Kathy Hannun brought something to geothermal heating and cooling technology that it hasn’t had before: affordability.
In the past, using heat from the earth has been something of a luxury good—systems were expensive and had to be custom-built for the house they were heating, with prices to build and install them in New York reaching well above $60,000.
“The earth is a relatively constant temperature of 50 °F year-round once you get down about six feet and below, lasting hundreds of feet down,” she says. Using ground loops filled with water mixed with a propylene glycol solution, it’s possible to exchange heat very efficiently between the earth and the home that’s being heated or cooled. “Horizontal geothermal systems put the loops in about 10 feet below ground,” she explains. “This requires a lot of surface and rips up a large section of ground.” Getting ground loops installed in the yard has in the past been quite an ordeal, requiring massive drilling equipment and significant surface damage. Instead, using technological innovations pioneered by the oil and gas industry, Hannun’s Dandelion Energy has created a drilling system that limits the amount of land needed and the surface damage done to achieve the same result.
Dandelion can install a system for a total cost of less than $30,000.
Hannun came to geothermal while working as a product manager for Google X. Her goal: take geothermal “down the path that solar has been down over the past two decades, and bring it from a very niche technology to one that replaces furnaces and boilers.”