Bright idea: Floating solar
Water panels gain popularity in Asia and begin to appear in US localities that like the fit
When Joe Seaman-Graves, the city planner for the working-class town of Cohoes, New York, Googled the term “floating solar,” he didn’t even know it was a thing.
What he did know is that his tiny town needed an affordable way to get electricity and had no extra land. But looking at a map, one feature stood out.
“We have this 14-acre water reservoir,” he said.
Seaman-Graves soon found the reservoir could hold enough solar panels to power all the municipal buildings and streetlights, saving the city more than $500,000 each year. He had stumbled upon a form of clean energy that is steeply ramping up.
Floating solar panel systems are beginning to boom in the United States after rapid growth in Asia. They’re attractive not just for their clean power and lack of a land footprint, but because they also conserve water by preventing evaporation.
A study published in the journal Nature Sustainability in March found that thousands of cities — more than 6,000 in 124 countries — could generate an amount equal to all their electricity demand using floating solar, making it a climate solution to be taken seriously. In the process, they could save roughly enough water each year to fill 40 million Olympic-size swimming pools.
Zhenzhong Zeng, a contributor on that study and associate professor at the Southern University of Science and Technology in Shenzhen, China, said in the United States, counties across Florida, Nevada and California have the potential to generate more power than they use. Of course, they would need a mix of energy to actually provide power all hours of the day, Zeng said.
The concept of floating solar is simple: Attach panels onto rafts so they float on water instead of blocking off land that could be used for agriculture or buildings. The panels are sealed and act as a lid that brings evaporation down to nearly zero, benefiting regions like California that repeatedly experience periods of drought. The water also keeps the panels cool, allowing them to generate more electricity than their landmounted counterparts, which lose efficiency when they get too hot.
“We hear from our installers that they like it because it’s something different,” said Chris Bartle, director of sales and marketing for floating solar company Ciel & Terre, which has built 270 projects in 30 countries. “They get to go out on the water as opposed to on a rooftop. We joke that you need life jackets instead of ladders,” he said.
Bartle’s company has launched 28 floating solar projects in the U.S.
Limited land may have spurred some countries in Asia like Japan and Malaysia to expand floating solar, and other countries just took advantage of the steep plunge in prices for solar that has dramatically changed the economic picture for solar adoption globally.
A report by London-based Fairfield Market Research says the region currently accounts for 73% of revenue from floating solar and “spearheads the global landscape” — but predicts that policy incentives in North America and Europe will spur significant growth.
High costs up front remain a barrier. Bartle said floating solar costs 10% to 15% more than land solar initially, but owners save money in the long run. The technology can’t operate on fast-moving water.