Nearly 3 million households throughout Hokkaido are without power following the strong earthquake that struck the northern prefecture early on Thursday morning.
The industry ministry says the tremor shut down the largest thermal power plant in Hokkaido, the Tomato-Atsuma plant, which in turn led to a shutdown of all other thermal and hydro plants in the prefecture.
The ministry says the shutdown of the Tomato-Atsuma plant caused power demand to far exceed supply, making it difficult to maintain the power frequency. This forced the shutdown of other plants as a safety measure to prevent equipment damage.
As a result, about 2.95 million households across Hokkaido are left without power.
Hokkaido Electric Power Company has resumed operation of 4 hydropower plants. But the electricity generated there is being used for operations to restore the thermal power plants, and it is still unable to supply power to homes and companies.
The utility is also conducting inspection operations to search for damage to power cables and substations across the prefecture.
The industry ministry says there is a power transmission line to supply power from the main Honshu island to the northern island prefecture. But it says power cannot be provided unless power in Hokkaido is restored to a certain extent.
The ministry says if operation resumes at the largest Tomato-Atsuma plant, all other thermal plants can go online.
The ministry has ordered Hokkaido Electric Power Company to start getting the power plants working as quickly as possible.