Is a solar power system worth it? Experiences?

Hello dear forum,

we could have a solar system installed on the roof, the costs would be around 6000 euros. Now we are wondering if we can ever get that back. Does the system even last that long?

Regards

Helga, please make a free appointment with the energy consultation service of the Verbraucherzentrale.
Take all the data about your house with you, such as size, floor plans, how the consumption has been in recent years, what materials it was built from (also the roof) and how (wood construction, solid, etc.), if you have them, also the different U-values for walls, ceiling, floors, roof, windows, etc., what type(s) of heating you use, what systems are installed (which manufacturer, which model, which supplier for the heating fuel, etc.), and so on and so forth.

The more info the better.

Then they can calculate for you whether a solar system makes sense for you, or if you should better invest the money in good insulation, because that would benefit you more.

I once saw a report about an older man who was given a solar system that was totally useless for him because he had a poorly insulated house, and the solar system was not tailored to him, and in the end it consumed more than it produced; I believe it was overall even more expensive than before.

So it really depends on your house whether a solar system is worth it for you.
You will also need a buffer tank and such.
And you have to check whether the sizing (how many m² of collector area) is exactly tailored to you.

Whether your house gets enough sun / the orientation of the collectors.

Whether flat collectors or vacuum tube collectors are better.

Etc.

Unfortunately, like many things, it is individual and very difficult to assess as an outsider and especially as a layperson.

- I handle it with a few wise old sayings:
"Shoe maker, stick to your last" or also:
"I don't have to know everything. I just have to know who I can ask."

All the best and good luck

As I said, I had seen the report (ARD Verbrauchermarkt or whatever it's called or something), and in the old house of the old gentleman, the solar system was totally off. You can have professionals calculate whether or not, and what type and size and such of a solar system would be profitable for you. You should definitely have that done beforehand, and not just blindly believe the seller when they say it pays off. After all, they just want to make a sale. And whether you have exactly the right product, tailored in quantity, type, and location for your individual little house, that is something independent consultants can tell you. Regards

Hello,

I am currently reading through the topics and came across this question. So I can only report positive things. When we renovated our house in 1990, a new roof was also due, and we immediately decided on a solar system; we were well advised back then and have been very satisfied ever since.

Best regards

Is a solar system also worth it?

Actually very slowly, with 100 to 200 euros per year for solar thermal energy. That means almost all other reasonable measures pay off faster.

Best regards

Hello,

basically, you always save energy with a solar system, i.e. you generate heat without burning gas or oil or using electricity. The only way to achieve this differently is with additional insulation. Neither heat pumps, pellet heating systems, nor condensing boilers are capable of this. So let's establish that a solar system is always environmentally sensible.

The other question is whether a solar system is economically sensible. I would say, unfortunately, most people install a solar system to save money and not necessarily to protect the environment.

When considering the economics of a solar system, the existing building is the primary focus. If I have an old building, poorly insulated, with a heating system designed for high system temperatures above 50 degrees, a solar system is pointless; at least today, it will not operate economically.

It is similar with solar systems for hot water only, i.e. without heating. Let's take a household of 4 people; it costs about €300 per year to generate the hot water. I cover 60% of that with the solar system, so let's say about €200 savings per year. However, the system costs me between €3000 and €4000. Just the interest per year (at 5%) amounts to about €200. That means this system doesn't save a single cent; I actually lose money because the system also needs to be paid off, presumably over 30 years. Even when considering subsidies, it takes between 15 and 20 years for the system to pay off. Everyone can calculate for themselves whether it is worthwhile.

The case is different with a highly insulated house with low heating demands. Today it is possible to achieve prices for generating heat energy through solar systems that approach those of oil or gas. That means producing 1 kWh of heat energy with a solar system currently costs me about 10-12 cents. Electricity costs between 14 and 18 cents, gas about 5.7 cents. Due to subsidies on solar systems, I can get into a range of 6-8 cents for generating 1 kWh of heat energy.

However, the system must be really well designed; I recently read a nice saying: "Wanting to use solar heat is like trying to get water with a sieve." It’s the same with all those who say, just build a solar system on the roof and save money—they really should do the math.

If you install a solar system today and don't happen to have a passive house, then you should be clear about one thing: you don't save money. Only after the system is completely paid off does the saving start; the effect on the environment is, of course, immediate. Moreover, if prices for oil and gas continue to rise in the coming years as they have in the past 10 years (they have doubled), the calculation looks completely different.