Nellis Air Force Base in Nevada, the land of lots of sun and plenty of land, will be home to a 70,000 solar-panel installation which, at 15 megawatts, will be the largest in North America.

The U.S. Air Force on Tuesday said Nellis and SunPower have finished the first phase of the project, which will save the base $1 million a year and roughly $83,000 a month, when fully commissioned.

The SunPower solar panels will be installed on 140 acres of Nellis Air Force base land and use trackers that move the mounted panels to follow the sun during the course of the day. The trackers improve output by 30 percent.