Academy solar panels save taxpayers $800K in first year

U.S. AIR FORCE ACADEMY, Colo. -- After a year of operation, the data is in. The Academy has received roughly seven and half percent more power than anticipated from the 6-megawatt solar array project that began production last summer.

A total of 18,888 solar panels were installed along 41 acres on the Academy's southeast corner and began operation for renewable energy on July 1, 2011. Since then, the project has provided the Academy 12.5 million kilowatt hours in power when it was originally estimated to provide only 11.6 million kilowatt hours in power.

"The project is finished and now we're reaping the benefits from it," said Russell Hume, a mechanical engineer with the Academy's Directorate of Installations. "We're making sure it produces within a reasonable measure of what we anticipated and we're above what we predicted, so that's good news."

The $18.3-million project was awarded to Colorado Springs Utilities who subcontracted to SunPower Corp. in August 2009 through funds from the American Recovery and Reinvestment Act. Also in 2009, the Academy was chosen as the net zero installation for the Air Force, and this project is one way the Academy has strived to meet the energy goals of the Defense Department's Net Zero Energy Installation initiative.

"The panels have produced 12 percent of the Academy's overall electricity needs," Hume said. "As we target net zero, electrical energy is relatively easy to produce, but thermal energy is much more of a challenge. Our thermal load is currently met by natural gas and a renewable replacement fuel source for natural gas is very difficult to find."

In the first year of operation, the Academy has saved $802,000 in avoided power purchases, Hume said.

"We estimated we would only save $550,000 in direct power savings, so the $802,000 is great news," he added.

The array uses Sunpower Corp.'s T0 tracker technology. The panels don't tilt to the south, like many fixed-axis arrays across the country, but rather remain flat and track the sun as it moves from east to west.

"The panels sit on top of long square tubes connected to motors that draw power directly from the panels and rotate the panels throughout the day. The degree of rotation is based on the normal weather cycle and where the sun should be based on astronomy."

Hume said the main driver of the project has been to save money and allow the Academy to refocus the money spent on utilities toward the direct mission, instead of mission support.

"In these fiscally austere times, we need to focus our resources on the mission. So being green is great, but saving money is equally important" Hume said. "The great thing with energy, and projects like the array, is that it crosses operational and educational boundaries. I have been able to work closely with the Dean of Faculty and other staff to get cadets involved by showing them the solar array site. We want to expose cadets to solar energy so they can take it forward in their Air Force careers and apply it where necessary."

Hume said the Academy continues to take steps in the net zero initiative to meet the Air Force's desire to save on energy costs and meet legislative mandates.

Executive Order 13514 requires that all new federal buildings must be designed to achieve zero net energy by 2030 and after 2030, every building we create is supposed to be net zero, Hume said. Also, beginning in 2025 the National Defense Authorization Act of 2010 requires the Academy to either produce or purchase renewable energy totaling 25 percent of its total energy per year.

The economic life of the array is 30 years, Hume said.

"We're one down and have 29 more to go," Hume said. "At this point, everything is looking good."