Large, ground-mounted photovoltaic solar farms (GPVs) are expanding worldwide to support climate change mitigation and the transition towards a low-carbon economy. Few studies have explored the ecological impacts of tracking GPVs and maintenance activities for utility-scale operations on microclimate and vegetation patterns. Here, we explored the ecological impacts of a single-axis, tracking GPV and regular mowing in the Great Central Valley of California, United States. First, we developed an experimental framework of five unique “micro-patches” that characterize the heterogeneity of the dynamic microclimate and vegetation zones created by a single-axis, tracking GPV. Across these five micro-patch types, we evaluated nine above- and below-ground microclimate variables and 16 vegetation properties. We found that the micro-patches under PV panels reduced photosynthetic active radiation and wind speed by 90% and 46%, respectively, compared to open spaces along the facility perimeter. In contrast, soil surfaces in the open spaces were warmer and experienced faster soil moisture loss than micro-patches near or within array footprints during drought seasons. We found no significant difference in air temperature, relative humidity, and vapor pressure deficit across all micro-patches daily. We identified 37 plant species, of which 86% were exotic. Fully exposed to higher incoming solar radiation, plant communities in the open spaces experienced senescence the earliest compared to other micro-patches. We discuss the implications of our results for managing single-axis, tracking GPVs, particularly activities seeking to achieve enhanced control of the noxious weeds and other ecologically beneficial outcomes.

Floating photovoltaic solar energy (FPV) are solar photovoltaic systems that float on bodies of water. They are a rapidly expanding renewable energy source emerging as an alternative to land-intensive ground-mounted solar arrays. The applications of this technology are commonly explored through technical potential assessments; a vital step in the development of renewable energy resources that allow for the identification of feasible installation sites and provide an estimation of costs, power generation, and capacity (Lee and Roberts 2018). These assessments are carried out to aid planners, policymakers, and other decision-makers in predicting and achieving goals related to the development of renewable energy; however, some considerations may be overlooked. Assessing the technical potential of solar energy without a standardized methodological framework for site selection may lead to an inconsistent range of generation outcomes, adding to the confusion and lack of confidence that has been a significant barrier to the growth of renewable energy in recent years (Seetharaman 2019) This study systematically reviewed criteria in the published literature emphasizing assessment of FPV technical potential and related siting studies, especially those using geographic technologies. The systematic review was performed in alignment with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Preliminary findings of this systematic review suggest that FPV site selection criteria can be categorized into economic, social, environmental, and technical considerations. We aim to elucidate which criteria within each classification are important to include in an FPV siting study based on the current literature. Results from this analysis will inform the standardization of a site-selection framework used in future technical potential studies, which may, in turn, improve the accuracy of generation estimates and offer a meaningful and realistic idea of how FPV installations could transform the direction of renewable energy science and development.