Potential increase of solar irradiation and its influence on PV facades inside an urban canyon by increasing the ground-albedo

摘要

Due to the large demand for electricity in cities, photovoltaic (PV) installations inside the urban environment will increase in the near future. It is known that the yield of PV systems on facades can be increased by increasing the ground-albedo. White surfaces are also proposed for urban heat island mitigation. Thus, increasing the ground-albedo inside the urban environment has multiple advantages. However, solar potential simulation tools are not yet designed for simulating in an urban canyon. The ground-reflected irradiance is either neglected or the known approximation is applied. The potential contribution of ground-reflected irradiance to the electricity production of PV facades in an urban canyon is not yet investigated. Therefore, measurements were made in a street canyon to show the potential effect of an increased ground-albedo on the power output of south-facing, vertically mounted PV modules and the total in-plane irradiance. Further, the potential increase of PV yield on a reference point was estimated, when asphalt on an approximately 15 m wide street canyon was replaced with a highly reflective concrete and an albedo of 0.5. For the latter case, at a wall point 12 m above ground and with a ground view factor of 0.16, it was found that during an eleven days reference period in August 2016, in Vienna, the PV yield increases by 7.3%.