Dairies may benefit from geothermal energy plants, say Arizona scientists. And the U.S. Department of Energy has given a grant to several state universities and businesses to help farmers and other entities explore possible uses of geothermal energy — heat from the earth’s core. The benefit of this alternative energy, backers say, is that it’s available 24 hours a day, seven days a week. Users don’t have to wait for the wind to blow or the sun to shine, and the water can be returned to the aquifer once the heat is used. For dairies, geothermal technology has the potential to dramatically reduce the energy cost associated with heating water to properly clean milking equipment.