This story originally appeared on EOS and is part of Covering the Climate Now, a global journalistic collaboration promoting coverage of climate stories.
Many countries are betting on solar panels as they transition to clean energy. But the technology requires much more space than conventional fossil fuel plants to produce the same amount of electricity. An emerging solution to save space is to float the panels in water, a method called "flotovoltaics." Scientists believe this new method could help increase global solar power and fight climate change, but its impact on the environment remains largely unexplored.
The world's first commercial photovoltaic system was installed in an irrigation pond at a winery in California in 2008. Since then, hundreds of megawatts of large plants have been built on China's hydroelectric lakes and reservoirs, and many more are planned in Southeast Asia and beyond. Brazil.
"Photovoltaics is one of the fastest-growing energy generation technologies today and a promising low-carbon energy source," said Rafael Almeida, an aquatic ecosystem ecologist at the University of Texas at Rio Grande Valley.
Almeida explained that floating panels should ideally be placed on man-made bodies of water, such as irrigation canals and hydroelectric dams, and should not occupy land that could actually be used for nature conservation or food production. Hydroelectric reservoirs have the advantage of power distribution infrastructure.
Almeida and colleagues calculated the potential of floating voltaic use for different countries around the world based on the surface area of their hydroelectric reservoirs. They found that countries in Africa and the Americas have the highest potential for energy production with floating-voltaic technology. For example, Brazil and Canada could become leaders in this field, as they need only 5% reservoir coverage to meet all their solar energy needs by mid-century. The scientists presented their findings on December 12 at the fall meeting of the American Geophysical Union.
"We must seriously consider all options to increase low-carbon energy production while reducing land use intensity," Almeida said. "But we need to understand how to mitigate the unwanted social and environmental consequences," he adds, explaining that we still know very little about the impact of large areas of water with solar panels.
Regina Nobre, a freshwater ecologist at Paul Sabatier University in Toulouse, France, agrees. Nobre was not involved in the latest study, but was part of a pioneering effort to monitor the ecological effects of tidal energy on Europe's ancient gravel lakes. These pits were originally created for mining, but are usually abandoned and filled with river water and are home to a variety of aquatic animals. Nobre does not have results yet, but believes evidence from environmental impact research will be very important for policymakers.
"Technology is advancing rapidly, and we urgently need more information to understand its implications and better guide environmental agencies and public policy," he said.
For one thing, the extensive coverage of the panels can block light in the water, Nobre says, which can alter the diet and reproduction of algae, which can deplete oxygen in the lake and have a cascading effect on the ecosystem, affecting local damage. Fishing and other wildlife. .
Another possibility is that the panels could prevent the exchange of greenhouse gases such as methane between the water and the atmosphere, possibly offsetting the benefits of carbonation. But the actual impact cannot be predicted without research and may vary with different panel designs, coverage areas and landscapes, the two scientists noted.
"We have to take an early approach," Almeida said. "On the one hand, we cannot place many barriers to progress in this potentially important area, but on the other hand, we need to understand the trade-offs and fill in the gaps in our knowledge with further studies."
