"Currently named "Battery Tanker X," the prototype won't be going very far. Pushing a vessel through draggy water is a nightmare for battery-powered electric propulsion systems, so the ship's maximum range before it burns through too much battery to make the trip economically feasible is slated at just 300 km (186 miles).

A full production "Power Ark" the same size, says PowerX, might move about 4,190 GWh of electricity annually from renewable sources in Hokkaido to meet demand in Aomori just 100 km (62 miles) away, making use of transmission infrastructure already in place but soon to be abandoned as fossil fuel-based generation capacity is gradually shut down. "

I'm reading a lot of comments seemingly missing these details. Interesting and seems to be useful in Japan's geography that I'm not personally used to thinking about.