Photovoltaic system for hot water preparation and feeding

The BWWP costs only a "few euros" extra. However, it saves about half of the electricity for water heating compared to an instantaneous water heater. Instantaneous water heaters definitely do not fall under the category of renewable energies, regardless of whether they are operated with photovoltaics. I know this because we currently have two of them and have to switch to meet the KfW Standard 100. Photovoltaics are far from sufficient for normal self-consumption in winter, let alone for heating. That is more for spring/autumn. With my 7.28 kwp system, I sometimes only get 1-2 kWh per day in winter (for comparison: in summer with sun it is 45-48 kWh per day!) and I have a south orientation. That is not nearly enough. I also don’t quite understand the logic why a BWWP costing 700-1000 euros should be uneconomical, but a 15k euro air heat pump for heating is not. Although the BWWP operates at room temperature, i.e. +20°C, whereas the air-water heat pump has to work with outside temperatures (we had -15°C last winter). Indach is more expensive, stay under 10 kwp! (As far as I know, there is a small system regulation up to 10 kwp, but google that again.).

But why are 30% of the 10kW system 3000 kWh?

Now you have confused me.
A 10 kWp system produces about 10,000 kWh per year as far as I know (obviously regionally dependent around 8700-9300 kWh).
Therefore, 30% of that is about 3,000 kWh.
Am I making a mistake in my thinking here?

Yes, because a 10 kW system delivers 10 kW at peak – this has nothing to do with the annual output.

That means one will feed in less over the year as a whole, since the winter months yield little, right?

Yes, because a 10 kW system delivers 10 kW at its peak - that has nothing to do with the annual output.

Ah - OK. Then that was indeed a mistake in my thinking. My system has been running since September last year. So I still have a good 3 months (high summer) to see how big the difference between nominal power and production output is. Let's see.

and how are you doing now with your system?