Meaningful energy concept for new Kfw70 construction without oil or gas

Hello,

we want to build in the next 1-2 years, about 170-190 sqm for 5 people, Kfw70 standard. We definitely do not want gas or oil.

We have imagined an air-to-air heat pump with automatic house ventilation and exhaust ventilation as well as heat recovery and domestic water heating through waste heat (as seen with a prefab house provider).

Since you would of course have to heat with expensive electricity, we would like to combine this with a photovoltaic system.

What do you think about that? Acquisition and running costs compared to a conventional heating system?

As further options to complement, I also have solar thermal and a wood stove (with heat storage?) in mind but am skeptical whether this can be harmoniously integrated. It should of course also be economical in the medium term.

In terms of acquisition costs, you chose the most expensive option. You are installing almost everything into the house that is available besides gas & oil. The photovoltaic system then provides the least electricity when you need it most: in winter.

From many discussions about controlled residential ventilation ("house supply and exhaust ventilation and heat recovery"), the main consensus can be read that this technology is something for comfort (if you like this kind of comfort), but it never pays off.

Air-to-air heat pump requires a lot of electricity for such a large house, annual maintenance, and is a complex device. Personally, I don’t like these things, but that’s a matter of belief that I do not want to raise here for the umpteenth time.

Why no gas? For ecological reasons?

Why no gas? For ecological reasons?

Hello, I would like to be (more) independent of rising energy costs.

The technology you listed requires huge amounts of electricity. You are just as dependent on energy costs with it. You can take a look at the price development for electricity over the last 15 years. No one expected that. Also not that, for example, oil is currently very cheap because the USA completely covers its own demand (and even partially exports) and the world economy is stagnating, thus consuming less. The gas price, in turn, depends on the oil price. Political influences such as the energy transition and the foreign political general situation cannot be predicted at all.

I personally believe that energy prices cannot be predicted well enough to base the decision for one or the other energy source in the house on the forecast.

OK, then let's leave out the air-to-air heat pump with [Kontrollierte-Wohnraumlüftung]. What would you consider sensible from the rest? Would a wood log fireplace (with heat storage) for the winter and solar thermal for the summer be sufficient for heating and domestic hot water? Or is the gas connection absolutely necessary?

You should write why a gas heating system is a problem for you regarding the flow temperature. Then it would be easier to address the question. Because a gas heating system is basically sensible.