Hidden in a forest south of Bend, Oregon, a first-of-its-kind clean energy project is starting to take shape. Called Project Obsidian, the “superhot” geothermal power plant will deliver 24/7 electricity—and could soon compete on cost with fossil fuels as it pioneers new drilling technology. “Our goal is to be competitive, if not cheaper, than existing sources of baseload power today,” says Matthew Houde, cofounder and chief of staff at Quaise En…