TEPCO Power Grid Inc announced May 17, 2019, that it will introduce "non firm-type connection," which is one of the "Japanese Version of Connect and Manage (C&M)" methods, to the trunk power system in the Chiba region of Japan on a trial basis as an effort to increase the connectable amount of renewable energy.
In the Chiba region, many renewable energy-based power plants applied for grid connection, and the Sakyo Connection of the trunk power system became congested. As a result, the entire grid of the Chiba region has no available capacity. Even in such a situation, with the non firm-type connection, it might become possible to connect a certain amount of renewable energy to the power grid, according to TEPCO Power Grid.
The Japanese Version of C&M is a method to promote the grid connection of renewable energy-based power plants by making improvements to operation methods without investing a large amount of money in the current power system. Specifically, it consists of (1) the "rationalization of estimated power flow," which calculates an available capacity based on the assumption that is close to the actual state, (2) "N-1 power control," which instantaneously blocks a power flow at the time of an accident by using a capacity for emergency use, and (3) "non firm-type connection," which newly connects a power plant on the premise of output control at peak times.
Among the three items, Japan's Ministry of Economy, Trade and Industry (METI) and the Organization for Cross-regional Coordination of Transmission Operators (OCCTO) implemented the rationalization of estimated power flow in April 2018. Also, as for the N-1 power system, they announced that they will consider specific revisions and develop an adjustment system in fiscal 2019-2020, planning to start full-scale operation in fiscal 2022.