Flat collector vs tube collector

I do not want to start a fundamental discussion with technical comparisons here, but only want to ask my question resulting from laziness ... (researching is very extensive - and the more you inform yourself, the more complicated it becomes). I have already looked at the companies' documents and found that the type tube vacuum collector is in a higher price segment than the conventional flat plate collector. Regarding the technical performance data, I have the impression that I need to take up studying again. To explain: I want to initially try with one collector in self-installation to see how much hot water I can produce. Then multiplying that and realizing it in a large installation for real, and calculating beforehand what the fun would cost me, should not be a problem. I am quite skeptical about the amortization calculations discovered so far as a potential skeptic. (- Regarding photovoltaic consideration, I have already thrown in the towel for that reason.) My problem is that the gable roof slope faces FULLY west. Does that even bring enough to make it worthwhile? The tube collector is supposed to be better in this respect in the effective range because it can better utilize side radiation as well. But when I see the efficiencies stated by the companies, I notice that the companies act as if one system is boiling and the other is almost cooling with differences of about 7% ;-) Does anyone have experience whether the better side sensitivity actually yields significantly more? The flat collector is certainly simpler in the long run than the tubes, where I see that they are also offered as spare parts ?! - for me, the question is why? Does the vacuum deteriorate? After what time? Even if it is an experiment, I would prefer not to create two test setups. Thanks in advance for a tip, a believer in the sense of collective intelligence. ;-)

Large-scale assembly, amortization, trial self-assembly? What are you actually planning?

You are building and have to or want to install ST on the roof, for hot water generation or heating support, or want to retrofit?

As a rule, ST is never economically viable compared to photovoltaics, but is the lesser economic evil to get the gas heating through.

If your gable roof faces fully west, then you also have an east side and I would cover both sides with photovoltaics.

Sorry for the poor description of my planning. I do not want to build, but have a house in which everything works. Within the framework of environmental considerations as well as cost-saving measures, I see many upgraded roofs, from which my thought results that I should also behave a little future-oriented. Like many, I noticed just this summer while using my garden hose that the sun provides quite a bit of energy. Since I, as a dedicated DIYer, have some experience in all trades, I want to set up a collector, couple it with a storage tank, and test on various sunny days to what extent and in what quantity my shower water can be produced more cheaply. If this leads to a positive result, I can install a larger system completely on my roof. Unfortunately, I do not have a south-facing orientation available for installation, which is why I am skeptical whether the effort is really worthwhile. Manufacturers and installation companies naturally always take the position that it would be worthwhile, even if only a cup of warm coffee is produced in the end. I have found that the saying (Versuch macht Kluch) is often true. For example, with my heating, I found that "turning it off" has the biggest saving effect, which was disputed by all professional companies. In summer, my heating (oil) is off and I shower electrically. Regarding the collector, I am therefore considering whether it is worth investing a little more in the experiment (tube collector), since its performance could somewhat compensate for my west orientation. I could try using two different collectors (flat and tube) experimentally, but for such an experiment I did not want to invest so much after all, since if the experiment does not meet my expectations, no one will buy the unused collector from me. (Maybe that is an idea after all – I have to check on eBay). First of all, greetings and good night :-)

East-west orientation is nice for a photovoltaic system with a high self-consumption rate. Personally, I would consider it more than [ST]. Honestly, I wouldn’t even think about [ST] at all ;-)

You seriously want to hang solar panels around his neck in the old building with an oil heating system?!

You seriously want to hang solar panels around his neck in an old building with an oil heating system?!

What does the type of heating have to do with photovoltaics? Even with the current feed-in tariff and well-planned self-consumption, a reasonably planned photovoltaic system, which is not necessarily sold by an exploitative dealer, pays off after 7-10 years. When at ST? Will the OP still experience that?