Hydrogen-electric powertrain

A propulsion system in which fuel cells turn hydrogen into electricity to drive electric motors and propellers.

• A fuel cell combines hydrogen with oxygen from the air across a membrane, producing electricity, heat and water.
• Hydrogen holds about 33 kWh per kg, nearly three times jet fuel and over 100 times today's best batteries.
• But even liquefied at −253 °C it takes about four times the volume of jet fuel, and the insulated tanks add weight.
• Fuel cells need large radiators to shed heat, and airports would need new hydrogen production and fuelling infrastructure.