Hydrogen was the future once. But while the UK was quick off the mark in investigating the potential of H2 for heating homes, much of the original plans have been abandoned in favour of solar, wind and electrification, writes Ros Taylor. Methane gas heats more than three-quarters of British homes, making it one of the main sources of CO2 emissions. In 2017 the UK launched a programme called Hy4Heat to investigate whether it was feasible to move British households over from methane gas to hydrogen.