Estimating the building based energy consumption as an anthropogenic contribution to urban heat islands

Today the implication of buildings’ electricity demand on the outdoor climate around buildings is not fully understood. For tropical cities like Singapore, where air-conditioning is required throughout the year and high rise buildings irregularly alternate with lower buildings, the distribution of this so called anthropogenic heat emissions in time and space is determining the local and overall contribution to the urban heat island (UHI). In the absence of detailed measurements calculating the local consumption can be challenging. We present a methodology which combines a top-down disaggregation of sectoral electricity consumption with a bottom-up geographic information system (GIS) derived building database for obtaining anthropogenic heat emission maps with high spatial resolution. The database has been validated through control samples. Using the example of Singapore we can show that heat emissions are more inhomogeneous and higher in magnitude than previously estimated. Our method can now be employed to generate better UHI models by identifying areas with significant anthropogenic heat emissions.