Decreased wind erosion at a solar energy facility with low-impact compared to conventional construction

Abstract

Wind erosion and dust emission can diminish air quality, harm human health, and impact ecosystems and agriculture. Dust can also interfere with operations of solar energy facilities, reducing energy output and damaging infrastructure. To better understand the patterns and drivers of wind erosion in solar facilities, we measured airborne sediment flux in passive dust samplers for 20 months through the construction and early operation phases of two utility-scale photovoltaic solar energy facilities in the Mojave Desert. One facility was constructed using typical methods of blading vegetation and grading soil (“blade and grade”), while construction at a second facility left soils and vegetation more intact by passing over them with vehicles as needed (“overland travel”). We expected more intact vegetation and soils to protect against wind erosion, but this hypothesis has not been tested in solar facilities. We found that wind erosion in the blade and grade facility was over 200 times higher than an undisturbed control area, while the overland travel facility had sediment flux 5 - 10 times higher than controls depending on soil texture. Across all monitoring sites, elevated wind erosion was best explained by low forb cover, low soil aggregate stability, and high soil compaction; the latter serving as a broad indicator of disturbance. Forb cover in many areas was dominated by non-native species, illustrating a trade-off between removing non-natives and preserving soil protection from erosion. Our results demonstrate that low impact construction methods can protect soils from wind erosion, minimizing fugitive dust from solar energy development.