According to Japan's R&D roadmap ??PV2030??, a base-case scenario is showing that the mass deployment of 100 GW PV aggregation will supply 10% of national electricity up to 2030. About a half of this PV installation is assumed to be brought still from massive residential roof-top applications. In such a state, PV penetration will reach almost 100% in the majority of urban residential areas. Since the classical grid formation approach does not seems to be a good solution to deal with this issue, the author has already proposed ??Autonomy-Enhanced PV Clusters (AE-PVC)?? to realize a less dependent PV aggregation on the existing power grids in conjunction with grid power electronics and storage battery stations. Main contents are: (i) Case studies for residential towns and cities, (ii) Town grids mainly composed of massive residential PVs by considering fluctuating supply and demand; bidirectional power flows; daily cycle and irregular components; autonomous and decentralized control of town grid; necessity of battery stations or controllable power sources; autonomously controlled own frequency and voltage, (iii) Inter-grid coordination by autonomous and decentralized principle: interconnection through national grids with power producers; inter-town interconnections; asynchronous power routers and so on.