Photovoltaic system air-water heat pump - profitability single-family house KFW55EE

Meal time,

The system shows that our self-consumption was 55.5% last year. Since the year generally wasn't that great, we are satisfied for the first year. Let's see if we can "optimize" a bit more this year?

Mmh, I would dare to say that it is smarter to operate a 10kwhp system with 30% own consumption than a 4.8 with 50%.

Well, 3kW self-consumption versus 2.4 is of course better at first. The question is whether the 25% extra own consumption also justifies the price for a system twice as large. With a feed-in tariff of 6.x cents that I will receive for my system, it is questionable whether that is not below the production costs. Good 1000 kWh per kWp are to be expected, which amounts to 1200-1300€ over 20 years. Sounds not bad at first, but that is roughly the amount it costs to mount it on the roof, excluding opportunity costs and loss of money value over this time. But we’ll see, maybe the new government will still change something in time

well, those who already have a system will certainly not suddenly get more, and if the photovoltaic requirement comes, everyone has to install one anyway, so no incentives are needed anymore :p

With a feed-in tariff of 6.x cents that I will receive for my system, it is questionable whether this is not below the production costs. You can expect a good 1000 kWh per kWp, which amounts to 1200-1300€ over 20 years.

With a smaller system, however, you have the same problem. Even more so, since smaller systems usually have a higher price per kW than larger ones. In absolute terms, with larger systems you can use more electricity yourself, especially in winter or during off-peak times, since a bit more power is generated then. You can read about how this is viewed in a very well-known forum on the topic.

With a smaller system, however, you have the same problem. Even more so, since smaller systems usually have a higher price per KW than larger ones

It depends on how you calculate. For us, the walls were already quite good, and I could also make the argument that the minimal system with minimal storage costs nothing at all due to the jump from KfW55 to 40+, and every additional module has to justify itself financially. And that not with plus/minus but against a profitable investment of, say, 5% per year. But anyway, I need to have the solar person from the general contractor give me options for expansion. I still have the idea in my head to mount something on the carport to get a second exposure (SSE on the house, WSW on the carport). But that would, of course, be a second installation. One problem with forums is that each forum has its own community with common sense and overlooks certain things. In the house building forum, investment is primarily real estate, the solar forum calculates how much can be saved with solar systems, and in the stock market forum, stocks are the absolute highlight. Weighing all of this against each other is not that easy.

Self-consumption determines profitability today. It’s no use producing zillions of kWh that feed in at 7-8 cents while you pay much more for your own electricity.

Surplus is the secret though. Feeding that in at 8-9 cents isn’t bad either.
Of course, that doesn’t sound like much. And with a 5 kWp system it’s nothing, so fill the roof completely and benefit from it as long as possible. That’s at least my plan.
But now our roof shape "hip roof" is throwing a wrench in the works.

Roughly speaking, for our region with all costs, with 25% self-consumption, the system pays off after 10-12 years.
Stiftung Warentest has a very good calculation tool for this. Or in the photovoltaic forum.

Of course, I can also be wrong.