Photovoltaic system: Advantages and disadvantages, experiences, worthwhile?

There are two types: a maximum of 70% or participation in feed-in management: 100%-60%-30%-0% ... With a pure south-facing roof, that's the question. In my opinion, a battery in the basement is uneconomical.

Even participation in feed-in management brings very little benefit. The costs for the ripple control receiver and the annual fees are usually higher than the compensation for the typically additionally feed-in energy.

That's why Fronius inverters are very popular. With a simple meter costing about €50, you can implement a soft 70%. That then gradually pays off over the amortization period.

Honest question to you all ... is it really still worth it compared to 10 years ago?

Yes and no. Feed-in tariffs have decreased, but photovoltaic modules have become significantly cheaper. Added to that are heat pumps and electric cars as sensible storage and self-consumption solutions, as long as the car is parked at the house during the day.

The highest profit is still for the photovoltaic installer, who pays €150 per unit to the Chinese importer and installs it on your roof here for €1000.

Yes and no. The feed-in tariff has been reduced, but photovoltaic modules have become significantly cheaper. Added to this are heat pumps and electric cars as sensible storage and self-consumption solutions, provided the car is parked at the house during the day.

I once compared my return from a current system with that of my father-in-law from the heyday of subsidies. For roughly the same amount of money that I pay today, he got a much smaller system back then. But his subsidy was much higher. In the end, his return is slightly higher than mine. It is still worth it for me as well.

The highest return is still for the photovoltaic installer, who pays €150 per unit from the Chinese importer and installs it on your roof here for €1000.

What do you mean by a unit? A module? Unfortunately, the margins are not that high...

kwp

goes down to 100€ / kwp

plus all the installation stuff, control electronics, inverter, etc. of course

I am digging up this topic here to maybe get a question answered:

The economic efficiency of photovoltaic systems is rather poor in winter (where most heating/hot water is needed) and pulls the average down.
But how does it look, for example, in summer? Assuming you include an air-water heat pump or a brine heat pump in the calculation and then supplement the whole with a module for cooling in summer. That would generate a significantly higher yield from the photovoltaic modules for cooling, right?

Regarding batteries/storage, I have read mixed opinions so far. How does this look in a single-family house with something like that? Especially with a targeted KfW 40+ subsidy?

Well, a lot is being mixed up here.. You cannot generate a higher yield with more self-consumption. Producing self-consumption deliberately for the sake of consuming is the opposite of economical. A battery is never economical, you can calculate that in 3 minutes. A photovoltaic system is only economical because of the feed-in tariff, optimizing self-consumption increases the economic efficiency.