The two companies will start generating electricity from the 111MW array on 1 December, on a 166-hectare plot of land in the town of Abira, on the northern island of Hokkaido.
They did not reveal which company supplied the PV modules for the project, which was first announced in September 2013.
The partners — who each hold 50% stakes in the project — initially aimed to complete construction in early 2015.
The
