1982: In “Using Nature's Boiler,” associate editor George M. Fodor explored the technical developments in ground water heat pumps. Mechanical contractors were described as key players, of course: “Well drillers don't have the contacts, especially in the commercial sector, to make the ground water heat pump market boom. “Commercial clients turn to mechanical systems contractors, who thus become the key to whether or not this market will reach its potential,” Fodor wrote.
Global Data reports that worldwide geothermal energy capacity will grow 89% between now and 2015.