If the information were available, I would share it. The stockworker extension will start no earlier than spring 2023. For this reason, there is so far only a factory plan from the architect and a heating specialist has evaluated it and offered the Weishaupt heat pump. The buffer storage tank is for storing the energy not needed.
Since we are laymen in this field, we are looking for another opinion and therefore the question of which manufacturer should be requested for price/performance. Whether the heat pump might be oversized we cannot say. This is just the result of the offer preparation. Thank you very much!