Heating question new building KFW 70 air heat pump + solar, ice storage?

The current remuneration for under 10KWp is 12Ct/kwh. About 10 Ct are the own costs. 1 KWp costs around 1500 Euros, 20,000 kwh will be generated in 20 years with it, plus proportional costs for the inverter that does not last 20 years, resulting in the 10Ct. I can only pass on my data, however, everyone should achieve 30% because you don’t work every day but only about 200 days out of 365. By the way, you don’t have to eat a warm meal in the evening if you have already eaten one at noon in the canteen. The second 20 years will be cheaper, then the costs are only about 1 Ct/kwh.

The calculation does not convince me, as many things are missing from the costs (connection, installation, fees?, all included in the 1500?, insurance increase), which then make it more expensive. These small things add up. Many people also work a few extra days. And when you are on vacation, maybe during the good weather period, you are not at home at all, so basically ZERO self-consumption! Overall, this means (since efficiency also decreases over time) that fed-in electricity is almost zero. If the small insurance cost for 20 years is only 400 (only 20 euros per year! more, this could also become more expensive), your kWh then costs 2 cents more each and you are at a loss when selling! (at 70% of the production). Too uncertain, especially if the feed-in tariff decreases...

This is the price per KWp for an installed system, about 5 KWp. There are no small things here. The insurance of 40-50 euros is paid for the entire system and after at most 10 years unnecessary because the inverter will then be old anyway and the modules keep getting cheaper if one should break. There are 30-year-old photovoltaic systems that still produce over 90% of the power. On average, every employee is sick for 18 days, in Germany there is also a retired life and there are enough devices that consume electricity in absence. The feed-in tariff applies for 20 years, but electricity costs increase annually. The higher the electricity prices rise, the more profitable photovoltaics become every year, thanks to self-consumption. No, those who do not have photovoltaics have themselves to blame.

No, those who don’t calculate properly are also to blame. In all cases, you pick out the best-of numbers for your calculation, neglect maintenance costs, and that doesn’t add up. You calculate with the cheapest system, best yield, and longest durability. A high-quality system can easily cost several thousand euros including installation and everything; you can have higher maintenance costs (which you hardly list here), maybe after 10 years someone has to clean it (depending on location), and so on. That’s cooking the books if you omit the "small" thing of 1,000 euros for insurance (for the 20 years) in the calculation and other things. After 10 years, cancelling insurance because the modules are then cheaper – in the last 10 years they haven’t become that much cheaper, so that’s pure speculation. Also, and that’s what I meant about insurance, your household/ fire etc. insurance usually gets more expensive with a solar system; just try telling the insurance company after 10 years that you still have the system but don’t want to pay. And even if you cook the books, it’s pretty close to the feed-in tariff; too close. Since all of this is just a rough calculation, you can also end up at 12 or 14 cents cost per kWh here! And now explain to me how I’m supposed to generate EV reasonably in my absence. I would now be on the island for 3 weeks, how do you do that? I think it’s very individual for every household whether it’s feasible without storage or not, and not as simple as you portray it. If you also retrofit household appliances or buy new ones so that it works, you also have to add these costs to the electricity costs of the photovoltaic system and then it definitely doesn’t pay off anymore (that quickly adds up to thousands). By the way, electricity has not become more expensive, only the state has added higher surcharges like for the feed-in tariff, so that end consumers pay more. Therefore, in 20 years (crystal ball mode on), the feed-in tariff will most likely be lower as well. Otherwise, people usually don’t calculate much beyond 20 years; then the system has to have “paid off,” so you basically don’t need to calculate much beyond that period; besides, it’s too much speculation what will be then. I don’t think you really make a profit with solar or that it’s really worthwhile. But at the moment you hardly get any interest for your money either, so if you really have money left over, you can put such a system on your roof; also, it gives you a good conscience. When you again safely get 4% interest on your money, you would have more from that than from solar (and it’s much easier).

Quick question about insurance. Which insurance, besides his household contents insurance, do you still need? That generally also covers the photovoltaic system (unless it is a stingy contract without benefits). We therefore have no additional insurance and thus no costs.

Whether the 10 cents fit is another question. If I just look at the taxes on self-consumption, I dare to doubt it...

I think the building insurance is more expensive. And the fire department is also not so enthusiastic about [Photovoltaik]