Ecological carbon sink gains induced by a photovoltaic power plant in the Gobi Desert

Large-scale photovoltaic (PV) power plants in arid regions not only function as renewable energy sources but can also generate ecological carbon-sink benefits by altering surface energy and water processes. This study conducted in situ observations at three PV power plants in the Gobi region of northwestern China. By integrating surface flux, soil hydrothermal, and meteorological data, we evaluated how PV installations influence vegetation growth and regional carbon-sink dynamics. Results indicate that PV arrays significantly increased surface roughness and reduced near-surface wind speed, thereby improving soil moisture conditions and enhancing accumulated temperature, jointly promoting vegetation coverage and carbon-sink formation. During the growing season, the Wujiaqu plant exhibited an additional carbon sink of approximately 236 t, with an average annual enhancement of roughly 3.37 t/MW per unit installed capacity. Preliminary cross-site comparisons suggest that PV-induced carbon-sink benefits appear to be associated with local baseline precipitation. This study elucidates the microclimatic mechanisms through which PV installations enhance carbon-sink formation in arid regions and provides direct observational evidence quantifying these carbon-sink gains.