By Blake Jackson
Both traditional farms and solar farms harness sunlight to generate energy, but utility-scale solar arrays can influence the local water cycle in unique ways.
When rain falls on the impermeable surfaces of photovoltaic (PV) panels, it drains differently than on croplands, potentially affecting soil moisture, runoff, and groundwater recharge.
However, integrating sustainable stormwater management into solar farm design can help offset these effects. Since converting sunlight to electricity is vital for combating climate change and ensuring energy security, studying stormwater runoff from solar farms is key to a sustainable energy future.
To explore this issue, the Water Center at Penn has partnered with Keith VanDerSys, Alain Plante, and graduate student Nuo Chen. Supported by the Environmental Innovations Initiative’s PPA Renewable Energy Research Program, their team is examining stormwater runoff at AES-operated solar energy sites in central Pennsylvania, which provide about 70% of Penn’s electricity.
AES’ Great Cove Solar facility spans over 2,000 acres and produces roughly 420,000 MWh annually. “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.” Once farmland, the site aims to return to agricultural use after decades of solar production.
Built to meet county stormwater standards, the site features a vegetated landscape beneath the panels, rain basins near substations, and movable trackers that follow sunlight. AES also used soil amendments to improve infiltration and reduce flooding.
“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.
To support infiltration and attract pollinators, AES planted grasses and clovers, while sheep graze on-site to maintain vegetation and benefit local farmers.
The Penn team is now developing a stormwater monitoring framework using meteorological and hydrological data. “Using a hydrological model will allow us to map and predict runoff and infiltration rates for various rainfall scenarios,” said Chen.
“This focus on future solutions, without leaving behind ubiquitous natural resources, like water, motivates me the most about this project.”
Photo Credit: istock-simplycreativephotography
Categories: Pennsylvania, Education, Energy