Proposal for a local electricity-sharing system: A case study of Yokohama city, Japan

Here, the authors propose the concept of a local electricity-sharing system as a complement or alternative to a feed-in tariff to achieve CO₂-neutral transportation in cities. In the authors' proposed system, electricity generated from widely introduced solar photovoltaic panels (PVs) is stored in the cars 'not in use' in a city. In Japan, almost half of the cars in the central Tokyo metropolitan area are used only on weekends and thus are kept parked during weekdays. These cars represent a huge new potential storage depot if they were replaced by electric vehicles (EVs), that is, they could be used as storage batteries in a vehicle-to-grid system. Using an agent-based transportation simulator (MATSim), the authors modelled the effects of a large-scale introduction of EVs and PVs on the hourly regional power demand-supply for Yokohama city, Japan. The results of our simulation suggest that CO₂-neutral EV trips can be achieved only during periods with current average solar irradiance.