Cleaner:

Global production capacity for solar volatic elements is currently around 60 gw (rated). About half of this productive capacity is in search of buyers.

The japanese government just gave them a market for the entirety of this potential output, and the average japanese household can make this investment without having to loan the money. I expect them to do so, because the return is so very high. Further, productive capacity in this sector has doubled year-on-year to meet new demands before. It is not a strech to suppose this will happen again. Thus, by the time the law expires, it within the realm of physical and engineering possibility that over 400 gw (Rated) of solar has been put up in japan. And as long as the law is on the books, financial incentives make this maximalist scenario quite likely. This is just the solar sector - sales of windmills and so on to Japan are also likely to be extremely strong.