Chinese researchers have found that PV arrays can reduce overall soil erosion on hillslopes while concentrating erosive forces beneath panel drip lines. The study shows that panel height, tilt angle, and layout influence runoff patterns, rill formation, and the risk of foundation scour.
A research group in China has investigated how PV installations reshape soil erosion patterns and hydrodynamic processes on hillslopes. Using simulated rainfall experiments, the researchers examined the effects of PV panel installation height, tilt angle, and array configuration on runoff and erosion dynamics.
“PV panels disrupt the natural rainfall-surface interaction through two concurrent mechanisms,” the researchers said. “They intercept rainfall over a substantial portion of the slope, reducing splash detachment and surface sealing, while simultaneously concentrating intercepted water along panel lower edges as high-energy drip flow. This redistribution creates a distinctive spatial pattern in which covered zones receive no direct rainfall while drip lines receive concentrated flow with substantially enhanced erosive energy.”
The researchers conducted rainfall simulation experiments using a 2.0 m × 1.0 m × 0.4 m adjustable soil flume. They filled the flume with clay-loam agricultural soil collected from the southern Loess Plateau in China and set it at a fixed 10-degree slope. Four custom-made PV modules, each measuring 57 cm × 48 cm, were installed above the soil in either a linear (1 × 4) or block (2 × 2) configuration.
