Google's 'Moonshot Factory' Is Known for Wild, World-Changing Ideas. Here's What It Took For One of Them to a Become a Real World Startup. Kathy Hannun, the founder of geothermal energy company Dandelion, believed she could make cheap, sustainable home heating and cooling accessible to the masses. Here's what she learned along the way.

Elaine Weir is retired, which means that — apart from the swimming lessons she teaches a few times a week — she has a lot of time on her hands. So in the summer of 2019, when she saw a Facebook ad for the geothermal energy company Dandelion, she called them up to investigate. "I had no intentions of buying this thing," she says, with a conspiratorial cackle. "But my daughter suffers from asthma, so I wanted to do my small part to reduce our footprint. We were considering an electric car, but then I saw this..."

She agreed to let a salesman come to her home, a 100-year-old Tudor in the New York City suburb of Scarsdale. "He explained this and that," she says. "But when he said I could get rid of the air conditioning, that's when my ears perked up." Like many homes, her HVAC system required a giant, noisy set of outdoor AC condenser units. "I said, 'You mean these don't have to be here?' They're right next to my screened-in porch, and I can hear them in the middle of the night, and they're just plain annoying."