Evaluating global residential energy demand based on decent living standards through bottom-up simulations

Mitigation of anthropogenic GHG emissions requires not only decarbonizing energy supply but also reducing energy demand. However, it is expected that global energy demand will increase along with future economic development. This is particularly significant for the Global South, where energy consumption may increase significantly. For example, dissemination of air conditioning facilities could increase heating and cooling demands. While previous studies have estimated the future cooling demand and availability of household appliances in developing countries, there has been a lack of detailed quantitative assessments of energy demand using bottom-up physical simulation models. Additionally, because existing models do not consider demographic dynamics, the impact of the sharing effect in households cannot be evaluated.

We extend a bottom-up household energy end-use demand simulation model, originally developed for entire Japan, to a global scale. This model replicates household demographics in various countries based on statistical data and simulates the operation of household appliances based on occupant behavior to estimate final energy demand. A distinctive feature of our method is the incorporation of various meteorological data, such as temperature, humidity, and solar radiation, to calculate heating and cooling demands by heat load calculation.

As setting conditions in our simulation model, we considered a scenario based on Decent Living Standards (DLS). Settings of the DLS scenario were established for basic household services, including floor area, heating, cooling, hot water supply, lighting, refrigerators, televisions, and cooking appliances. For example, in the DLS scenario, heating and cooling services are available in all rooms, with target temperatures set at 26°C for cooling and 20°C for heating. Household appliances are assumed to have efficiency equivalent to the latest models available in Japan.

Under these conditions, we estimated the minimum amount of energy in the residential sector needed to meet DLS in 191 countries, covering 97.8% of the world’s population. Overall, the global minimum energy need was estimated to be 18.2 EJ/year. Additionally, in comparison with the previous study, LED scenario, it was suggested that the impact of the sharing effects considered in our model contributed to the differences of estimates.