A TED Talk, featuring Cindy Taff, who argues that drilling for geothermal heat instead of hydrocarbons can deliver what solar, wind and fossil fuels can’t — clean, renewable power at all times, regardless of weather. She says accessing this resource could lead to 50,000 times more energy than all the world’s oil reserves beneath the Earth, but accessing it requires using the same controversial technology that oil companies spent trillions to develop: fracking. Could this be help solve some of our energy challenges? Watch now.