Floating Solar Photovoltaics: Groundbreaking New Research Reveals Promise and Complexity for Reservoirs Across the US

Floating Solar PV Research Across Multiple US Reservoirs

Researchers from Oregon State University and the U.S. Geological Survey (USGS) have pioneered a large-scale modeling effort to assess the environmental impacts of floating solar photovoltaic (FPV) systems on 11 reservoirs across six distinct states in the U.S.. This comprehensive study is the first to systematically evaluate FPV deployments in such diverse settings, covering reservoirs in Oregon, Ohio, Washington, Idaho, Tennessee, and Arkansas, while analysing two-month periods in both summer and winter for each location.

The work highlights how FPV installations offer a viable clean-energy solution, with unique opportunities to minimise land usage and enhance the co-location of solar generation with existing hydropower or pumped storage operations. Yet, the effects on the water bodies and local ecosystems are surprisingly complex and uneven, highlighting the importance of careful site selection and customised engineering approaches.

Cooling Surface Waters and Altering Reservoir Temperatures

One of the most consistent impacts measured by the OSU and USGS team was a cooling effect at the reservoir surface. Covering up to half of a reservoir with solar panels can shade and reduce solar heating, causing lower daily water temperatures at the surface layer. However, shifts in temperature do not occur uniformly throughout the entire water column. The thermal stratification, or layering of temperature with depth, can be significantly transformed based on each reservoir’s morphology, circulation patterns, and local climate.

For example, in deeper reservoirs, floating solar prompted a distinct cooling effect primarily at the upper water layer, while in shallow or wind-exposed reservoirs, the change could extend more broadly. These temperature shifts, while generally beneficial for limiting algae growth and controlling water evaporation, also have the potential to influence dissolved oxygen levels and overall aquatic habitat conditions.

Habitat Suitability for Aquatic Species: A Mixed Picture

Beyond basic temperature changes, the FPV systems were found to introduce increased variability in habitat suitability for aquatic species. Some reservoirs saw improvements for cold-water fish, while others experienced periods less suitable for target species due to changes in the timing and distribution of oxygenated and thermally optimal zones. These findings underscore that “different reservoirs are going to respond differently, based on factors like depth, circulation dynamics and the fish species that are important for management,” according to study lead author Evan Bredeweg. The ecological impact is, therefore, highly site-specific and sometimes unpredictable. While FPV can improve water quality and surface temperature in some settings, it might disrupt delicate thermal and nutrient balances in others. Responsible solar PV installers such as Atlantic Renewables can work with local water managers and regulators to anticipate these outcomes using high-quality modeling and assessment tools before construction.

Floating Solar’s Role in Reducing Water Evaporation and Enhancing Hybrid Energy Sites

Another key benefit of floating solar is its ability to limit evaporation, which is vital for reducing water loss in reservoirs—especially during drought or in arid regions. By shading large areas from direct sunlight and wind, FPV arrays help conserve stored water and mitigate the effects of climate change on local water availability.

Moreover, integrating floating solar with existing hydropower facilities enables dual use of available transmission infrastructure and backup energy supply. This hybrid approach boosts generation potential, enhances grid reliability, and can reduce overall infrastructure costs for utilities and end users alike. The UK, which faces increasing land constraints and water management challenges, could learn from this model as investment in advanced solar PV and battery storage continues to accelerate.

If you want to benefit from the latest solar technology for your own property, the team of engineers at Atlantic Renewables offers expert advice on assessing water body suitability, design, and long-term performance

The Importance of Localised Modeling and Regulatory Guidance

Study authors emphasise that “there’s no one-size-fits-all formula for designing these systems. It’s ecology—it’s messy.” Local modeling is essential: what works well in Arkansas may not yield benefits in Oregon, and vice versa. This research provides regulatory agencies and energy industry leaders with critical data for making informed decisions, setting standards, and ensuring FPV development aligns with water quality, aquatic habitat, and sustainable energy generation objectives.

Atlantic Renewables continues to work with property owners and businesses across the UK to expand solar PV and battery storage in ways that maximise environmental and financial benefits.

Floating Solar’s Future Potential and Industry Impact

The market for floating solar is well-established and growing rapidly in Asia, notably China and Japan, but remains limited in the United States and Europe. However, recent advances and the promising modeling outcomes from OSU and USGS are expected to accelerate deployment in North America. Floating solar has the potential to deliver significant clean energy while supporting local water conservation goals.

As consumer interest grows, Atlantic Renewables stands ready to design and install custom solar solutions, helping UK clients leverage new innovations from the global research frontier.

Get in Touch

To explore how floating or traditional solar PV could benefit your home or business, connect with Atlantic Renewables today. Call 0161 207 4044 to discuss if your site is a candidate for next-generation solar systems, and start taking advantage of the efficiency and cost benefits of bespoke **solar PV** and **battery storage** solutions!