In Australia that distance is certainly enough for completely different weather. But local geo-climactic conditions in Japan might be completely different; it's

In Australia that distance is certainly enough for completely different weather. But local geo-climactic conditions in Japan might be completely different; it's probably not the distance as much as prevailing winds, geography, etc. Interestingly for any type of generation - Japan runs two different grid frequencies, which limits cross-flow from one half to the other half. They do have HVDC interconnects, but are rather limited (they're building more, in no small part as a result of Fukushima)