Modeling impacts of roof reflectivity,integrated photovoltaic panels and green roof systems on sensible heat flux into the urban environment

This study presents results of a modeling effort to explore the role that sustainable roofing technologies play in impacting the rooftop energy balance, and the resultant net sensible heat flux into the urban atmosphere with a focus on the summertime urban heat island. The model has been validated using data from a field experiment conducted in Portland Oregon. Roofing technologies explored include control dark membrane roof, a highly reflective (cool) roof, a vegetated green roof, and photovoltaic (PV) panels elevated above various base roofs. Energy balance models were developed, validated with experimental measurements, and then used to estimate sensible fluxes in cities located in six climate zones across the US.