We’re living in a big river valley where we have fog from October until March. On some days in November the fog is so dense that the whole system does not produce any kind of energy. On the other days the produced kWh are enough to charge the battery.
We have a heat pump (extrem efficient), servers, one electric car, etc which consumes all together around 13MWh per year. The solar system produces around 27.5MWh. Most of the energy gets fed back into the grid.
We’re currently investigating to connect the neighbour houses physically to us. But that takes even more time here :-(
See eg https://www.swissolar.ch/fr/connaissances/nouvelle-loi-sur-l... (post written in French)
Just for comparisons sake, our 8.6kwP setup with a 10kwH battery cost us (after subsidies from governemnt) appr. ~€11.5k. Haven't received all the subsidies yet, so the total will be lower by about 1.5k (I think). Everything was done through installers, we didn't lift a finger (also couldn't, because when it comes to electricity I have as much experience as the dog next door).
If I had more due diligence before I would have scaled up the panels up to at least 10kwP, for future proofing probably to 12kwP. This is mostly just to make sure winter is covered better, as our production is really low as we have a 10° flat roof installation.