In the first commercial use of a General Motors fuel-cell vehicle in the United States, the U.S. Postal Service will lease a 2002 HydroGEN 3 minivan as part of a two-year test in Washington and its suburbs. The U.S. Postal Service vehicles will be refueled at a Washington Shell Hydrogen gas station that will open in September. GM said it plans to use the station’s hydrogen pump for a fleet of fuel-cell vehicles in the nation’s capital.