Army fort in Arizona diversifies energy sources with new solar array

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A small solar array just outside the border of Fort Huachuca, Ariz., provides power for buildings at the Southern Arizona Veterans Memorial Cemetery. The new array will be just down the road. (Jeff Benzak photo)

By Jeff Benzak

FORT HUACHUCA, Ariz. – A few years ago on Christmas Day, the U.S. Army installation at Fort Huachuca in Arizona lost power for eight hours. Home to about 6,500 active-duty personnel, Fort Huachuca is the headquarters of the U.S. Army Intelligence Center and its fleet of unmanned aerial vehicles, or drones, so the power loss underscored the need for the fort to take a new approach to how it sources energy.

In February 2015, the Army dedicated a new solar array at the fort. The 18-megawatt array will generate enough electricity to supply about a quarter of the base’s needs. During peak daylight hours, all of the fort’s electricity will be generated by the sun.

The project is the largest solar array on any Department of Defense installation. It was built on a few hundred acres of flat, underutilized Sonoran desert scrubland near the fort’s main gate. In a model expected to be replicated on other bases, the local utility, Tucson Electric Power, leased the land from the Army and funded, built, and operates the array. E. ON Renewables was the project developer.

“Energy is an installation priority,” said Maj. Gen. Robert Ashley, Fort Huachuca’s commanding general. “The project goes beyond the megawatts produced. It reflects our continued commitment to southern Arizona and energy security. The project will provide reliable access to electricity for daily operations and missions going forward.”

Fort Huachuca spends about $10 million a year on energy for the 500 buildings across the installation, some of which date to the late 1800s, when the post was founded as American settlers moved west. Recently, these energy costs have declined about 7 percent thanks to a mild winter and energy efficiency measures, with the March 2014 bill coming in at about $700,000. The solar array is expected to drive those costs down further. The energy will not be fed back into the grid – it will go directly to the fort’s substation.

E. ON hired local contractors from the neighboring town of Sierra Vista as well as from other towns across the state. A slightly smaller solar array at Davis-Monthan Air Force Base in Tucson required about 130 workers. At Fort Huachuca, workers were needed throughout 2014 to grub and level the land, drive pilings about 7-8 feet into the ground, operate heavy machinery, install thousands of solar panels, and replant native grasses.

“It will look like a big construction site,” said Bill Hill, the fort’s energy manager, shortly before the groundbreaking.

The array will lessen the fort’s reliance on nearby power plants operated by Tucson Electric Power that are at least partly powered by fossil fuels. Hill said part of Tucson Electric Power’s motivation for building the array is to meet Arizona’s Renewable Energy Standard, which calls for 15 percent of the state’s electricity mix to be generated by renewables by 2025.

The Army, meanwhile, benefits from increased energy security by having power generation closer to the base.

“It’s a win-win-win,” Hill said. “We couldn’t have done it any other way.”

Jeff Benzak is a communications associate at Environmental Entrepreneurs (E2).



Fort Huachuca is located about 12 miles from the Mexican border in a remote stretch of the Sonoran desert. Base officials say illegal immigrants sometimes cross the border at night and head to the lights of the base thinking it’s Phoenix, which is actually about 200 miles further north.

The base was founded in 1877 both to protect American settlers from Apache raids and to guard the border from Mexican incursions. It has been home to Buffalo Soldiers, a predominantly black cavalry regiment, as well as Apache scouts, the last of who was still serving in the Army in the 1930s. The fort’s name, Huachuca (Hwa-CHOO-Cah), is derived from the Apache description of the area: “place of thunder.” Situated along the western end of a large basin rimmed by 5,000-foot mountains, loud, crackling thunder bounces off the basin’s walls during the summer monsoon season.

This basin-and-range geography is what dictates the fort’s main military mission – Army intelligence. The remoteness and surrounding mountains form a natural barrier that protects the fort’s airspace from outside radio and electronic interference. This allows the Army to test advancements in technologies like the GPS, which was partly developed at Fort Huachuca. Helping to commercialize and drive down costs of new technologies that grow the private sector is a role the Army and the DoD have long played. With their commitment to solar at Fort Huachuca, the same thing is happening with renewable energy.

— Environmental Entrepreneurs



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Colonel Smith Middle School at Fort Huachuca, Ariz., is one of the most energy efficient schools in the state. Daylighting, wind turbines, LED lighting, and other energy efficiency and renewable energy measures keep electric bills low without compromising the learning environment. While the school is operated by the local school district, it is located entirely on the Army post. “If more schools are built following the same design features as CSMS, that will be great for the students, the parents and, with respect to energy conservation, for our environment,” said Tim Quinn, Fort Huachuca Accommodation School Board president. (Jeff Benzak photo)