While floating solar — the innovative method of placing solar panels on water surfaces — shows great promise in terms of efficiency and conserving agricultural and protected lands, a recent experiment highlights some environmental compromises.
While floating solar — the innovative method of placing solar panels on water surfaces — shows great promise in terms of efficiency and conserving agricultural and protected lands, a recent experiment highlights some environmental compromises.
In a groundbreaking field study focused on the environmental consequences of floating solar, recently published in Environmental Science and Technology, researchers discovered that the use of floating solar panels led to an increase in greenhouse gas emissions from small ponds by nearly 27%.
“Numerous papers have been published on floating solar, primarily using modeling and projections,” stated Steven Grodsky, assistant professor of natural resources and the environment. “This is the first manipulative study providing real empirical evidence. It’s revealing the actual outcomes we observed, which showed an increase in greenhouse gas emissions from ponds equipped with floating solar.”
Grodsky and his team applied solar panels to three ponds at the Cornell Experimental Pond Facility, covering 70% of their surface area. They observed that, right from the start, emissions of methane and carbon dioxide rose by 26.8% compared to ponds without solar panels, while levels of dissolved oxygen in the ponds significantly dropped.
“By installing floating solar, you’re considerably diminishing oxygen levels available for aquatic life, disrupting ecological processes, affecting decomposition, and altering microbe activity, as well as how wind interacts with the water’s surface. Everything is interrelated,” Grodsky explained.
This research is particularly significant as floating solar projects in the U.S. are largely taking place on small lakes and ponds, according to Grodsky. It’s also timely for New York state, which is contemplating floating solar as a potential alternative to land-based solar, sparking ongoing discussions and investigations.
Despite the concerns, the study reveals some positive aspects of floating solar: when assessing total emissions throughout the project’s lifecycle—from site development to maintenance and disposal—floating solar’s greenhouse gas emissions (per kilowatt hour of energy produced) are still likely to be lower than those of terrestrial solar and fossil fuel sources. The 70% coverage represents an upper limit, and the researchers proposed strategies to mitigate the negative impacts, such as reducing the area covered or implementing water agitation systems, although further research is essential.
“Looking back at energy transitions, like from wood to fossil fuels, the focus was solely on energy production, neglecting environmental effects, which has led us to issues like environmental injustice and climate change,” Grodsky noted. “The goal here is to address these issues early and rethink how we manage this energy transition.”
