How Solar Farms Impact Local Water Cycles
While both traditional farms and solar farms depend on sunlight to generate energy, large-scale solar arrays can have distinct effects on the surrounding environment particularly the local water cycle.
When rainfall lands on the impermeable surfaces of photovoltaic (PV) panels, it flows differently compared to how it would on cropland, potentially influencing soil moisture, groundwater recharge, and stormwater runoff.
To address these challenges, integrating sustainable stormwater management into solar farm design has become increasingly important. As solar power continues to play a vital role in tackling climate change and promoting energy security, understanding how these facilities affect water movement is essential for long-term sustainability.
The Water Center at Penn has partnered with researchers Keith VanDerSys, Alain Plante, and graduate student Nuo Chen to study this issue. Backed by the Environmental Innovations Initiative’s PPA Renewable Energy Research Program, the team is examining stormwater runoff at AES-operated solar farms in central Pennsylvania—facilities that generate around 70% of the University of Pennsylvania’s electricity.
AES’ Great Cove Solar facility covers over 2,000 acres and produces approximately 420,000 MWh of power each year. “The scale of the PPA solar farm is striking,” said Emma Denison from the Water Center. “It was hard to picture in my mind until I stood there.” Originally farmland, the site is designed to return to agricultural use after solar operations end.
Built to meet stormwater standards, the site includes vegetated areas beneath panels, retention basins, and movable trackers that follow sunlight.
“Layers of different materials constitute these amendments; they have a crispy texture when you step on them, and precautions are in place to avoid compaction,” said Chen. AES also planted grasses and clovers to aid infiltration, while sheep graze to maintain vegetation.
“This focus on future solutions, without leaving behind ubiquitous natural resources, like water, motivates me the most about this project,” said Chen.
Photo Credit: istock-simplycreativephotography