NREL researchers detail potential of floating solar arrays

Researchers from the National Renewable Energy Laboratory (NREL) recently published a paper describing the potential of floating solar photovoltaics (PV) in the United States.

The researchers estimated that floating solar PV installed on the more than 24,000 man-made U.S. reservoirs could generate approximately 10 percent of the nation’s annual electricity production.

The paper, Floating PV: Assessing the Technical Potential of Photovoltaic Systems on Man-Made Water Bodies in the Continental U.S., was published in the journal Environmental Science & Technology. NREL researchers Jordan Macknick, Robert Spencer, Alexandra Aznar, Adam Warren, and Matthew Reese authored the paper.

As of December 2017, the United States had only installed seven floating PV sites, while there were more than 100 floating sites globally.

“In the United States, it’s been a niche application; where in other places, it’s really been a necessity,” Macknick, the lead energy-water-land analyst for NREL and principal investigator of the project said. “We’re expecting it to take off in the United States, especially in areas that are land-constrained and where there’s a major conflict between solar encroaching on farmland.”

Approximately 2.1 million hectares of land could be saved by installing solar panels on water instead of on the ground, the researchers found. The use of floating PV can also reduce water evaporation and algae growth, and operating floating PV alongside hydroelectric facilities can yield increased energy output and cost savings because of the existing transmission infrastructure, according to the NREL team.

“Floating solar is a new industry enabled by the rapid drop in the price of solar PV modules,” Warren, director of NREL’s Integrated Applications Center, said. “The cost of acquiring and developing land is becoming a larger part of the cost of a solar project. In some places, like islands, the price of land is quite high, and we are seeing a rapid adoption of floating solar.”

Funding for the analysis came from NREL’s Laboratory Directed Research and Development program.