Assessing the impact of photovoltaics on rooftops and facades in the urban micro-climate

Abstract

This work addresses the potential impact of large-scale deployment of photovoltaics in the urban environment on the local micro-climate. A one-and two-dimensional steady-state irradiance balance model was developed to estimate the impact of changing the effective albedo of rooftops and facades fully covered with photovoltaic modules. Results show that, albeit small, with current PV conversion efficiencies, photovoltaics on rooftops are expected to have a heating effect on the urban environment. The effect of facades depends strongly on the reflective properties of the surroundings (e.g., road albedo) but it is always small (below 4%), and, therefore, photovoltaics ought not to be considered a mitigation strategy for urban heat island.