Scaling solar in dense cities: The availability and affordability of distributed photovoltaics (DSPV) electricity in Shenzhen

The availability and affordability of renewable energy are crucial for energy transition. This study develops a geospatial–techno-economic framework to evaluate DSPV potential and costs across Shenzhen's scattered, irregular, and diverse (SID) spaces, focusing on rooftops, building façades, and road noise barriers. Leveraging building vectors with height attributes, a shadow analysis model and solar ray-tracing algorithms were employed to quantify the effects of mutual shading and surface inclination that significantly compromise the capacity factors of PV. High-resolution irradiation data, meteorological parameters, and an irradiation model were utilized. The levelized cost of electricity (LCOE) is analyzed based on installation costs, operational expenses, and other market-driven parameters. The results reveal that rooftops, building facades, and RNBs' PV electricity generation potentials are 21,165 GWh/year, 85,131 GWh/year, and 5.43 GWh/year, respectively, almost equivalent to 94% of Shenzhen's annual electricity demand in 2023. Affordability is a much bigger concern with their LCOE ranges being 0.020–0.421 USD/kWh, 0.058–0.261 USD/kWh, and 0.090–1.404 USD/kWh under different scenarios, respectively. These findings illustrate that spatial constraints in dense cities not only affect the availability of solar electricity but also, more importantly, its affordability.