Valero is installing 33 windmills in Texas to supply its refinery with electricity needed to produce gasoline and diesel fuel. The project, scheduled to be completed in August, will produce about 50 megawatts of electricity an hour, the full load required to run the refinery next door. That should cover about half of the refinery's needs. "We didn't build the wind farm so we could get into the wind-energy business. We built the wind farm so we could support the refinery and run it more economically," said Tom Shetina, manager of the facility in Sunray, Texas.