This Google X spin-off backed by Bill Gates is offering a pathway to heat and cool your home with clean energy
Kathy Hannun, founder and president at Dandelion Energy, on December 13th, 2019, on location at a geothermal heat pump installation in Westchester, NY.

Kathy Hannun wants to help reduce greenhouse gas emissions by making geothermal heat pumps mainstream. Hannun, 34, spent seven years working at Alphabet's X lab (formerly Google X), known as the tech giant's "moonshot factory." She helped launch several projects, like Project Loon, more than one of which were shut down because they were deemed not commercially viable. The experience taught Hannun that she wanted to focus her energy on ambitious innovations that are ready to be scaled and brought to market. It led her to geothermal heat pumps, which she started working on at X with a project called Tiny Lime. In 2017, Hannun and another X colleague, James Quazi, spun out Tiny Lime into start-up, Dandelion Energy. In February, Dandelion announced it has raised $30 million in a funding round led by Breakthrough Energy Ventures, the clean energy investment fund started by Bill Gates which includes money from Jeff Bezos, Michael Bloomberg, Ray Dalio, and others. Now Hannun and Dandelion are working to take geothermal heat pumps, an energy-saving way of heating and cooling homes, mainstream. They are doing this by making it easier and cheaper for people to have geothermal heat pumps installed in their homes, allowing homeowners to move on from furnace systems that rely on oil, natural gas and propane.

Kathy Hannun is holding up a vial containing methanol made from carbon dioxide extracted from seawater combined with hydrogen made with the prototype Google X Project Foghorn machine. Photo Courtesy Google X

Why geothermal heat pumps?

Geothermal heat pumps heat and cool indoor spaces in a more energy efficient manner than other heating and cooling systems. They can also be operated with electricity, offering a pathway to heating and cooling internal spaces with clean energy. Geothermal heat pumps work by using an underground pipe system to move heat between the earth and your home. They are used for both heating and cooling — fluid running through the pipes picks up heat from the ground in the winter and deposits excess heat in the summer. While geothermal heat pumps use energy to operate, the energy they use to operate is less than is used by non-geothermal systems (exactly how much varies). These pumps can use renewable, carbon-free energy, like solar or wind. "Geothermal heat pumps are part of the pathway to zero [greenhouse gasses]," says Forrest Meggers, a professor of architecture at Princeton University and founder of Cooling and Heating for Architecturally Optimized Systems Lab. Geothermal heat pumps also have the potential, with the addition of thermal or battery storage, to store heating and cooling energy for a home to draw on at a later time, which could help "decouple home thermal demand from energy demand," Megger says. That means the potential to put less strain on energy grids — something that could have benefitted Texas during the blackouts caused by the cold spell in February. (Dandelion Energy does not currently add battery storage as an option.) Other selling points for heat pumps include saving money on monthly fuel bills, quieter and more steady indoor heating and cooling, and they do not run the risk of causing carbon monoxide poisoning, according to Dandelion.

The Dandelion solution

A green future for geothermal heat pumps