In the sprawling landscapes of California’s Great Central Valley, a silent revolution is underway. Ground-mounted photovoltaic solar projects (GPVs) are proliferating, driven by the urgent need to mitigate climate change and transition to a low-carbon economy. Yet, as these solar farms expand, so do the questions about their ecological impacts, particularly those stemming from their operation and management (O&M). A recent study led by Yudi Li of the Wild Energy Center at the University of California, Davis, sheds new light on these issues, revealing how single-axis tracking solar systems influence microclimate and vegetation patterns.
Li and his team developed a novel experimental framework to examine the ecological impacts of GPVs, focusing on five distinct micro-patches within a solar farm. These micro-patches capture the full spectrum of microclimate and vegetation zones modulated by the tracking PV system and O&M practices, such as regular mowing. Over a year, the researchers monitored nine above- and belowground microclimate variables and 16 plant ecology metrics across these micro-patches.
The findings are striking. Beneath the PV panels, photosynthetically active radiation decreased by a staggering 89%, and wind speed slowed by 46%. In open spaces within the GPV footprint, soil surface temperatures rose by 2.4°C, and moisture loss accelerated by 8.5% during drought periods. “These changes in microclimate can significantly alter the local ecosystem,” Li explains. “The shading and reduced wind speed beneath the panels create a unique environment that favors certain plant species over others.”
The study identified 37 plant species, with 86% being non-native. The vegetation near and within the PV array footprint showed greater species richness, taller maximum height, reduced coverage of sun-loving plants, and less dead biomass accumulation. These changes highlight the complex interplay between solar panel shading, plant community composition, and ecosystem productivity.
The implications for the energy sector are profound. As the global market for tracking systems is projected to increase annually by 32% in capacity by 2050, understanding and mitigating these ecological impacts will be crucial. Li suggests that micro-patch-specific maintenance strategies and nature-based solutions could control invasive, exotic plant species, enhancing operational, ecological, and socioeconomic sustainability.
“This research underscores the need for a holistic approach to solar farm management,” Li says. “By understanding the microclimate and vegetation dynamics, we can develop strategies that not only enhance solar energy production but also promote biodiversity and ecosystem health.”
The study, published in Frontiers in Sustainability, offers a roadmap for the future of solar energy development. As the world races to adopt renewable energy sources, it is essential to balance the need for clean energy with the preservation of our natural ecosystems. Li’s work provides a critical step forward in achieving this balance, offering insights that could shape the design and management of future solar projects.
