Renewable energy projects are booming across the country. As solar energy becomes an increasingly popular alternative to fossil fuels, clean energy organizations are examining how best to support solar projects and the host communities in which they are built to protect local water quality and habitat. 

"Most existing water quality standards and best practices were not designed or tested for solar installations," says Brian Ross, vice president at Great Plains Institute, "largely because there is a lack of science-based data connecting solar array development to long-term land use issues, like the effect they have on surface and ground waters. While these are interim results, they are very encouraging, and we look forward to validating them in the coming year." 

The Photovoltaic Stormwater Management Research and Testing (PV-SMaRT) project aims to address this critical gap in water quality and cost management practices at solar installation sites, often called solar farms, across the United States. The project developed science-based standards for estimating local water quality impacts of solar developments, and assessed possible new permitting practices and standards for solar development. 

Because the United States solar industry first took off in the desert Southwest, a standard practice for the land on solar sites is gravel and/or monocrop lawn grass. That changed in 2016 when Fresh Energy and partners worked with agricultural and business leaders to establish the nation's first statewide standard for vegetation on solar sites. Since then, demand for deeper research on solar site vegetation and water management has grown. 

With projects like PV-SMaRT, Great Plains Institute, Fresh Energy, the University of Minnesota, and the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL) are part of a broader movement to encourage solar development that enhances eco-system services and provides local co-benefits; using deep-rooted native flowers and grasses that capture and filter storm water, improving impaired rivers and lakes, building topsoil and restoring soil health, and creating abundant and healthy food for pollinators that provide critical services to our food and agricultural systems. 

"The end goal is to develop research driven tools and best practices that can be used by permitting authorities and [photovoltaic solar (PV)] developers to make more informed decisions on stormwater management measures that are tailored to the true impacts of a PV array on the environment," says Jennifer Daw, principal investigator for the PV-SMaRT project and Group Manager at NREL. 

Stormwater permitting standards based on these best management practices will lower the costs of clean energy development and ensure protection of the host community's surface and ground waters. With more solar development on the horizon, these new tools will help craft a sustainable clean energy future that will benefit all. Experts and stakeholders will continue to reconvene in this process throughout 2022 to both validate and provide feedback on this foundational research.  

The PV-SMaRT project is funded by DOE's Solar Energy Technologies Office and led by NREL in partnership with Great Plains Institute, the University of Minnesota, and Fresh Energy. PV-SMaRT received extra support from a National Water Quality Taskforce comprised of 13 other organizations who helped direct the project's science-based standards for estimating local water quality impacts of solar developments, and more. 

Fresh Energy | www.fresh-energy.org

Great Plains Institute | www.betterenergy.org