In my country, you have no right to store "fluids" (meaning hot water you could produce with solar during the day, used at night for heating the house for example).
Weird, what country are you in, and what is the justification? Are you not allowed to have hot water heaters or radiant floor heating? Seems pretty hard to enforce.
in some, included USA, you could have situation where it is forbidden to be off-grid, so your are obliged to pay the tax, even if your local production cover all your needs and even more.
This is often true and it irritates me, but in the cases I'm aware of, this has to do with local and regional building codes and city ordinances, and overbearing planning departments. Though I wouldn't be surprised to learn there that there is pressure or lobbying by the utilities companies to mandate grid connection.