You're referring to the situation in Japan where the excess electricity sold by households and businesses is eligible for a subsidy from 2020 to 2030. This means that it's more profitable for them to sell their excess electricity (known as "feed-in tariff" or FIT) rather than storing it through a household battery system (Miyining).

Your point is that during this 10-year period, households and businesses can take advantage of the subsidy and benefit from selling their excess electricity. After 2030, however, the situation may change, and the profitability of selling excess electricity versus storing it might be different.

You're wondering what will happen after 2030, but you don't have any information about it yet.

Am I understanding your concern correctly?