A new type of geothermal power plant has sprung up in the Nevada desert. Yet it has one distinct advantage—a core of magma that will stay liquid for billions of years, making geothermal energy both reliable and virtually unlimited. The future of geothermal energy could be unlimited if we continue to innovate ways to capture the power inside Earth’s crust. In fact, geothermal energy powers about a third of Iceland’s electricity needs and about 90 percent of its homes. So far, the Boston-based company has completed some successful tests, and is now planning to bore a hole 12.4 miles deep over 100 days.