Renewable energy – mainly solar power – is expected to be increasingly rapidly integrated into future electricity systems in Japan especially after the Fukushima Nuclear Accident. On the other hand, one of the most crucial elements of future electricity systems will be the capability for “smart” controls on both supply and demand sides to perform under real-time dynamics. Therefore, the purpose of the study is to evaluate the impacts of integrating PV power into future electricity system with electric vehicles (EVs) and heat pumps (HPs) under smart control strategies in Kansai Area, Japan through scenario analysis. The analysis was conducted using a model that is organized into an input–output framework, and actualized using an hour-by-hour computer simulation to derive a real-time supply-demand balance. Electricity system scenarios with different penetration levels of PV power, EV and HP were obtained. The scenario results show that EV and HP are helpful for integrating more PV power by absorbing excess electricity in future smart electricity systems, and the high level penetration of PV power can reduce CO2 emission greatly and effectively. One million EVs and one million HPs can reduce excess electricity by 3TWh which is 2% of total electricity, and 30GWp PV can reduce a maximum of 11.6 million tonnes CO2 emissions which are 43% of total CO2 emissions. Finally, the annual and monthly operation patterns of EV and HP are also uncovered in different solar irradiation and temperature situations.