What drives residential rooftop solar growth in China? A spatial analysis using city-level data

Abstract

The growth of Residential rooftop solar (RRS) in some western countries has predominantly been driven by individual or market behaviour and has been extensively studied. However, the development landscape of RRS in China differs, and its driving mechanisms remain unclear. To address this research gap, we investigate the spatial distribution pattern and driving factors of RRS growth using city-level data on RRS installation. Employing the Geographical Detector Model, we calculate indicators to identify the contributions of various socio-economic factors to RRS growth and the strength of their interactions. Our key findings include: 1) significant spatial heterogeneity in RRS growth across regions with different natural and socio-economic characteristics, which impact RRS growth in two patterns: one-way and inverted U-shaped; 2) although solar radiation abundancy is important, air pollution and certain socio-economic factors appear more influential, be it comparing between the eastern and western China, or north and south; 3) the significance of fiscal subsidies has diminished, but benchmark electricity prices (BEP) could serve as a useful alternative; 4) substantial synergistic effects exist between different factors, with environmental and demographic factors displaying particularly strong synergies with others, suggesting that they are essential considerations for future RRS planning. Our findings contribute to a comprehensive understanding of RRS development in China and hold critical implications for future policy design.