Power consumption of a heat pump

Thank you very much for the many interesting contributions! I cannot see a convincing explanation for the power consumption around 4:00 AM. Why should the heating element always turn on at the same time at night if no hot water is being used?

Crazy. You have to be close to brain death to argue about the meaning, purpose, and sizing of your photovoltaic system based on its daily performance, especially in winter. That would be like two diesel drivers arguing, both of whom drove on the A2... but one at 100 km/h alone and empty, and the other at 180 km/h fully loaded. This is the (intellectual) level currently being displayed here.

For this (good) reason, there are statistics. They provide us, for example, with average values over many years... And these simply state that you can only expect about 15% of the July yield from photovoltaics in December. That there was now a day with more at MyGoodness... neither the statistics nor anyone else except MyGoodness and RotorMotor cares.

Also, that a south orientation with 45° would be optimal is not correct. You reach 100% with a south orientation at 28°. If you're already counting peas and calling others idiots, MyGoodness...

If you see this here as a "low-level argument between people close to brain death," that's your business (even though I don't understand why people always have to start a discussion with insults). I merely responded to the following statement from Buchsbaum:

Photovoltaic yields are very low from November to February. Today I had 3.5 kWh yield and that was already a lot.

I wanted to point out that there can also be more productive days in winter. Of the 17 days in December so far, I had over 15 kWh yield on 5 days alone, 3 of them even over 20 kWh. I was only below his stated 3.5 kWh, which he regards as "a lot," on 6 days.

You even underline my statement with the sentence that the average in winter is 15%. For me, it is even a few percent more, which, in my opinion, is due to the 45° roof pitch (low sun in winter and so on...).

Also, that a south orientation with 45° would be optimal is not correct. You reach 100% with a south orientation at 28°. If you're already counting peas and calling others idiots, MyGoodness...

I never claimed that either. You should also read properly. My exact statement was that 45° "really bring a lot" in winter and I still stand by this statement. A friend of mine has the identical system as me one street over with a 25° roof pitch. We compared over the last 3 years, and the yield was always a bit higher for me in winter, but higher for him in summer.

Thank you very much for the many interesting posts! I cannot see a convincing explanation for the power consumption at 4:00 AM. Why should the heating element always turn on at the same time during the night if no hot water is being used?

It’s not about hot water being used, but about keeping the water at a certain temperature. That’s probably why the heating element turns on during the night.

Thank you very much for the many interesting posts! I cannot see a convincing explanation for the power consumption around 4:00 AM. Why should the heating element always turn on at the same time at night if no hot water is being used?

But you are not doing anything at all to get an answer here. So why don’t you answer the questions asked about your generally excessive power consumption? Or about the heat pump? Or about the 5 kW peaks or higher consumptions multiple times a day? Or or or I don’t see anything special around 4 o’clock. The whole day is a peculiarity with you without further explanations.

Nice that I have sparked a lively discussion. Answering all questions seems to me to be of little help. I was only concerned with an inexplicable anomaly. The heating element always switches on only briefly, but not for hours and certainly not at night. I will present the curves to the heating engineer today. Let's see if he has an explanation. Best regards Bernd

It is also not true that a south orientation with 45° would be optimal. 100% is achieved with a south orientation at 28°.

Of course, a steeper system produces more in winter because it has a better angle to the sun at low solar elevation. Over the entire year, of course, the somewhat flatter system wins due to the higher yield in summer. And of course, the yields in December are lower than in June. This is already due to the fact that the day is 8 hours shorter. The average values, however, only poorly reflect the actual situation. In winter, there are many days where only 200W come down at noon, and some very good days where you mostly feed in.

Yields can also be very local. Saturday was top here, Sunday in the morning it still charged the storage before it clouded over again. 10km away there was still sun until the evening.

The heating element only switches on briefly, but not for hours and certainly not at night.

Go into the menu and deactivate the heating element. You really don’t need it anyway.