Assessment of photovoltaic power generation and radiative cooling potentials in old residential districts: A case study of Shenzhen

Abstract

Building-integrated photovoltaic (PV) and radiative cooling (RC) are promising technologies for attaining the zero-carbon target in building industry. The PV and RC materials can be utilized for energy-saving renovations in building envelopes of existing residential districts. Nowadays, it is common practice to add thermal insulation to old residential districts to reduce building energy consumption. Whereas the development of PV and RC technologies provide opportunities of renewable energy utilization on building envelops in old residential districts renovation. The space for installing PV and RC materials on the roofs and facades is restricted. Hence, assessing and contrasting the efficacy of PV and RC materials in different sections of building envelopes is important from both energy and economic aspects consideration.This study employed the Rhino-Grasshopper platform to assess the energy and economic performances of PV and RC technologies when installed on roofs and facades with varying orientations. A typical old residential district in Shenzhen was employed as an example. The objective was to enhance the allocation of PV and RC components to attain optimal energy and economic outcomes. The life-cycle equivalent energy saving was used as economic indicator. Results demonstrated that PV is more suitable on roofs application, whereas RC is more suitable for facades. It is profitable to apply RC on the north facade whereas PV can be profitable when applied to the other envelops. By applying PV and RC to all old residential districts in Shenzhen, the annual PV power generation and cooling energy saving from RC are as high as 5299 GWh and 277 GWh. This study demonstrated that PV and RC are promising technologies in energy-saving renovation of old residential districts. The developed methodology can be applied in renovation projects to achieve optimized designs.