 Here's how a hydrogen-powered regional airliner works. The hydrogen comes in using modular capsules, eliminating the need for a whole new fueling infrastructure and also speeding up the fueling process. The liquid hydrogen gets gasified using excess heat from the powertrain and fed to the fuel cells along with ambient air flowing through a compressor. The fuel cells take hydrogen and air and produce electricity and water. Power is the only waste product, and the electricity is used to power an electric motor which turns the propeller. The fuel cell and motor generate quite a bit of heat. Some of this heat is useful, but the rest we eliminate using microtube radiators, the same technology used on Formula One racecars. We've solved the hard problems, so you will see hydrogen passenger airplanes in regional service in the next few years for a guilt-free, zero-carbon flying experience.