Capturing available solar energy on urban-scale building surface: A multi-dimensional perspective

Abstract

The available solar energy on urban building surfaces is essential for the energy transformation. Many cities have installed building photovoltaic, but it has not fully exploited the potential of the building surface. Based on geographic information and open-source meteorological data, the methodology employs the Radiance simulation engine to generate multi-condition sky luminance distribution matrices. Through spatial partitioning of the buildings into thousands of clusters based on Area of Interest, the analysis evaluates shading impacts at building level. The calculation results deconstruct the complex solar radiation condition on urban-scale buildings from a multi-dimensional perspective (space, time, solar radiation types) to maximize solar energy utilization. The findings indicate that: (1) Building surfaces in Hangzhou capture 1.74 × 10¹¹ kWh of global solar radiation each year, with roofs and facades accounting for 54 % and 46 %. The roof and southern facades offer excellent opportunities for solar energy utilization. (2) 1.41 × 10¹¹ kWh of global solar radiation each year meets the usage criteria with a direct-to-diffuse ratio of 0.8. The solar power potential of building surfaces is estimated at 1.99 × 10¹⁰ kWh, which fulfill 28 % of the city’s annual electricity demand, with greater generation capacity during summer. (3) The levelized cost of electricity of different plans demonstrate that prioritizing rooftop photovoltaic deployment yields optimal economic returns, followed by southern facades. Leveraging the technical and economic potential, it is recommended that policymakers continue rooftop photovoltaic development, advance southern photovoltaic, explore pilot projects for eastern and western photovoltaic. The study provides actionable strategies to further exploit photovoltaic potential, evidencing solar energy’s crucial role in facilitating urban energy transitions and advancing sustainable development goals.