A new study conducted by researchers from Oregon State University (OSU) and the US Geological Survey claims that the environmental impacts of floating solar projects on US installations have not been fully considered.
D3Energy and Ameresco built Utah’s first floating solar project on a retention pond on top of a mountain. D3Energy
The study Published this month, “Modelling Diverse Environmental Responses of Reservoirs to Floating Photovoltaic Systems,” analyzed 11 floating solar projects built in Arkansas, Idaho, Oregon, Ohio, Tennessee and Washington. Researchers found that the floating arrays all lowered the temperature in each body of water, according to a press release, but that effect has different implications for maintaining or damaging aquatic habitats.
“Different reservoirs will respond differently based on factors such as depth, circulation dynamics and the fish species important to management,” said Evan Bredeweg, lead author of the study and a former postdoctoral researcher at Oregon State, in a press release. “There’s no one-size-fits-all formula for designing these systems. It’s ecology — it’s messy.”
Floating solar touts the benefits of reducing land use for construction. There is no civil work, other than anchoring in the bottom or shoreline of a reservoir. Additionally, these arrays have a smaller project footprint than ground-mounted arrays of comparable size.
“If you think about it, you already have a nice flat surface,” says David Goldenberg, project development engineer at Ameresco, in a solar project case study published in January. “You don’t have to do all this civil work. Like a ground assembly, we would have to move a lot of earth to flatten it.”
By keeping panels above water, these arrays lower temperatures against shade, reducing evaporation and cooling solar panels, making them more efficient. It also inhibits algae activity in warmer waters.
In January, the U.S. Department of Energy’s National Renewable Energy Laboratory published a study claim that floating solar built on federal and regulated reservoirs in the US could produce enough energy to power approximately 100 million homes.
However, the OSU study urges that more attention should be paid to the impact floating solar projects have on ecosystems. And the NREL study acknowledges that it doesn’t take into account how animal activity could affect the development of floating solar energy. Introducing artificially induced temperature changes into water bodies can affect fish habitats. OSU researchers recommended that floating solar projects should be designed to best meet the needs of each reservoir and its ecosystem.
“History has shown that large-scale modifications to freshwater ecosystems, such as hydroelectric dams, can have unforeseen and lasting consequences,” said Bredeweg.
