Examining How White Roof and Solar Panel Solutions Contribute to Urban Heat Island Mitigation; A case study in Worcester, Massachusetts

Keywords: Worcester, Urban Heat Island, Land Surface Temperature, White Roof, Solar Panels, Cooling, Local Climate Zones, Urban Functional Zones
Session Type: Virtual Poster Abstract
Day: Friday
Session Start / End Time: 2/25/2022 05:20 PM (Eastern Time (US & Canada)) - 2/25/2022 06:40 PM (Eastern Time (US & Canada))
Room: Virtual 40

Abstract

The Urban Heat Island phenomenon (UHI) is a growing concern due to the compounding effects of urban densification and regional climate change, in the form of extreme summer temperatures and flash flooding events. Various types of green infrastructure are promoted to mitigate UHI and reduce flooding. Yet for city planners modifying existing grey infrastructure may be the more accessible option due to issues with available space. Two popular green infrastructure options involve painting roofs white to increase albedo and installing photovoltaic panels to reduce building energy demand and decrease utility costs. This study will investigate how white roof treatment and solar panel installation have impacted land surface temperature (LST) in Worcester, Massachusetts between 2013 and 2021 using Landsat-8 thermal imagery (10.60 - 11.19 µm). The normalized z-score values of the Landsat imagery can demonstrate the variation in rooftop temperature before and after treatment. The local climate zone generator was used to produce local climate zones, based on the type of built and green infrastructure present. Urban functional zones were additionally determined by land use and land cover data. Both variables, including building height—acquired through LIDAR—were evaluated within the random forest model to determine which variable has the greatest impact on LST. Results show a cooling of 1 degree Fahrenheit in LST for every 0.411 acres of roof treated. Therefore, we hypothesize that cooling potential can be maximized by determining the effect of buildings with treated roofs and urban morphology on the surrounding urban heat island.