A building energy demand and urban land surface model

Abstract

Cities are unique environments where anthropogenic waste heat from energy consumption changes the dynamics of the boundary layer, affecting temperatures, pollution dispersion and buoyancy-driven flows. Although urban environments are important for societal wellbeing, there are relatively few models that link predictions of waste heat variability with urban climate interactions. This study presents the Urban Climate and Energy Model (UCLEM): a new physically based model representing important heat transfer processes between the atmosphere, external and internal urban environments, combined with a statistical model of human behaviours relating to energy use. The aim of UCLEM is to efficiently predict the climatology of different urban areas, as well as the energy used to maintain comfortable temperatures within buildings. The model is designed to be easily adaptable to a wide range of urban settings with adjustable parameters including building height, density, material thermal and radiative characteristics and vegetation fractions. We assess UCLEM's ability to predict energy consumption for a neighbourhood of Melbourne, Australia, forced by local flux tower observations and evaluated at half-hourly intervals over 12 months. Results are presented in four development stages to assess various levels of physical and behavioural model complexity. We show that more complete physical representations can improve average daily energy consumption predictions; however, sub-daily patterns of energy use are improved only by combining the physics-based model with a statistical model of human behaviour. At the final stage, as well as predicting surface-atmosphere radiant and turbulent fluxes, UCLEM estimates neighbourhood energy demand with a normalised mean error of 11.5% and a computation time on a single processor of about 1 s per simulation year. KEYWORDS anthropogenic waste heat, building energy demand, urban meteorology 1 Q J R Meteorol Soc. 2018;144:1572-1590.wileyonlinelibrary.com/journal/qj

How an urban parameterization affects a high‐resolution global climate simulation

“…Because cities around the globe have widely differing structures, forms, fabrics and energy emissions (as noted by Jackson et al ., 2010), their heterogenic characteristics must be considered in urban parameterizations. Improvements to UCLEM by including spatially varying urban parameters along with industrial heat and diurnally and seasonally varying building heating (as has been done by Lipson et al ., 2018) will allow for an even more realistic presentation of urban areas in climate models. Future changes in urban areas (particularly related to urban growth scenarios) along with future changes in land cover should also be included in the model simulations.…”

Climate change impact on energy demand in building-urban-atmosphere simulations through the 21st century

“…Statistically-based studies, or those that use uncoupled warming projections to drive building energy models (BEMs), do not capture interrelated climate-energy feedbacks across all relevant scales. In order to capture these feedbacks, previous studies have integrated BEMs within urban canopy models (UCMs) to simulate urban-atmosphere energy and momentum flux exchange in numerical weather simulations (Kikegawa et al 2003, Salamanca et al 2009, Bueno et al 2012, Mauree et al 2017, Lipson et al 2018. Dynamically downscaling GCMs to regional and local scales and then coupling with an integrated BEM and urban canopy model in three-dimensional (3D) simulations will capture these feedbacks, but the approach is computationally expensive, limiting the range of climate variability and the variety of scenarios that can be sampled (Ortiz et al 2018).…”

“…The near-surface environment is simulated by the Urban Climate and Energy Model (UCLEM) (Lipson et al 2018), an extension of the Australian Town Energy Budget (ATEB) urban canopy model (Thatcher and Hurley 2012). ATEB and UCLEM were developed to represent Australian cities in regional weather and climate simulations.…”

“…ATEB and UCLEM were developed to represent Australian cities in regional weather and climate simulations. Together they are capable of predicting realistic air temperatures and winds (Thatcher and Hurley 2012), radiant and turbulent fluxes (Lipson et al 2017), and building energy demand variability (Lipson et al 2018). Since Lipson et al (2018), a number of model developments have further improved energy demand predictions when driven by local meteorology, and allowed the partitioning of electricity and gas demand separately (described in supplementary material is available online at stacks.…”

“…Electricity and gas demand (2000-2009) from state-level observations, scaled by population to energy use intensity in suburban Melbourne, Australia. SeeLipson et al (2018).…”