Davis-Monthan Air Force Base dedicated a 16.4-megawatt photovoltaic solar array on Thursday that is the largest of its kind on any Department of Defense installation.

Davis-Monthan signed an agreement with solar developer SunEdison LLC in 2010 to design, finance, build, operate and maintain the array on 170 acres of underutilized land at two locations on the base.

The D-M array is bigger than the previous largest Air Force and military installation, a 14-megawatt array built at Nellis Air Force Base in Nevada in 2007. The Pentagon has even larger systems in the works, including a 20-megawatt system planned for Fort Bliss, Texas, and a 500-megawatt plant planned for Fort Irwin in Southern California.

D-M’s system will meet about 35 percent of the base’s electricity requirements at an “economically beneficial rate” for 25 years, reducing base utility costs by an average of $500,000 annually, D-M officials said.

According to the Air Force, D-M pays 8.6 cents per kilowatt-hour for commercial electricity, while the rate for the power supplied from the solar array will be 4.5 cents, increasing by 1.5 percent per year.

Elsewhere at D-M, the Soaring Heights housing community has 6 megawatts worth of its own photovoltaics.

The Air Force is the largest consumer of energy in the federal government, spending more than $9 billion annually in electricity and fuel costs, D-M says. The branch has a goal to increase its renewable-energy consumption to 25 percent of the total by 2025.

Speakers at Thursday’s event included Col. Kevin Blanchard, commander of the 355th Fighter Wing at D-M; Maricela Solis, district director for U.S. Rep. Ron Barber, D-Ariz.; Bob Powell, president of North American solar for SunEdison; and David Hutchens, president of Tucson Electric Power Co.

Retired astronaut Mark Kelly spoke on behalf of his wife, former Rep. Gabrielle Giffords, a longtime supporter of solar energy.