Prefab house made of Neopor - experiences?

Oh no, before going into detail, you first have to ask yourself why you want to insulate a house to passive house standard, only to then heat with electricity and thus have higher heating costs than in a standard Energy Saving Ordinance house... A fireplace in a passive house is also a no-go. The most important thing is "keep it simple", pairing a hundred different heating options ends in a disaster. Well, I find the poured Styrofoam cubes creepy, but that is certainly subjective, whoever likes it.

I somehow don't find the concept convincing. On one hand, simple robust instantaneous water heaters that are also cheap, on the other hand wind turbines and storage, both things that never pay off according to all the sources I know so far. If you see the whole thing as a hobby, okay, but from an economic perspective, no. You can heat for a long time with the additional investments. What the power companies sell as a power cloud is just marketing nonsense that also costs 20€ a month. Your own electricity is only given back virtually.

The house is being built in a windy region with free exposure from the west, south, and east. Thus, it can already pay off after 15 years.

However, the exact concept is not stated there.

The focus is on a small fireplace located centrally in the living area, which thus reaches almost the entire ground floor. It is also supposed to heat the buffer.

The tube collectors take over the hot water preparation from March to October, as well as partly in winter.

If the wind turbine actually comes, there will also be an [Estab] in the buffer so that no electricity is fed into the public grid but everything is consumed by oneself.

For air conditioning, there are 3 inverters from Mitsubishi. With them, you can cool and heat.

Flow heaters are only used in case the available energy is not sufficient.

It's just not economical, expensive to maintain, and labor-intensive. But at least it's expensive to purchase. Why don't you take something proven?

What are you referring to now?

Wind turbine, water fireplace, collectors and inverter in combination. Why are you doing this? Are you interested in the technology or have you always wanted to build something like this?

Because as written, it is not economical and complicated. I have no idea about wind turbines, but when you already write "can pay off after 15 years" it sounds like when someone says "photovoltaics can pay off after 5 years". It is possible but not the rule.