If a geothermal well could tap into a reservoir of supercritical fluids and use them to spin a turbine on the surface, it would be one of the most energy-dense forms of renewable power in the world. There’s treasure buried deep beneath the viridescent foothills of Tuscany’s Apennine Mountains, where the stark metal trusses of the Venelle-2 drilling tower mark its location like an X on a map. This geothermal well reaches nearly two miles beneath the surface to a region where temperatures and pressures are so high that rock begins to bend. Here, conditions are ripe for supercritical geothermal fluids, mineral-rich water that exhibits characteristics of both a liquid and a gas. It’s not exactly gold, but if Venelle-2 could tap into a reservoir of supercritical fluids and use them to spin a turbine on the surface, it would be one of the most energy-dense forms of renewable […]