The situation in my corner of the US makes it uneconomic to sell back to the grid. Pricing is also tiered in a way that means that only high-consuming households are likely to get a decent ROI; I pay less per watt, from my modest house with beautiful solar exposure, than someone whose larger household consumes twice as much electricity. Energy sold back gives me even less than I would save by using my own; home generators are paid much much less than even lower price tier consumers are charged.
There are additional details that make things even worse - e.g. you should avoid installing solar in anticipation of a major increase in your consumption - you need at least two years in your new, higher-priced tier first for better financial results. I envy you living in a political jurisdiction with somewhat saner incentives.
Note however that all this is from memory. I investigated some years ago, when installation was still subsidized - and even with the subsidy, it didn't seem financially worthwhile. So I chose not to purchase either an electric vehicle or the solar panels that would have kept it in "free" power. sigh