Springer Basel Ag, Basel, 2023
New fuel and propulsion technologies are being proposed to find suitable alternatives to fossil fuels and new green energy production methods, such as batterypowered and hydrogen-powered aircraft, hybrid systems, and synthetic fuels. Various processes can produce hydrogen, but achieving a low maximum take-off mass is the biggest challenge. Fuel cell aircraft have a low power-to-weight ratio, and the cost of depreciation, interest, and insurance is proportional to the price of the aircraft; also, a viable and environmentally friendly alternative to conventional aircraft, with safety considerations, regulatory issues, ground infrastructure, and government and public acceptance.