Small reduction in land surface albedo due to solar panel expansion worldwide

Abstract

Photovoltaic (PV) panel deployment for decarbonization may reduce local terrestrial albedo, triggering a positive radiative forcing that counteracts the desired negative radiative forcing from carbon emission reductions. Yet, this potential adverse impact remains uncertain due to limited observations at PV sites. Herein we employ a robust linear parameterization method to quantify PV-induced albedo changes based on satellite data globally. We find an overall albedo decrease of −1.28 (−1.80, −0.90) × 10−2 (median and interquartile range), specific for land-cover types and climate regimes. However, the extent of albedo reduction is markedly lower than simplistic assumed values in simulating climate feedback for solar farming in Earth system models. Moreover, the albedo-induced positive radiative forcing can be offset by negative radiative forcing from clean solar generation in most PV farms within one year. Our findings underscore PV’s potential in mitigating global warming and stress the need for more accurate model estimations. The land surface albedo reduction due to solar panel installation varies across land-cover types and climate regimes, but in most locations the decrease does not outweigh the benefits of decarbonization, according to an analysis using satellite images of 352 sites.