Solar system despite shade in winter?

Hello everyone,

I am planning to build a house this year and am currently dealing with the heating system and would like to hear some opinions from you.

I already had an appointment with our local energy consultant from the city on this topic. Together with him, we came to a similar conclusion as I had beforehand: a heat pump with geothermal drilling.
Another point in this conversation was a solar system on the roof (initially independent of solar thermal or photovoltaics). Since our roof is almost exactly south-facing, that sounds very tempting at first. The energy consultant also recommended it under these circumstances.

However, I have two points that still give me headaches: In a model calculation with the energy consultant, we assumed a required heat amount of about 10,000 kWh for our KfW70 house. With an annual performance factor of 4, that amounts to 2,500 kWh of energy per year, or about 210 kWh per month. Assuming that mostly night-time electricity (assumed price 14 cents/kWh) can be used, the monthly costs come to roughly €30.
Here the saving potential I have through a solar system (especially solar thermal) seems very low to me. With a system costing €3,000, I would already have to heat exclusively with my solar system for 100 months for it to pay off. That could take ages...
The second point that comes in is the fact that I recently found out that the roof is mostly in the shade during winter - the neighboring house is too tall. Even at noon, no sun is expected to shine on the roof, as it is too low. Direct sunlight is primarily expected in the morning.

I wonder whether a solar system makes sense under these circumstances and would be happy to hear some assessments from your side. I have not talked about this with the energy consultant again yet, but that is still planned.

I look forward to your feedback!

Best regards
Hügel

Hello Hügel,

in my experience, solar thermal is not worthwhile with a heat pump. We always recommend a photovoltaic system that feeds excess electricity into the grid. I don't know what the current subsidies are, but photovoltaic systems have paid off after just a few years (also due to the subsidies).

best regards

K.Brodbeck

I would contact an independent energy consultant again. One from the city might also be willing to advise in favor of the [Stadtwerke] :D