Photovoltaic system – is it worth it?

100% construction loans for 10 years are currently at 1.5 - 1.7%.

Consumers currently do not even pay >5% for consumer loans. The condition you mentioned is in the range of overdraft interest rates. Of course, no one does that.

Class I is for the local commercial pub, but has nothing to do with the creditworthiness of consumers.

Be that as it may, ultimately that is not the point at all. The question was whether photovoltaic is worthwhile and the clear answer is YES. The attempt to argue using some horror financing is unsuitable. Because in the end, you can also get such a system installed without your own liquidity (lease/rent).

Anyway, that's not the point at all. The question was whether photovoltaics are worthwhile, and the clear answer is YES.

I financed my photovoltaics through a long-term private loan. And there were no horror interest rates above 3%. A construction loan would have been even cheaper... Otherwise, the OP apparently comes from Austria, and AFAIK the interest rates there are significantly higher than here. But maybe the OP can finance it through a German bank. Regards Nika

Be that as it may, ultimately that is not the point at all. The question was whether photovoltaics are worthwhile and the clear answer is YES.

I see it the same way – important: the calculation looks different in Germany and Austria. Please check yourself.
Tip: Even if no storage battery is to be used from the beginning, when buying, make sure to choose a hybrid inverter that can ideally control a battery later on the DC side.