The option of returning electricity to the network, with compensation, is the right thing, when you live in a regulated country.
And imagine this situation:
You set up a system that on sunny and colder days can produce up to 50% of the electricity you need, and because the law did not regulate payment, you have to limit the system and spend the electricity on something unnecessary, because if you return it to the electricity distribution system, the meter is it adds up as if you spent it, not produced it.
(Serbia today, the company where I work)
That seems a little bit backwards but I think some countries do things differently to others; I'm fortunate to be in a country that pays for power back to the grid and that payment comes directly off my power bill. On one of my house I get almost zero dollar quarterly power bills. Not too bad huh?
For this house, you don't need batteries 🙂