Photovoltaic canopies: Thermodynamics to achieve a sustainable systems approach to mitigate the urban heat island hysteresis lag effect

At a time of greater attention to global climate change and increased costs of energy, our planet is rapidly urbanizing and transitioning regions from the natural rural vegetation to man-made urban engineered infrastructure. The anthropogenic-induced change has manifested itself in micro-scale and meso-scale increase in temperatures in comparison to adjacent rural regions which is known as the urban heat island effect ΔT_u-r (Oke 1987, Brazel 2003) and results in the increased need of electricity for mechanical cooling as well as various adverse environmental, social, and economic consequences for local and global communities (Golden 2004). Prior research has documented that between 29% and 45% of the urban fabric comprised paved surfaces to support mobility (Akbari et al. 1999). The increase in paved surfaces as a function of thermodynamics alters the urban energy budget due to changes in albedo, thermal mass as well as conduction, convection, and evapotranspiration. An emerging engineering option to reduce the significant role that surface pavements play in adding to the urban heat island is to capitalize on the capturing and shading of incident solar energy by means of utilization of photovoltaic panels to provide covered parking for this large portion of the urban fabric.