. According to the HEAVEN program, “The hydrogen-electric ‘HY4’ demonstrator aircraft took off from Maribor, Slovenia, and saw safe and efficient operation throughout multiple flight tests.” Announced September 7, these were the first piloted flights of a liquid hydrogen fueled aircraft. Four flights, including one that lasted over three hours, “Lay the foundation for long-range, emissions-free flight, with liquid hydrogen doubling the range of the HY4 aircraft to 1,500[kilometers], compared to …
ZeroAvia Turbo Charges a Fuel Cell
Turbo chargers were an early method of increasing power at altitude and that ZeroAvia is crafting for modern electric, fuel-cell powered aircraft. Mechanical Turbochargers During WWII, your editor’s father was a crew chief and occasional flight engineer on C-47’s, B-17’s, and B-24’s. The bombers had turbo-charged engines to increase power as noted below. (This is just part one of three training films, all on YouTube, giving some indication of the difficulties pilots faced in pre-electronic times.) The flight manual for the B-17 includes the following notes on the turbochargers. “The B-17F has four 1200 Hp Wright Cyclone Model R-1820-97 engines of the 9-cylinder, radial, air-cooled type with a 16-to-9 gear ratio. “Each engine has a turbo-supercharger to boost manifold pressure for takeoff and maintain sea-level pressure at high altitude.” B-24’s and other similar craft had the same type of system. (ZeroAvia’s rough equivalent is much quieter and a loss less smoky.) The manual notes the F models had manual control of …
Silicon and Sugar Make Better Batteries
Two groups of researchers in South Korea and America have added silicon and sugar as ways of gaining more energy from two different types of batteries. The 10X Battery at Last? Researchers at Pohang University of Science & Technology (POSTECH) in South Korea have developed a “layering-charged, polymer-based stable high-capacity anode material.” POSTECH professors Soojin Park (Department of Chemistry) and Youn Soo Kim (Department of Materials Science and Engineering) and Professor Jaegeon Ryu (Department of Chemical and Biomolecular Engineering) of Sogang University think their discovery could increase current electric vehicle range “at least 10-fold.” As noted in this blog many times, the idea of a 10X battery has been a matter of intense research from Yi Cui at Stanford and his research partner Jaephil Cho in South Korea, along with John Goodenough at Rice University and Jeff Dahn at Canada’s Dalhousie University – among others. Silicon and Polymeric Benders One of the bigger problems with using silicon in a battery …
Green Hydrogen from Scrap Metal and Water?
Can we make green hydrogen (or other energy sources) from scrap we otherwise throw away? One of the frequently announced “breakthroughs” recurrently finding its way to our attention is that scrap food or farm waste has found its way to becoming aviation fuel, for instance. United and Alaska Airlines have flown aircraft powered by biofuels produced from food waste by suppliers at SEATAC airport in Seattle, Washington. Hydrogen is undergoing a growth spurt. The U. S. Department of Energy explains, “Hydrogen is an energy carrier that can be used to store, move, and deliver energy produced from other sources.” Green hydrogen seems to be an answer to many demands. It comes from splitting water, and if produced through clean means, is a carbon neutral to carbon negative product. Stainless Steel Powder and Water Dr. Guy Ben Hamu, Head of the Department of Mechanical Engineering at Sami Shamoon College of Engineering, explains the process uses H2 trapping, something usually related to …
ZeroAvia to Supply Surcar with Hydrogen Floatplanes
An Island-Hopping Customer Surcar Airlines is an enterprise based in the Canary Islands which hopes to serve its island routes with ZeroAvia-motored, hydrogen-fueled DeHavilland Twin Otters. But not right away. Starting with conventionally-powered turbine twins, Surcar is working on a process, “Based on starting something totally new and that touches so many sectors at the same time. “Today we confirm that we have signed an agreement with@zeroavia to fly its ZA600 hydrogen-electric engines in order to operate ecological flights. “We will operate Twin Otter seaplanes updated with the ZA600 propulsion system on our sightseeing flights.” This 600 kilowatt (804 horsepower) system is now being tested and certified for aircraft seating nine to 19 passengers. “This implies the commitment to lead the electrification of aviation in the Canary Islands and achieve zero-emission flights in the archipelago.” This ambition drives the airline to follow, and possibly lead in the European Union’s aim to, “…Reduce greenhouse gas emissions by 55 percent by 2030 …










