SolarEV City concept: Building the next urban power and mobility systems

The SolarEV City assumes that 70% of toof-top of cities at maximum are used for PV and all passenger vehciles are converted to EV in cities being used as batteries for PV electricity. We conducted technoeconomic analyses to evaluate the concept in terms of CO₂ emission reduction, cost savings, energy suffciency, self-sufficiency, self-consumption for nine Japanese urban areas (Kyoto City, Hiroshima City, Korimaya City, Okayama City, Sapporo City, Sendai City, Niigata City, Kawasaki City, Special districits of Tokyo).

Our analyses indicate that implementations of the concept can meet 53-95 % of electricity demands in nine major Japanese urban areas by 2030 with the use of 70% of roof-top area in the cities. CO₂ emission from vehicle use and electricity generation in these areas can be reduced by 54-95% with potential cost savings of 26-41%. High cost-effectiveness and seasonally stable insolation in low latitudes may imply that the concept may be more effective to decarbonize urban environments in emerging economies in low latitudes.

Among several factors, governmental interventions will play a crucial role in realizing such systems, particularly in legislating regulations that enhance penetration of the integrated system of PV and EV and enable formation of decentralized power systems. As bottom-up processes are critical, policy makers, communities, industries, and researchers should work together to build such systems overcoming social and regulatory barriers.