Wind turbines stand tall and mesmerize with their motion. Solar cells bask in the sparkling sun. Meanwhile, hidden down in the dark dirty underworld, a compelling technology sits quietly and gets no respect. Once installed it largely goes unseen and, it seems, it’s equally invisible in the world of clean technology press, venture funding and government R&D funding. Yet this technology provides some of the most intriguing economic returns available for reducing a building’s net energy consumption and I would welcome the right opportunity to fund an exciting business in this category.
What is this Rodney Dangerfield of cleantech? Geothermal heat pumps, also referred to as ground source heat pumps or geoexchange. Anyone who has gone down a hundred feet or so in a cave on a hot day probably noticed how nice and cool it was down there. That is because in most geology, a zone of nearly constant 55-degree Fahrenheit temperature exists 50-200 feet below the ground we walk on. Even at shallower depths the temperature hovers within a much narrower range than on the surface. Geoexchange is technology that uses the constant temperature and huge heat sink that the earth represents to generate heat in the wintertime …
