We propose a method of estimation on the basis of model-based simulations by taking into consideration the lifestyles of individual family segments to manage energy over a wide area. We adopted a user model that effectively classified families during simulations that took into account the lifestyles of families. There is a risk of power shortages during hours of peak power demand over wide areas in Japan. Therefore, we focused on power supply leveling over a wide area by using electric vehicles in the home sector as storage batteries as one countermeasure to avoid power shortages. We applied model-based simulation in this study with a user model to evaluate the possibility and efficacy of power supply leveling by shifting peak power demand with electric vehicles in the home sector. We defined models of all actors that were related to power supply leveling in these model-based simulations. We defined four user models for typical family segments and predicted the possibility and efficacy of power supply leveling until 2050, by using the most effective family segment to compare possibilities and efficacies due to differences between family segments.