This is an update on July 2, 2020.
On June 30, Takehara New No.1 started its commercial operation. This plant is operated by J-Power, locates in Takehara city, Hiroshima.
On July 1, Kashima No.2 started its commercial operation in Kashima city, Ibaraki. This plant is operated by Kashima Power which is owned by J-Power and Nippon Steel.
Now, the number of units under operation (including trial operation) is 19.
Please see the web for detail. https://sekitan.jp/plant-map/en