Photovoltaic system: Costs, saving potential? - Experiences?

I think, as long as there is little discussion about what the actual matter is, everything is speculation. Some time ago, I had a conversation with an energy consultant from consumer protection. He complained that politics comes across with zero information.

If the compensation is lost due to the elimination, module sales will collapse and prices will fall as a result.

Prices will certainly continue to fall, everyone agrees on that. The idea that the market of German private households has any influence on this is a bold thesis.
Private systems will become smaller as the subsidies expire. The market for companies with flat roofs and high self-consumption is just really taking off again. Most of the modules go anyway into systems whose capacity is measured in megawatts. They are built and designed for that.

If you want to know whether you can run your air-to-water heat pump with photovoltaics, I can give you a clear no. On cloudy days (so when it’s gray), my 8.76 kWp system produces a meager 250 watts. That’s not even enough for the refrigerator.

I would estimate 15-30% photovoltaic electricity for the heat pump over the year. In winter, it is often poor, but not always. A heat pump running during the day is a good way to ensure that little or no electricity is fed into the grid on weak days. From spring to autumn, there is almost always enough electricity to produce hot water. My refrigerator needs 20 watts.

With the removal of the subsidy, the purchase is not financially worthwhile for a private household. Maybe for a clear conscience. A self-consumption rate of 70% would be necessary here to recoup the investment reasonably quickly (i.e., in under 20 years).

And prices will not drop much further. 900-1,000 € per kWp is the limit for smaller systems. With the removal of the subsidy, storage costs will rather increase. Then it definitely does not pay off anymore.

Just had the second solar installer in the house. Same question as to the first regarding the elimination of the feed-in tariff upon reaching the cap. His statement, consistent with the first solar installer: it does not affect small systems. Now I am maximally confused.

Excerpt from the amendment proposal of the RLP State Parliament:

The Renewable Energy Act regulates that upon reaching a nationwide expansion level of 52 GW of installed photovoltaic capacity, the applicable values according to § 48 Renewable Energy Act for non-tender-bound solar energy are reduced to zero. This 52 GW cap thus effectively ends the Renewable Energy Act remuneration for solar energy in the segment up to 750 kWp, which do not participate in the tender. However, for other direct marketing according to the EEG, small photovoltaic systems are hardly suitable. For operators of a photovoltaic system in the mentioned segment, only self-consumption remains as an operating model.