Using a heat pump to heat homes is 6 times more efficient than using green hydrogen: a heat pump delivers ~300 kilowatts of heat per 100 kilowatts of renewable electricity input (via 3-4x coefficient of performance from work-to-heat conversion), while green hydrogen delivers only ~50 kilowatts of heat (due to 75% electrolysis efficiency, 50% fuel cell efficiency, and transport/compression losses), requiring 6 times more offshore wind turbines for equivalent heating via hydrogen.