After its first year of operation, the solar array at Davis-Monthan Air Force Base in Tucson, Ariz., has far surpassed officials’ expectations, generating more electricity and producing more savings than anticipated.
“We expected the array to provide 35 percent of our total power needs. However, our calculations show it is providing well over 40 percent of our total need, and over 100 percent of our daytime energy usage,” said Lt. Col. Brian Stumpe, commander of the 355th Civil Engineer Squadron.
“This amounts to a $500,000-per-year savings for Davis-Monthan and the Air Force,” Stumpe told Air Force Civil Engineer Center (AFCEC) Public Affairs.
The Air Force’s largest operational solar array has a 16.4-megawatt capacity and was built through a 25-year power purchase agreement with SunEdison LLC. The agreement calls for the base to pay 4.5 cents per kilowatt-hour, with an annual increase of 1.5 percent. The base previously paid 8.6 cents per kWh.
In its first 10 months, the array produced 33.1 million kWh of electricity, enough to power over 3,600 homes, according to AFCEC.
In addition to cost savings, the array has provided Davis-Monthan energy resiliency, reliability and security. And the savings free up resources that can be reallocated to other priorities.
“Since we don’t own the project, our civil engineers are freed up to focus on the core mission of operating and sustaining the air base and generating air power,” Stumpe said.
The array also has benefited the local utility, Tucson Electric Power, by allowing it to surpass its 4 percent goal for meeting the state’s renewable energy standard.
The array at Davis-Monthan won’t remain the Air Force’s largest indefinitely. Two solar arrays in the works will be larger — a 19-megawatt expansion of an existing 14.7-megawatt array under construction at Nellis AFB, Nev., and a 20-megawatt solar farm in the proposal phase at Vandenberg AFB, Calif.
“The Air Force has a goal that every base will implement some sort of renewable energy generation,” Stumpe said.