Duke Energy installed major rooftop solar system at Keck Observatory in Hawaii

Duke Energy’s REC Solar completed the world’s largest commercial solar system installed at the highest altitude.

The rooftop solar project is at the W. M. Keck Observatory on the Big Island of Hawaii, located near the summit of Mauna Kea, a dormant volcano on the Big Island of Hawaii. The installation is at an altitude of 13,600 feet.

It is located on the rooftop of Keck Observatory’s telescope facility, between the domes of the twin Keck I and Keck II. The system will produce 259.1 MWh of energy each year, which will reduce the observatory’s electric power needs by about 10-15 percent.

“Incorporating renewable energy generators such as solar PV is important to Keck’s core values of stewardship and service. It will reduce our reliance on electricity derived mainly from fossil fuels, which underscores our efforts to be good stewards of the planet,” project lead Mark Devenot, an infrastructure specialist at Keck Observatory, said.

The rooftop system is made up of a 133-kW photovoltaic array and 332 solar panels. A major challenge was attaching the PV array to this roof, which has no structural framework to anchor the system. The solar system was custom engineered for the unique ballasted roof design and to support high winds. The team also had to deal with working at high altitudes, which averaged 40 percent less oxygen than at sea level.

“Incorporating rooftop solar at Keck Observatory has been a special experience for the REC Solar team due to the project’s focus on science, safety, and innovation,” Dan Alcombright, managing director, growth implementation at Duke Energy, said. “Our team remained respectful of land and wind limitations throughout construction and leveraged our local experience and detailed weather data to engineer solar with specialized mechanical attachments that can handle the wind gusts and climate of a Pacific island at high altitude. We’re pleased to be able to provide Keck with a viable energy solution that positively impacts both their organization and the environment.”

The panels will catch more photons at this high altitude and produce more energy than at sea-level locations. Also, having 40 percent less atmosphere makes for efficient solar energy generation.

Duke Energy’s REC Solar is a subsidiary of Duke Energy Renewables. REC Solar has installed over 800 solar, energy storage, microgrid, and EV fleet charging sites for commercial, public sector, and utility-scale customers