Energy
Climate change mitigation, Smart city

Energy demand modeling and decarbonization of residential
and commercial building stock
Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering
Associate Professor Yohei Yamaguchi
https://researchmap.jp/read0140668?lang=en

Abstract
This study develops simulation models to estimate energy demand and carbon dioxide emissions for the Japanese residential
and commercial building stocks. The developed models (1) quantify the demand of the building stock as the sum of the energy
demand of individual households and commercial buildings, (2)simulate human activity in estimating the energy demand, and (3)use a building stock model that represents the heterogeneity of thestock composition and changes over time, which is designed toprovide the analytical capabilities needed for the decarboniza-tionof the building stocks.

Energy▍ Background & Results
Decarbonizing the residential and commercial building stocks is
an imperative to mitigate climate change. The Japanese government has set a goal of halving carbon dioxide emissions from 2013
levels by 2030 and achieving carbon neutrality by 2050. To realize
this goal, it is necessary to introduce various technological measures, such as improving the energy efficiency of buildings, building
systems, and energy-consuming appliances, electrifying the energy source for space heating, cooling, and water heating, and theuse of renewable energy sources such as solar power generation.
Lifestyle changes, including behavioral changes, have also been
attracted attention. To achieve the carbon dioxide emission reduction targets, it is necessary to address the question, “when and towhat extent will these measures need to be introduced?”
As a result of applying the developed method to the Japanesecommercial building stock covering the offices, hotel, medical,retail, and school buildings, it was found that A) significant reductions in carbon dioxide emissions are achievable, B) the expected
increase in electricity demand due to electrification for space heating, cooling, and water heating can be avoided by improving energy efficiency through the introduction of various energy conservation technologies, and C) the dissemination of energy efficiency
measures is expected to reduce CO2 emissions by 27 MtCO2/yearby 2030 and has a potential to reduce by 43 MtCO2/year, compared to 148 MtCO2/year in FY2013.

Energy demand quantification procedure for the Japanese commercial buildingstock

Estimated energy consumption for the Japanese commercial buildingstock▍ Significance of the research and Future perspective
We are currently using the developed models to assess Japan’s
progress in reducing carbon dioxide emissions in the residential
and commercial building stocks and to develop decarbonization
scenarios for Japan that include behavioral and lifestyle changes.
In addition to this, we are developing an agent-based human behavior simulation model that stochastically simulates people’s time
use and travel behavior, and estimating energy demand of electricvehicles based on the behavior simulation result to analyze changes in energy demand comprehensively.

Contributions of factors providing reduction in CO₂ emissions. ECM: Energy conservation measures

P a t e n t
Yamaguchi, Yohei; Yoshizawa, Shinya; Shimoda, Yoshiyuki et al. Feasibility assessment of net zero-energy transformation of building stock using integrated
synthetic population, building stock, and power distribution network framework.
Applied Energy 2023; 333: 120568. doi: 10.1016/J.APENERGY.2022.120568
T r e a t i s e Li, Yuanmeng; Yamaguchi, Yohei; Shimoda, Yoshiyuki. Impact of the pre-simulation process of occupant behaviour modelling for residential energy
demand simulations. J Build Perform Simul 2022; 15: 287–306. doi: 10.1080/19401493.2021.2022759
Yamaguchi, Yohei; Kim, Bumjoon; Shimoda, Yoshiyuki et al. Building stock energy modeling considering building system composition and long-termchange for climate change mitigation of commercial building stocks. Appl Energy 2022; 306: 117907. doi: 10.1016/J.APENERGY.2021.117907
UR
L http://www.see.eng.osaka-u.ac.jp/seeue/seeue/K e y w o r d climate change mitigation, building stock energy demand modeling, decarbonization, building sector