If you asked how ubiquitous electric vehicles would be a decade ago, it's hard to imagine their current rise into the mainstream. So what's next for clean energy innovation? Kathy Hannun, co-founder of Dandelion Energy, believes the next frontier is geothermal heat pumps. At Dandelion, she's working to bring geothermal technology, an energy-saving way of heating and cooling homes, to households across the country. Along the way, Bill Gates' firm led her Series B, and she's been recognized as one of Fast Company’s Most Creative People in Business. Kathy shares why she was a reluctant founder at first, why she believes the adoption of geothermal is inevitable, and how she harnesses a constant need to innovate.