ᐅ Photovoltaic Systems: Advantages, Disadvantages, Experiences, and Is It Worthwhile?

Bau_Bambi schrieb:
Or a photovoltaic system on three roof sides without changing the size of the system? Does this make sense in terms of effort if you stay under 10 kWp?

I can confirm this from my own experience. Our system produced a nice, even output from morning to evening (it was somewhere between 7 and 8 kWp).

Three orientations are not ideal because common inverters usually only support two strings, and one string is needed per orientation.
The efficiency loss due to heat is not that significant. Typically, modules lose about 4% of their output for every 10°C (18°F) increase in temperature.
Ultimately, you have to work with the existing roof anyway. If you can position the system freely, you can, of course, optimize it. It’s best to experiment with tools like PVGIS.
Module prices have dropped significantly recently, which reduces the disadvantage of east/west systems even further.

Bau_Bambi schrieb:
Or is it possible to have a photovoltaic system installed on three roof sides without changing the system size? Does this make sense effort-wise if you stay under 10 kWp?

As mentioned, you always have to check what the inverter supports.
We have a bungalow with a 35° roof pitch facing southeast and southwest, so rotated by 90°. The roof covering will need to be replaced in the next few years anyway. At that time, we plan to install a few kW of modules on both roof surfaces. The installation itself is not that difficult, but connecting to the grid requires an electrician.

We have a 45° gable roof with an east(south)/west(north) orientation... but it’s slightly rotated, so the east side has twice the number of panels.
I also try to make sure the washing machine and dishwasher run when there is enough steam, but without overdoing it.

The total consumption for 3 people in 2018 was just under 2300 kWh... but I generated half of that myself.

I just checked again. Out of 2100 kWh consumed in 2018, we generated about 900 ourselves. So roughly 42%. However, 2018 was also a very good year...

dertill schrieb:

We have an L-shaped bungalow with a 35° (35°) roof pitch facing southeast and southwest, so rotated 90°. The roof covering will need to be replaced in the next few years anyway.

That sounds like a great roof for photovoltaic panels!