Supervolcano Generator
NASA have a backup plan to cool Yellowstone's supervolcano in case it gets close to erupting, by drilling holes in the sides and pumping super-cooled water through the volcano chamber. The exiting water would be heated to around 350°C on the way out from cooling the volcano and on the way into a geo-thermal plant to generate electricity. A win-win, at the cost of $3.46B.