Improvement of WRF–CM–BEM and its application to high-resolution hindcasting of summertime urban electricity consumption
Ko Nakajima, Yuya Takane, Yukihiro Kikegawa, Kazuki Yamaguchi
Abstract
This study validated the electricity consumption (EC) simulated by a regional climate model coupled with an urban canopy model and building energy model (WRF–CM–BEM) to improve the model’s reproducibility of spatiotemporal variation in EC. We first used observed EC data covering the entire study area of the Tokyo Metropolitan Area with a horizontal resolution similar to model grids (a few square kilometres). To improve the reproducibility of the horizontal distribution of EC and the sensitivity of EC to outdoor air temperature (ΔEC/ΔT), the following three parameters were newly considered in the model. First, the heat from appliances inside buildings was considered for each grid. Second, the temperature-dependent, working air-conditioning (AC) ratio, which is the hourly ratio of actual floor area air-conditioned with AC systems in buildings, was considered. Finally, the share of electricity (gas)-driven AC systems was set for each grid. The improved model case (CASENEW) enhanced the reproducibility of both the horizontal distribution of EC and ΔEC/ΔT. CASENEW reproduced the summertime EC, with normalised mean absolute errors of 4.96%, 9.61%, and 8.95% in typical office, fireproof apartment, and wooden detached dwelling areas, respectively. These reproducibility values of CASENEW are better than those of previous studies. The improved WRF–CM–BEM will help the projection of present and future EC and thermal environments in urban areas. They will also facilitate the assessment of the potential of global warming mitigation (adaptation) strategies toward urban energy conservation.