Using electric vehicles to power houses or travel during blackouts triggered by natural hazards: A choice experiment in Japan

• During blackouts, EVs can be used to power houses or provide transportation. • This study presents a choice experiment for using EVs for two purposes in Japan. • The choice probability depended on the blackout conditions (e.g., season and weather). • The probability also varied depending on the household characteristics. • The study presents practical and policy implications to increase EV benefits. Electric vehicles (EVs) can power houses during large-scale blackouts caused by natural hazards. However, during natural hazard-related disasters, EVs are essential for transportation to obtain supplies and for other purposes. This study focuses on the conflict between powering houses with EVs and using them for transportation during natural hazard-triggered blackouts. We assessed the conditions under which the choice between using EVs for powering houses or traveling varied. In particular, we conducted a choice experiment with EV-owning households in Japan, using a questionnaire based on the stated preference approach. The respondents were presented with a hypothetical scenario immediately after a blackout caused by an earthquake. They were asked whether, in the case of a blackout, they would prefer to use their EVs for traveling or powering their houses while considering the season, time of the day, weather, and EV battery level. We considered two travel destinations: 1) shopping centers (to obtain supplies) and 2) public charging stations (to recharge EVs). Based on responses of 300 individuals (150 individuals for each destination), we used discrete choice models to identify the blackout conditions and household characteristics that could influence the choice. Overall, individuals preferred using EVs for powering houses rather than for traveling to each destination; however, this tendency varied by conditions and characteristics (e.g., stronger on rainy days, but weaker in spring or fall, or among households with people requiring care). Based on the results, we suggested measures to enable the use of power at home while achieving the purpose of traveling.