PS 63-6 - Long-term ecological implications of solar arrays: A preliminary study on fallowed farmland and proposal for citizen science applications

Friday, August 11, 2017
Exhibit Hall, Oregon Convention Center
Josia DeChiara, Rachel Rosenberg and Seeta Sistla, Natural Science, Hampshire College, Amherst, MA

As the global atmospheric carbon dioxide (CO2) level has already surpassed 400 ppm, renewable energy (RE) generation in the 21st century is in the forefront of current environmental policy decisions. While research into energy generation technologies and life-cycle analyses has been extensive, there is little understanding of land-use optimization and ecological interactions. Solar energy is the fastest growing RE technology globally, yet the interactions of photovoltaic (PV) arrays on surface microclimate, biodiversity, and plant-soil interactions have been marginally studied. The heterogenous shading and precipitation patterns introduced by PV arrays may impact abiotic conditions for soil, plant, and fauna communities in a novel manner. Given the rapidly increasing land-use transition to PV arrays, changes in biodiversity and biogeochemical cycling may have notable impacts when scaled up over hectares and decades, making these interactions pertinent to future policy and siting decisions.


A preliminary study of three PV arrays (>1 MW) on fallowed farmland in southern VT quantified the effect of panel presence and seasonality on microclimatic factors, soil properties, plant and invertebrate communities. We found significant panel effects on soil temperature, moisture, and organic matter content; and plant community composition, moisture, biomass, and stoichiometry. Significant but site-specific effects on soil decomposer extracellular enzymatic activities and invertebrate communities were found.

This framework will be utilized in a long-term study at Hampshire College (Amherst, MA), where 19 acres of conventionally managed corn fields have been converted into PV arrays and will be seeded with a “pollinator-friendly” plant mix to promote synergistic interactions between energy generation and ecosystem services through the generation of critical pollinator-friendly habitat. The impacts of the first summer of this array deployment on biotic and abiotic factors will be presented. Additionally, using methods we have compiled into a publicly accessible research manual, we propose increasing a citizen-science component of RE research, particularly as PV arrays appear on more public spaces and across varied landscapes.