Consultation for photovoltaic systems

One should always occupy all available areas. The larger the system, the cheaper it becomes, as the fixed costs (electrician, inverter, scaffolder) do not change significantly. If PVGIS outputs values below 650, it can possibly be omitted. But this only occurs with roofs oriented exactly north, steeper than 25°. So not very often.

Full agreement. Additionally: an orientation for maximum yield was important at the time when the feed-in tariff was the main economic factor and self-consumption was at most a "nice to have." Today it is different, as the remuneration per kWh is far below the purchase price. So if you can cover your self-consumption in the morning hours with the northeast modules, it is very possible that this expansion is very worthwhile.

Storage is currently neither ecologically nor economically sensible. (Not for a long time yet)

I see it differently – it depends on the consumption curve and the purchase price, ultimately the annual cycles – and of course the local subsidy program. It can be calculated.

Full agreement. Additionally: At the time when feed-in tariffs were the main economic factor, and self-consumption was at most a "nice to have," the focus was on maximum yield. Today it's different, as the remuneration for one kWh is well below the purchase price. So if you can cover your self-consumption in the morning hours with the northeast modules, it is very likely that this expansion is well worth it.

I see it differently – it’s a matter of the consumption curve and the purchase price, ultimately the annual cycles – and of course the local subsidy program. You can calculate it.

You have to calculate precisely for the storage. Especially because with the subsidy programs that actually bring the storage into a price-sensible range, you often also have to accept a feed-in limitation to 50% of the installed capacity (otherwise it’s usually 70%). But this is exactly where the northeast roof helps again, because it increases the installed capacity and flattens the feed-in power over the day, so that the system does not hit the limitation as often.

So calculate, calculate, calculate! At least if money matters and the OP is not just doing this to soothe their ecological conscience and as a hobby.

So calculate, calculate, calculate! At least if money plays a role and the OP is not just doing it to ease their ecological conscience and as a hobby.

Very nice subordinate clause - there are more reasons than just money to rely on self-consumption.
Although I can pay an eco-energy provider in our region, I still receive a coal mix because the power plants are so conveniently close. That is the principle of the balancing group.
On April 1st, I read a report that Munich would now also receive Gelsenwasser since the water market is being liberalized. Balancing group in this case would mean: You get the same water as before, but pay Gelsenwasser. It is clear to everyone that no different water can drip from the tap. With electricity, it is not very different.

I want to have a photovoltaic system primarily to save money and as a secondary goal to contribute my part to climate change

I will definitely calculate this and also calculate the photovoltaic addon on the terrace roof to see if it is economically worthwhile at all.

It would be nice if the photovoltaic system and terrace roof paid for themselves :D

I want to have a photovoltaic system mainly to save money

This is still a contradiction for me at the moment.

That is still a contradiction to me.

Why is that? A photovoltaic system should always be cost-effective.