Solar system, yes or no?

Direction towards midday sun i.e. south. Depending on the longitude, a different inclination is necessary. I read somewhere about approx. 30° inclination. However, that depends on the location. Smaller deviations should not be a big deal. With southeast or southwest orientation, 90% should still be possible.

Hello

Unfortunately, here both photovoltaic (Photovoltaic) and solar thermal system (Solarthermie) are talked about all the time. Both must please be distinguished!

Photovoltaic:
- Optimal orientation as exact south as possible. Rather a few degrees towards east deviation (5°-10°). The modules work best when they are cold - i.e. it’s better to catch a little more morning sun than evening sun, when the modules have warmed up during the day.
- Optimal inclination in Germany: At noon, the sun is at 62° above the horizon in summer, about 16° above the horizon in winter. That means a flatter mounting takes in more summer sun, steeper more winter sun. The 30° is a common compromise between summer and winter. But other inclinations over the year do not make much difference in yield.
- Financially: This must be calculated on a case-by-case basis. Two years ago, a private builder could still achieve 12-13% return over 20 years (duration of the government guaranteed feed-in tariff) - and really, not just on paper. Currently, realistically about 3-4% should be achievable if the system is properly planned...
With self-consumption during the day (a parent with children home all day, home office, ...) a higher return is also possible.

Whether a photovoltaic system is worthwhile must - surprise surprise - be calculated by a specialist on a case-by-case basis

Solar thermal system:
- Orientation and inclination should correspond analogously to photovoltaic - maybe optimal orientation here is more towards west, since I want to take the heat...

- Regarding profitability: How long does the temperature hold in the hot water storage tanks? As well insulated as they are today, I would guess about 12-14 hours. That means in summer I can still have the whole family shower/bath in the evening with water from the solar thermal system.
And there should still be warm shower water left until the next morning.
In winter (assuming good weather) the hot water tank should also be warm enough for me to cover my needs in the evening.
Furthermore, I also connect my dishwasher and washing machine to the hot water. It’s stupid if I continue to heat water for these appliances electrically, geothermal and next to the tank let it cool down unused...

Personally, I have only heard good things from acquaintances who have a solar thermal system. Nobody is unhappy with it...

I will definitely get one - then in 2-3 years I can draw a conclusion here

So much for my 10 cents
Micha

...Personally, I have only heard good things from acquaintances who have a solar thermal system. None of them are dissatisfied...

That is satisfactory after all Maybe instead of general satisfaction, there are also concrete data? How many kWh were actually harvested with which system and which installed heat meter?

Best regards

Hello €uro

I haven't asked in detail yet...
I have to do that sometime, and then I can answer your question

Regards
Micha

Hello

Unfortunately, here both photovoltaic (photovoltaic) and solar thermal system (solar thermal) are continuously being talked about.
Both must please be kept separate!

Solar thermal system:

- Regarding economic efficiency: How long does the temperature in the hot water storage tanks last? Given how well insulated they are these days, I would roughly guess 12-14 hours.

In winter (assuming good weather, of course) the hot water tank should also be warm enough so that I can still cover my needs in the evening.
Also, I connect my dishwasher and washing machine to the hot water supply. It’s stupid to continue heating water electrically for these devices while letting the hot water tank cool down unused...

That’s my two cents
Micha

Hello!

I have only had my solar system for a few weeks now. The temperature in the 300 l tank naturally drops continuously without sunlight and is not maintained. I see no problem with that in winter; it works as a heating support, so to speak.

From my first impression, the energy is sufficient for several days, as the water is heated well above shower temperature. I’m still not completely happy with the system control. When 300 liters of water in the tank have been heated to 45 degrees, theoretically four people could shower with it. But apparently, water taken out is immediately replaced again with (cold) water. This means the first person showers hot, the second warm, the third lukewarm, and the fourth better not at all. I hope there is some way to adjust this!?

Connecting electrical appliances is an interesting idea—I’m just not sure if the electronic controls of the washing machine and co. can handle that. Also: if the solar water is really hot, you have to supply the machine with water for shirts, etc., via a mixing valve!?

By the way, my neighbor has a 210 l tank, which occupies the rather unused space under the boiler. Compared to that, the 300 l tank (maybe due to stronger insulation) seems huge—and hinders the use of the utility room.

Best regards,
Tomtom.

...At least in winter I don’t see a problem, it works basically as heating support.

How would that be possible???

...But apparently the withdrawn water is immediately (cold) supplied again.

Well, there seem to be considerable deficiencies here! What temperature level should the replenished domestic hot water have?

...From my first impression, the energy is sufficient for several days, since the water is heated far above shower temperature.

"Temperature" is something completely different from energy!!! Surely no heat meter was installed here, otherwise the conclusions would be completely different!

...I am not yet happy with the control of the system..... I hope it can be set differently somehow!?

Well, then good luck!

regards

How would that be possible???
Well, there seem to be significant deficiencies here! What temperature level should the replenished BW have?
"Temperature" is something completely different from energy!!! Certainly, no heat meter was installed here, otherwise the conclusions would be completely different!
Well, then good luck!

v.g.

Hi!

Euro got me on this – energy consultant vs. homeowner!
Question 1: Law of conservation of energy.
Question 2: Wrong way of thinking. First "use up" heated water, then replenish.
Statement about temperature and energy: I have never thought about that before – but it sounds like nonsense.
Heat meter: At most it was installed here without my knowledge – do you mean the TV transmitter or the washing machine control center?

Ah, I love KS and FI.

Cheers,
Tomtom.