Agent-based simulation of local electricity sharing system: Can we charge all EVs in a city only with the PVs?

This paper extends the concept of our proposed [Yamagata and Seya, 2012] electricity storage sharing system as a complement or alternative to a feed-in tariff (FiT) to achieve CO2-neutral transportation in cities. In our proposed system, electricity generated from widely introduced solar photovoltaic panels (PVs) is stored in the "cars not in use" in a city. For example, 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 V2G system. The present study extends the system in the following two senses. Firstly, different from previous study, this paper uses actual ground area data (footprint) of each building to estimate PV supply, which may lead to more accurate estimations. The results show that although the entire electricity surplus (PV supply minus demand) could be stored without waste if 12% of the EVs not in use were utilized as storage batteries at an aggregate (city) level, there exist significant regional mismatches at the local district level. Hence secondly, based on the geographical electricity surplus estimates, this paper shows an example of "optimal" electricity storage sharing by looking at the geographical distribution of high-storage potential areas employing a spatial clustering technique based on heuristic.