ᐅ Solar / Photovoltaics from an Economic Perspective

DaLinux schrieb:
How would it behave if the solar thermal system is also connected to the underfloor heating?
It won’t have any effect in winter. But it should cover the transitional seasons.

You would need at least 2 additional panels and a larger buffer storage tank, which would increase the costs. Also, in winter, you would have to heat the large buffer storage with gas.

This is how it looks... during the transitional season, hardly any yields can be expected... in winter, none at all...

Mycraft schrieb:
This is how it looks...during the transitional seasons, hardly any yield can be expected...in winter, none at all...

I think the concept needs to be adjusted then. The system should not be optimized for the summer but rather for the transitional seasons or winter. This means, for example, solar panels are installed at a steeper angle to capture the optimal angle of the low sun and to be as snow-free as possible. (See "Sonnenhaus"). Whether this will eventually pay off, I have no idea.

alexm86 schrieb:
The efficiency of the system decreases over the years, ....

Mycraft schrieb:
That’s what I mean... and the fact that the inverter and the panels are likely due for replacement after just over 10 years is almost certain... there are plenty of examples

Hmm – manufacturers usually provide a 20 to 25-year performance warranty for the modules. To my knowledge, this is based on an annual percentage degradation rate. I would have to check my documents, but I seem to recall that the total reduction over 20 years is at most 20%. Therefore, a module failure as described by @Mycraft should qualify as a warranty case – although I don’t currently have the exact terms on hand (and you probably don’t either).

By the way: damages that require replacement can always occur. Whether they actually happen and how severe they are depends on how the product is handled and, of course, on sheer chance.

At least we have successfully passed the first year. Let’s see, maybe in 9 years I will report back on the condition and whether parts of the system need to be scrapped.

Well, unfortunately the warranty is of little to no use because most manufacturers have filed for bankruptcy after 5-6 years... Therefore, you only get the legally required 2 years of statutory warranty, no more and no less...

Mycraft schrieb:
Well, the warranty is unfortunately worth little to nothing since most manufacturers declare bankruptcy after 5–6 years... So you end up with no more and no less than the legally required 2-year statutory warranty...

In that case, I’m glad my manufacturer (Viessmann) is still active and does not have its core business in the photovoltaic sector. That means there’s a chance I could still benefit from the 25-year warranty in the worst-case scenario.