The hydrogen fuel cell could be a game-changer for planes of all sizes, starting with all kinds of private jets.
Will hydrogen fuel cells beat battery engines and biofuels to become the energy source of choice for aviation?
There is a lot of talk about the hydrogen car. Toyota sold 10,000 Miray, its hydrogen car. This fuel produces, as a residue from the operation of hydrogen fuel cells, only water vapor. Let’s see what its advantages are compared to the combustion engine, diesel or petrol, and the electric battery motor, knowing that a hydrogen car would have the same electric motor as a battery car; what changes is the electrical energy for the engine, which would be supplied by the hydrogen fuel cells.
Environmental impact: similar to that of the battery engine, much better than the combustion engine, especially if the hydrogen is produced by electrolysis, for example by using the overcapacity of the wind turbines when the wind is strong, or that of the panels photovoltaic.
Power: no problem, the electric motor can develop thousands of CV.
Autonomy: much better than the battery engine, because with 1 kg of hydrogen a car can travel 100 km.
Price: The Toyota Miray, a mid-size sedan, costs € 75,000, more than twice as expensive as an analog combustion car, and almost twice as expensive as an electric car with batteries.
Price of fuel, hydrogen: it takes around fifteen euros for 1 kg of hydrogen, enough to travel 100 km by car; so taken analogous to that of gasoline, but about six times more expensive than electricity.
The advantages of hydrogen for airplanes
As with trucks, or hydrogen trains already operating in Germany, the larger the engine, the more advantageous hydrogen is. Indeed, the production, storage and distribution of hydrogen requires significant infrastructure which is expensive. But if each hydrogen station can sell significant quantities, as is the case for supplying trucks or electric planes, the investment becomes profitable.
The advantages of hydrogen fuel cells compared to batteries
Although battery-powered electric propulsion offers the promise of a cleaner, quieter sky, this solution is still largely impractical due to the current limitations of battery technologies. Hydrogen fuel cells offer better durability and autonomy than planes powered by electrical systems.
With compressed hydrogen gas storage, you immediately have four to five times the energy density advantage if you compare a 500 kg fuel cell system to a 500 kg battery. When you enter the storage of liquid hydrogen, you have a multiplication factor of 12 to 15.
As the most abundant element on earth, hydrogen is attractive to the aviation industry because of its need to reduce carbon emissions. Fuel cells store compressed hydrogen, which powers the zero-emission electric motor. The only by-product is water vapor.One California company is betting on it. Entrepreneur Val Miftakhov founded ZeroAvia in 2017 to develop a workable hydrogen-fuel-cell powertrain for aircraft. According to Miftakhov, the ZeroAvia system, currently going through flight testing, not only eliminates emissions but will offer much lower operating costs compared to traditional piston and turbine engines.
Miftakhov says that hydrogen fuel-cell technology can be used in the near term, rather than 10 or 20 years down the road. ZeroAvia has installed a prototype 260-kilowatt powertrain on two, single-engine Piper PA46 aircraft. Test flights began last year in California. On one of the planes, the hydrogen will be stored in above-wing, pylon-mounted tanks. Miftakhov, who founded the electric vehicle-charging company eMotorWerks, says introducing hydrogen to aviation offers distinct advantages over using it in automobiles, since far fewer hydrogen-distribution stations will be needed to support aircraft. ZeroAvia’s fuel cell solution also uses existing aircraft, airports and air traffic control systems, versus the need to develop a new aviation infrastructure for urban air mobility and autonomous, electrically powered air taxis.
The real promise of hydrogen fuel cell propulsion
The real promise of hydrogen fuel cell propulsion lies in its relative scalability to larger aircraft, says Miftakhov, from existing regional aircraft up through narrow-body airliners. “You’re going to have a real problem in 2050 if you don’t do something right now,” he says. “The useful life of a commercial aircraft is 30 years, so any purchase locks the industry into an emissions trajectory for 30 years. If your target is 2050, you want some semblance of sustainability today.”
Aviation accounts for 12 percent of annual emissions in the transportation sector and that number is on its way to doubling by 2050. ZeroAvia’s goal is to see its hydrogen fuel-cell powertrain installed over the next two or three years on regional aircraft that fly routes of about 500 miles.
Hydrogen is produced by an electrolyzer and then transferred to the fuel cells on the airplane. ZeroAvia says that hydrogen storage will be more practical for airplanes than cars because of fewer number of airports.