Per fortnight, not per year, but yes, if you're only setting up one its hardly worth the trouble you go to the first time.
Discussion
that's actually better than I thought.
I think the problem is really with the excess. It is either rare and not enough to mine, or you have overpaid on the fv system, so your energy is actually expensive.
I can imagine two situations where it makes sense:
- you are traveling and not using the energy, nobody's at home
- you get access to spot prices and have batteries. when the energy is cheap or negative, you both mine and charge batteries (you can do this with Victron systems for example)
From a probabilist POV, there's no such thing as overbuilding for every scenario.
But you're broadly correct - I don't have the ability to sell back to the grid. Financially, I'm better off wasting the power than signing the contract that would allow me to sell it.
(Conservative governments here hate the free market more than Communists do lol)