Preliminary construction planning, heating issues

So an architect (if not specialized in this) rather not. I would rather go to an engineering consultant for building physics calculations or to 1-2 suppliers of such systems and ask what you can expect based on experience with such a system.

Oh, regarding energy demand:

A heat pump also consumes electricity but provides you with three times the electrical input as heating power from geothermal energy.

More understandable: about 1 part electricity + about 3 parts geothermal energy = 4 parts usable heat energy (may vary slightly depending on model and manufacturer).

You can definitely regain this electricity through photovoltaics. The decisive factor here is your annual balance => In summer, you get paid for the electricity you feed in, which you can then use to buy electricity in winter when you have increased demand. The rest of the system, besides the heat pump, mainly consists of small motors that keep the circuits running (pumps for e.g. ground heat collectors and pumps for controlled room air) plus their control electronics.

But to be able to calculate the heating demand of the house and thus the size of the entire system, some key data is needed or must be assumed (number of occupants, area, heating demand (and thus the approximate location of the future building), and much more).

Thus, such calculations are relatively pointless if you do not have a specific project calculated.

However, you can roughly estimate which requirements the house must meet (insulation, airtightness, heating system) and thus the approximate rough costs of the passive house compared to a normal house.

I hope we were able to help you somewhat in this regard.

And as my predecessor already mentioned: besides deep and surface collectors, there are various hybrid forms (ground heat baskets, etc.) and variations. Such systems can also be applied in foundation concepts (e.g., bored pile walls or even tunnel walls). But I did not want to go too far because my "lecture" has already become quite long ;-)

Regarding your question about problems:
Usually, there are no problems with such systems. However, it is not completely risk-free (at least with deep collectors). Possible issues I see here involve pressurized groundwater (groundwater under pressure => if drilled, it may escape through the borehole), but this is usually very rare. Additionally, for such systems (at least here in Austria), a water law permit is necessary because the microbiological system in the soil/groundwater can be affected by temperature changes. This permit should not be a problem but should be applied for as early as possible so that you do not experience unpleasant surprises if things do not run smoothly immediately. But the biggest risk should be excluded by a soil survey (which you need anyway for choosing the foundation of the house, possibly somewhat more detailed).

Oh, and a little tip:
Definitely get legal expenses insurance before building and, if possible, also a construction-surveying expert/consultant, because small causes can otherwise result in serious consequences if not detected early. And it already starts with the proper and professional installation of windows and doors and continues through to sealing the basement/foundation. That way, not much can go wrong during construction.

Best regards, Thomas

.....or who does something like that?

A TGA planner and energy consultant are probably suitable for this ;) You can send me a private message.

Best regards

Hello, thank you all for the informative answers.

@Thomas463
Of course, I can produce the electricity myself again. It would even be sensible because, due to the changed photovoltaic compensation for self-consumed electricity, I now get at least 30% more than if I directly feed the electricity into the grid. Unfortunately, there are still no really good and affordable batteries to store the electricity that is not used directly for a long time.
I definitely have to have a soil survey done. For a normal basement, I believe I only have to have a survey done up to five meters deep. Anything deeper then has to be commissioned additionally.

@€uro
I will definitely get in touch with you. Thanks

Hello, thank you for the informative answers.

@Thomas463
Of course, I can produce the electricity myself again. It would even be sensible since I now get at least 30% more for self-consumed electricity due to the changed photovoltaic tariffs than if I feed the electricity directly into the grid. Unfortunately, there are still no really good and affordable batteries to store the unused electricity for the long term.
I definitely have to have a soil survey done. For a normal basement, I think I only have to have a survey done up to five meters of soil depth. Anything deeper then has to be commissioned additionally.

@€uro
I will definitely get in touch with you. Thanks

YES, storing with batteries yourself can be forgotten, but simply feeding into the grid and drawing electricity from the grid when needed is possible. So the grid basically serves as a battery ;-).

Well, you can’t generalize the five meters. It depends on how deep you have to drill to reach good and load-bearing ground. It can deviate significantly from five meters on a slope or in backfilled terrain.

For a deep probe, you should drill deeper, but if the drill rig is there anyway, it shouldn’t cost that much extra. Although you should already know in advance which type of geothermal use you want to apply. That also depends on what exactly you need.

But I hope we were able to set you on a good path for your first considerations in construction.

Best regards, Thomas

Hello, of course self-feeding is currently the only solution. Although, as I said, I get more compensation for self-consumption than if I feed the electricity directly in. But that will be worked out. :-) So on the site where construction is to take place, definitely nothing has been filled in. I will probably decide on deep probes. For surface probes, a huge amount of earth would have to be moved again.

Best regards.

The deep probe is in and of itself very good. The deeper you go into the ground, the warmer it is there.

Add a heat pump, controlled room air with a heat exchanger for heat recovery, and you have a good system in hand.

Oh yes: you can also lead the pipe for the fresh air supply several meters underground at about 2-3 m depth to the house, and then the air is additionally somewhat pre-warmed in winter or pre-cooled in summer ;-).

Best regards