HILL AIR FORCE BASE, Utah — What do you do when the power goes out for an extended period of time?

The construction of a new ground-mounted solar array is part of the answer at Hill AFB, as the base works to improve the resilience of the power supplies to itself and reduce its reliance on energy sources outside the fence line.

The goal the Air Force has for its installations is to sustain the ‘critical missions’ for a 30-day grid outage, said Base Energy Manager Nickolas King, 75th Civil Engineer Squadron.

While Hill AFB’s new array by itself won’t reach that goal, when integrated with future micro grid planning and other ongoing energy initiatives, it is a step toward it, King said.

The south-facing, fixed 25-degree tilt system is being installed by Indiana-based Energy Solutions Group. The 3.55 MW solar array will produce 17 times more energy than the existing array on the west side of the installation.

Pat Roemer, Energy Systems Group program manager, said fixed systems require less maintenance and are less expensive to install than other types of arrays. He said systems that track the sun provide only marginal gains in efficiency.

Power generated by the new array will be used as it is produced. In addition, it will provide Hill AFB with increased energy production, King said, which will be particularly useful during peak electrical consumption periods in the summer months.

The array is being installed through an Energy Savings Performance Contract, which means there is no upfront costs to the government. The contractor finances the project, in this case for a 23-year term, and is compensated through the proven savings and guaranteed performance of the project.

The Energy Systems Group will have personnel on site to maintain and operate the system for the term of that agreement. The array is expected to be installed and online by early spring.