| Work Detail |
A series of longitudinal studies of three Minnesota solar farms have shown that native species grow beneath solar panels, providing soil benefits and habitat for wildlife and pollinators.
Research led by the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) has collected data on the interactions among habitat, pollinators, soil, and solar energy production at three utility-scale solar projects in Minnesota.
NREL’s InSPIRE (Innovative Solar Practices Integrated with Rural Economies and Ecosystems) team has been conducting research at all three sites for the past six years, in what the lab says is the longest and most comprehensive assessment of solar, soil, habitat and pollinator interactions to date.
The results are presented in three studies: “ Environmental Co-Benefits of Maintaining Native VegetationWith Solar Photovoltaic Infrastructure” available at Earth’s Future , “ If you build it, will they come? Insect community responses to habitat establishment at solar energy facilities in Minnesota, USA” available at Environmental Research Letters , and “ Little prairie under the panel: testing native pollinator habitat seed mix establishment at three utility-scale solar sites in Minnesota” available at Environmental Research Communications .
The three solar facilities studied in the papers are Chisago, Atwater and Eastwood, part of the Aurora solar project owned by Enel Green Power and located in and around the Minneapolis area. NREL says these solar-pollinator sites are the first commercial-scale solar projects in the U.S. to have extensive research into ecovoltaics.
The research found that prairie restoration activities can take place beneath solar panels. Once prairie vegetation was established, pollinators were found to use the site as much as dedicated conservation lands, with evidence pointing to increased abundance and diversity of both vegetation and pollinators beneath the solar panels.
The grassland vegetation took three to four years to fully establish itself after the solar park was built, with some species not appearing until five to six years later.
The research adds that planting pollinator habitats and native vegetation mitigates some of the environmental damage done to soil and habitat when solar facilities are built and may protect soil from future erosion, but it also warns that it can take a long time to restore soil after damage caused by intensive corn and soybean production. NREL says the overall impact of soil restoration activities in these locations will not be clear for several years.
Researchers also observed little to no impact on annual electricity generation across all sites. While native habitats were found to reduce the temperature of PV modules compared to the underlying soil, this was not found to increase electricity production.
NREL says this finding contradicts studies in other regions, which suggest that the microclimatic interaction between photovoltaic panels, soil and vegetation is not consistent across different landscapes and climates. “One of the most important takeaways from this research is that we need to study more locations,” says Chong Seok Choi, an agrivoltaics researcher at NREL. “For example, the specific climate of the location — how much humidity there is in the air, for example — may affect whether the cooling we see in the native habitat can lead to increased photovoltaic efficiency. There is still a lot of work to be done.”
All three studies were funded by the U.S. Department of Energys Solar Energy Technologies Office and conducted by NREL and Argonne National Laboratory, along with research partners from the University of Minnesota and Temple University and practitioners from MNL, formerly Minnesota Native Landscapes. |
