Washington Post: On a vacant piece of land near Nellis Air Force Base in Nevada, the promise of solar energy has collided into the demands of military training. And a solar project that would have featured a vast field of mirrors, a molten-salt storage facility and a 600-foot “power tower” appears to be heading for defeat. In 2007, a Los Angeles firm called SolarReserve proposed the construction of a $700 million solar thermal power plant, covering two square miles near the Nevada Air Force base, …