Yuya Takane, Senior Researcher, Environmental Dynamics Evaluation Research Group, Environmental Creation Research Division, National Institute of Advanced Industrial Science and Technology (AIST), and Nori Nakajima, Research Fellow, Photovoltaic System Team, Renewable Energy Research Centre, AIST, together with Professor Yukihiro Kamegagawa, Meisei University, and Senior Researcher Kazuki Yamaguchi, Tokyo Electric Power Holdings Co. As part of an assessment of the impact of high temperatures on energy consumption, etc., the actual state of electricity consumption in the Tokyo metropolitan area was clarified and future changes in electricity consumption due to climate change were estimated.

The results showed that future global warming could lead to a significant increase in electricity consumption, particularly in the office blocks of the city centres.

The estimation of changes in electricity consumption was based on detailed big data on electricity consumption in the Tokyo metropolitan area and global warming forecasting technology. By combining this estimation method with an urban climate model originally developed by AIST, it was newly possible to estimate how future changes in electricity consumption could change with the spread of decarbonisation technologies.

This new estimation method has shown that the increase in electricity demand due to air-conditioning use in buildings in city centres could be halved in the future, assuming that decarbonisation technologies become more widespread. This result indicates that the increase in CO2 emissions from electricity could also be reduced by half, assuming that the power supply mix remains unchanged in the future. These technologies and the estimated results are useful for assessing the effectiveness of deploying decarbonisation technologies to achieve carbon neutrality in 2050, as well as heat island control technologies to combat hot weather.