Hydrogen gas produced by geological processes beneath Earth's surface has been touted as a promising clean energy source. A new study provides the first solid evidence that it could be a practical and commercially viable option for decarbonizing the grid. Hydrogen is an energy-dense fuel that produces only water when burned. But today, the vast majority of industrial hydrogen is manufactured using fossil fuels in an energy intensive process, negating its green credentials. While there’s hope renewable energy could one day power the process and provide a reliable source of green hydrogen, that technology is still a long way from commercial viability. Recently though, there has been growing excitement about the possibility of vast natural hydrogen reserves stored deep underground. Several large deposits have been discovered and estimates suggest that trillions of tons of the gas could be sitting beneath our feet.…