Urban stormwater management ponds are increasingly repurposed for floating solar installations to generate clean power without using valuable land.
Researchers monitored an Orlando stormwater pond where a floating solar array covered under five percent of the water surface.
Local wildlife, including sunfish, turtles, river otters, and amphibians, actively used the pond alongside the array. Shading from the solar panels cut spring near-surface chlorophyll-a levels beneath the covered zone by as much as 80 percent.
Field sampling setup and wildlife coexistence in urban ponds
Field teams evaluated an urban stormwater pond in Orlando, Florida, to measure environmental and biological shifts around floating photovoltaic panels.
The test installation covered less than five percent of the total water surface, leaving most of the pond exposed to natural sunlight and wind mixing.
Researchers evaluated water quality using multiparameter probes and seasonal water-column sampling rather than wildlife tracking equipment. While local fauna such as sunfish, turtles, and river otters were noted as site inhabitants, the study included them only as background context.
Sunfish (Lepomis species) ended up being drawn to the floating structure because it creates a source of physical cover under the pontoons.
The shorelines remained unshaded. Other species of semi-aquatic wildlife carried on foraging as normal, including freshwater turtles and North American river otters (Lontra canadensis).
Looking at the field records shows that floating solar arrays allow several species to coexist with man-made energy infrastructure in water bodies.
Microclimate dynamics and spring algae suppression mechanics
In the water, the microclimate was changed because solar radiation could not reach the surface. It was clocked by the pontoon.
The Orlando pond saw networks of sensors logging photosynthetically active radiation, the temperature of the water, and how much oxygen was dissolved in the water under the array and in the control zones without shade.
Algae blooms were activated in spring when temperatures rose. This is when phytoplankton grows fast in unshaded water. The panels had a contrasting effect because they functioned as a light shield. Light was blocked from penetrating the upper water column because of the pontoons.
The measurements of chlorophyll showed an 80 percent drop. This was in comparison to reference sites on the open water during peak bloom conditions in the spring.
Rather than preventing oxygen depletion, floating solar arrays were found to reduce dissolved oxygen levels beneath the panels, with both spot sampling and continuous monitoring showing lower average dissolved oxygen.
This included a ~0.33 mg/L drop at the Orlando site.
Control is exerted over microalgae growth with a footprint over just a small coverage area.
Urban water management complexities and the scalability of floating solar
There is a physical benefit of smaller-scale floating photovoltaics in water management in modern urban areas. The infrastructure brings a drop in green algae.
Algal blooms happen when stormwater ponds collect nutrients via surrounding streets. These degrade the quality of the algae and can also cause a bad odor.
Microalgae are dependent on light for their metabolic processes. When the water gets shaded, this process is slowed down, and it does not take chemical algaecide to do it or mechanical aeration systems that become expensive.
When the coverage area is kept at 5%, the common ecological downsides of denser solar coverage can be avoided.
Gas exchange can be restricted where air and water meet. This means lower levels of dissolved oxygen, which can be harmful to life in the water.
Targeted shade makes all the difference
It is different when it comes to small solar arrays. This is due to natural wind mixing being maintained, which means that atmospheric oxygenation can continue across the surface of the pond.
Targeted shade has the effect of cooling the water. It also reduces evaporation during the warmer seasons of the year.
The clean energy industry is seeing floating solar installations becoming more popular. By having two benefits, the system results in cleaner stormwater. Local aquatic biodiversity is protected, and urban energy goals are fostered.
All the details of the study can be found here: Cagle AE, Narwold BP, Armstrong A, Sadro S, Pasquale G, Di Blasi MLV and Hernandez RR (2025) Site-specific relationships between algal biomass and floating photovoltaic solar energy in human-made bodies of water. Front. Water 7:1614008. doi: 10.3389/frwa.2025.1614008
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