Researchers at the National Renewable Energy Laboratory (NREL) estimate that floating solar photovoltaics (PV) on the more than 24,000 man-made reservoirs could generate about a tenth of the country’s annual electricity production.

NREL

Image: Floating PV being installed in Walden, Colorado. Photo: Courtesy of Dennnis Schroeder/NREL

The findings of NREL were published in the journal Environmental Science & Technology. The first installation of floating solar was completed 10 years ago on pontoons on an irrigation pond in Napa Valley, California. But, the idea had not received widespread acceptance across the country, the report noted.

In the US, the primary focus has been on large-scale, ground-mounted solar panels, with only seven floating PV sites as of December last year

The report said that floating solar are being deployed more abroad, with more than 100 sites as of the end of last year.

NREL lead energy-water-land analyst and principal investigator of the project that produced the paper ‘Floating PV: Assessing the Technical Potential of Photovoltaic Systems on Man-Made Water Bodies in the Continental U.S.’ Jordan Macknick said: “In the United States, it’s been a niche application; where in other places, it’s really been a necessity.

“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.”

Macknick and his NREL co-authors, Robert Spencer, Alexandra Aznar, Adam Warren, and Matthew Reese estimate that nearly 2.1 million hectares of land could be saved if solar panels were installed on water bodies instead of on the ground.

The team has also found that installing floating solar alongside hydroelectric facilities offers increased energy output and cost savings due to the utilization of the existing transmission infrastructure.

NREL’s Integrated Applications Center director Warren said “Floating solar is a new industry enabled by the rapid drop in the price of solar PV modules.

“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.”