Parametric design of urban forms and building-integrated two-stage solar concentrators (TSSCs) to assess solar potential, daylight, and energy balance in various climates

This study proposes a method to facilitate an integrative design of urban typologies and roof-integrated two-stage solar concentrators (TSSCs) as energy supply solutions in 14 locations. This is achieved through a parametric model by manipulating urban typology (form factor, block height, orientation, roof shape, and slope) and TSSC geometry (type, geometric ratio, focal length-to-diameter ratio, and modules area). A large design space (8400 options) is evaluated for annual energy balance in terms of energy use (EUse) and average load match index (av.LMI); solar potential in terms of direct normal irradiance (DNI), and daylight performance in terms of useful daylight illuminance (UDI(100–2000 lx)) and continuous daylight autonomy (cDA(500 lx)). The method is validated in illustrative cases of urban typologies with three stories (low-rise) to six stories (mid-rise) residential buildings, as abstract representations of future constructions in different Köppen-Geiger climate-groups. In tropical and arid climates, most designs achieve high cDA(500 lx) (>50 %) and UDI(100–2000 lx) (>80 %). In these climates and temperate climates, designs show medium EUse (1000–3000 MWh). Most designs show medium DNI (50–100 MWh) except in Berlin and Bucharest, and low av.LMI (<0.5) except in Miami, Brasilia and Shanghai. Filtered designs show low EUse (<1000 MWh) and high av.LMI (>1) in all, high DNI (>130 MWh) in Brasilia and Shanghai, and high cDA(500 lx) and UDI(100–2000 lx) in tropical and arid climates. The method thus enables early-stage design exploration of urban areas employing TSSCs in multiple locations and serves as a guiding framework to design sustainable cities harnessing solar energy, and implement energy transition policies globally.