A Methodology for Buildings Access to Solar Radiation in Sustainable Cities

Abstract

The growing need to improve the environmental and energy sustainability of buildings involves the use of solar radiation incident on their surfaces. However, in cities, this task is complicated due to the constructive geometry that leads to shading between buildings. In this context, this work presents a study of solar access to the façades of buildings in cities. The methodology is based on the determination of the incident annual solar radiation in 121 significant points of each façade considering the twelve representative days of the year. To characterize the influence of the different city typologies on solar access, the urban solar coefficient is proposed. A study of two neighborhoods in Cordoba (Spain) with different urban settings have been analyzed. Specifically, two typologies of neighborhoods have been compared: one with “L-shaped” and “U-shaped blocks” and another with “Grouped blocks”. For both of them, the Urban Solar Coefficient has been calculated, obtaining a higher mean value for the neighborhood with “L-shaped” and “U-shaped blocks” (0.317) than for the one with “Grouped blocks” (0.260). Accordingly, the results show that urban morphology can influence the Urban Solar Coefficient and solar access. Finally, a regression model for each neighborhood has been obtained in order to determine the dependence of the Urban Solar Coefficient on neighborhood geometry factors.

Characterization of an experimental agrivoltaic installation located in a educational centre for farmers in Cordoba (Spain).

“…Fig. 6 shows these solar irradiance maps on the crop obtained by means of the mathematical models based on the methology proposed by Fernández-Ahumada et al [16] I). From this table it can be deduced that the expected average production for the year is 11,980 kWh/year.…”

“…Since radiation levels can affect crop production, the results of the phenological study will be analysed according to the position and degree of shading of each plant. For that purpose, solar irradiance maps on the crop land have been obtained by applying mathematical models based on those proposed by Fernández-Ahumada et al [16] for estimating incident solar irradiance on surfaces in environments with obstructions. Specifically, these models take into account all the components of solar irradiance (direct, diffuse and reflected) as well as the percentage of the celestial vault free of obstructions that is perceived from each point.…”

Simulation of Self-Consumption Photovoltaic Installations: Profitability Thresholds

“…Also noteworthy is the relationship between urban morphology, the Sky View Factor or tree shadows and the potential of renewable energies [28][29][30]. Together with the different orientations of the panels, the detailed study of the unobstructed accessibility of the buildings of a city to the solar resource is proposed as a differentiating fact in the design of urban developments [31,32].…”