New York Times: The business for ground-source heat pumps is so hot that when some people driving in and around Seattle see Gerard Maloney’s EarthHeat van, with the company’s phone number on the side, they call from their cellphones. “Really, we have people doing this,” Mr. Maloney said. Like other energy alternatives, ground-source heat pumps have won new admirers as energy costs have skyrocketed. The pumps, also called geothermal heat pumps, use the relatively constant temperature just below …