Quietly humming away on a missile base on the west side of the Hawaiian island of Kauai is the U.S. military’s largest 100 percent clean energy microgrid—a self-sufficient, solar-powered energy system that is the product of a collaboration between the National Renewable Energy Laboratory (NREL) and Department of Defense (DOD) to deploy distributed energy resources that support energy resilience.

The Navy’s Pacific Missile Range Facility in Kauai is the world’s largest instrumented multi-environmental missile testing range, supporting the development and testing of U.S. weapons systems.

Thanks to the NREL-DOD collaboration, the facility now includes a 14 MW solar facility along with a 70 MWh battery storage system that can store energy on-site, allowing the base to be self-sufficient should the island’s electric grid go down.

The two agencies came together in 2019 to improve the sustainability and capabilities of DOD technology and facilities. NREL has helped to increase energy resilience at the Marine Corps Air Station Miramar near San Diego, Tyndall Air Force Base near Panama City, Florida, and the Army’s Fort Carson near Colorado Springs, Colorado.

“This is a great example of the power of strong partnerships supporting innovation and clean energy system deployment,” said NREL Applied Engineering group manager Mike Callahan. “Today, the entire island of Kauai operates routinely on 100 percent renewable energy, primarily solar, and the base now has an on-site power source that isn't dependent on fuel shipments.”

The installation of the energy system, known as a microgrid, comes following years of testing, research, and development by NREL, which has used the technology for similar purposes at Air Station Miramar. These microgrids allow military bases to use more reliable and resilient energy solutions, while also utilizing cleaner tech, such as solar arrays.

Along with the DOD, NREL partnered on the Pacific Missile Range Facility project with the island’s electric utility, Kauai Island Utility Cooperative (KIUC), and global energy company AES.