New Study Analyzes Trade-offs of Floating Solar Energy Implementation

New Model Evaluates Floating Solar Trade-offs

Floating solar, which involves installing solar panels on bodies of water, has the potential to generate more electricity per square foot than traditional land-based solar energy. However, researchers are only beginning to grasp the implications of floating solar on biodiversity and climate. This raises important questions about how to implement this innovative technology in terms of pace, scale, and cost.

A recent study published on June 13 in *Cell Reports Sustainability* reveals that utilizing floating solar in the Northeastern U.S. could lead to significant energy gains, while also modeling potential trade-offs involving biodiversity, climate resilience, and recreational use of water bodies. The study emphasizes the need to integrate social and environmental considerations into the evaluation of renewable energy technologies.

According to Adam Gallaher, the first author and a postdoctoral researcher, “With this study, we wanted to think more holistically about the social and environmental attributes of water bodies, instead of just focusing on which ones offer the lowest-cost solar and the highest energy generation potential.” He added that the framework developed in the study could apply to other technologies, highlighting the importance of understanding how these systems interact with their surroundings and identifying potential trade-offs.

The researchers assessed the proximity of water bodies to energy infrastructure and their accessibility, finding that approximately 3.5% of existing water bodies in the Northeast are viable sites for floating solar installations. They modeled energy gains across four scenarios:

1. Utilizing all eligible water bodies.
2. Avoiding water bodies critical to climate-change resilience and biodiversity.
3. Preserving recreational use of water bodies.
4. Implementing a precautionary approach by avoiding biodiversity and recreational areas.

If all eligible water bodies were harnessed, floating solar could meet 25% of the region’s solar energy needs by 2050, effectively offsetting the land required for terrestrial solar installations. Even when conserving significant waterways for biodiversity and social use, floating solar could still provide 5% of the region’s solar energy needs, marking a 194% increase over current contributions from terrestrial solar.

Senior author Steven Grodsky, an assistant professor in the College of Agriculture and Life Sciences (CALS), noted, “Five percent may not seem substantial, but it represents a significant reduction in the reliance on terrestrial solar, translating to thousands of acres and offering a major boost to solar energy generation with minimal conflict potential.”

In New York State specifically, the study indicates that floating solar could contribute up to 55% of the required energy by 2030, decreasing to 24% when prioritizing biodiversity conservation.

This study aligns with Grodsky’s previous field research on the environmental impacts of floating solar. His recent findings show that while floating solar has lower overall emissions than terrestrial solar, it can increase greenhouse gas emissions in smaller ponds by nearly 27%. This data underscores the necessity of evaluating the trade-offs between potential energy gains and their impacts on biodiversity and climate resilience.

“Freshwater is far scarcer than land, and we must consider the socio-ecological impacts of floating photovoltaics alongside potential co-benefits such as land sparing,” Grodsky stated. He believes that acknowledging these impacts could enhance community acceptance of floating solar projects, which often face approval challenges due to public concerns.

“People are concerned about their sense of place, their views, and the effects on fish and drinking-water reservoirs,” Grodsky explained. “If these factors are overlooked during modeling and only technical viability is assessed, it could lead to misguided social responses. Incorporating comprehensive data, although more complex, provides actionable insights for informed decision-making.”

Gallaher affirmed that the study offers policymakers and stakeholders a data-driven roadmap for addressing multiple challenges effectively.

Elizabeth L. Kalies, the lead renewable energy scientist for the North America region of The Nature Conservancy, is a co-author of the study, which was supported by the Cornell Atkinson Center for Sustainability.