The guide for stormwater best practices for solar farms developed for the groundbreaking Photovoltaic Stormwater Management Research and Testing (PV-SMaRT) project is now available. The best practices provide guidelines to communities, developers, and state and federal regulators on how solar development should be evaluated under the Clean Water Act. This guidance can resolve many uncertainties in the permitting process regarding stormwater management and surface water quality.
Best practices based on groundbreaking research on solar and water quality
The Great Plains Institute helped lead the PV-SMaRT project along with the National Renewable Energy Laboratory, Fresh Energy, and the University of Minnesota. PV-SMaRT was funded by the US Department of Energy’s Solar Energy Technologies office. The goal of the PV-SMaRT project was to develop and disseminate research-based, photovoltaic (PV)-specific tools and best practices for stormwater management and water quality at ground-mounted PV sites.
As shared in the press release of the PV-SMaRT findings, this was the “first scientific study to detail and document the unique characteristics of solar development that affect water quality.”
Five sites across the country—representing a wide range of elevations, slopes, soil types, and geographical locations—were used to study stormwater infiltration and runoff. As a result of the research and hydrological modeling conducted, GPI developed the guide for best practices on water quality for solar farms.
Guide provides best practices for protecting and even enhancing water quality at solar farms
Brian Ross, vice president of Renewable Energy at the Great Plains Institute, states, “The scientific research and modeling showed that stormwater conventions in permitting did not consider the unique characteristics of solar as a land use. We developed the best practice guide to help developers and regulators understand what they needed to be looking at to best protect and potentially even enhance water quality for communities hosting solar farms.”
One of the important findings of the PV-SMaRT project is that, when following the guide’s best practices, solar farms can significantly reduce local water quality impacts compared to most agriculture forms, potentially restoring watershed functions and improving impaired waters.
The best practice guide accompanies an easy-to-use solar runoff calculator developed by the University of Minnesota. The calculator condenses the modeling into a user-friendly spreadsheet for estimating stormwater runoff or developing stormwater “curve numbers” for incorporation into site-specific modeling.
More about this groundbreaking project can be found on the National Renewable Energy Laboratory’s website.
