Floating solar in U.S. reservoirs could produce 10 percent of the nation’s electricity

Energize Weekly, January 9, 2019

Floating solar panels on 24,000 man-made reservoirs in the U.S. could generate 10 percent of the nation’s electricity and avoid gobbling up 8,100 square miles of land with ground installations.

One of the challenges with large-scale deployment of wind and solar generation is the land requirements but shifting to floating photovoltaics (PV) could offer one solution, according to researchers at the National Renewable Energy Laboratory (NREL).

“In the United States, it’s been a niche application, where in other places, it’s really been a necessity,” said Jordan Macknick, the lead energy-water-land analyst for NREL and principal investigator on the project. “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.”

The findings of the researchers appeared in the journal, Environmental Science & Technology.

The 24,000 reservoirs identified as suitable for floating solar represent 27 percent of the reservoirs and 12 percent of the area of all man-made bodies of water in the contiguous U.S., the study said.

Floating PV systems covering just 27 percent of the bodies of water identified as suitable could produce 10 percent of the country’s current electric generation.

The United States was the first to demonstrate floating PV panels—with an installation 10 years ago on pontoons on an irrigation pond in Napa Valley, Calif.

While the idea has not been widely adopted here, as of December 2017, there were seven floating PV sites in the U.S.—Japan has 56 of the 70 largest floating installations in the world. There are more than 100 worldwide.

The floating PV comes with added benefits, including reduced water evaporation and algae growth in the reservoirs, the researchers said.

The NREL team also found that operating floating PV alongside hydroelectric facilities yields increased energy output and cost savings because of existing transmission infrastructure.

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