ᐅ Is investing in a solar power system worth it? Any experiences?
Created on: 20 Feb 2009 08:07
L
LilyH
Honigkuchen20 Feb 2009 08:42Helga, please schedule a free appointment with the consumer advice center’s energy consultation.
Bring all relevant information about your house, such as its size, floor plans, energy consumption over the past years, the building materials used (including the roof), and the construction type (wood frame, solid construction, etc.). If available, also bring the different U-values for walls, ceiling, floors, roof, windows, etc., the type(s) of heating system you use, the installed systems (manufacturer, model, fuel provider, etc.), and so on.
The more details, the better.
They can then calculate whether a solar system would be worthwhile for you, or if it would be better to invest in proper insulation because that might be more beneficial.
I once saw a report about an older man who had a completely useless solar system installed. His house was poorly insulated, and the solar system wasn’t tailored to his needs. In the end, it consumed more energy than it produced, and overall was even more expensive than before.
So it really depends on your house whether a solar system makes sense.
You would also need buffer storage and things like that.
And you have to check if the sizing (how many square meters of collector area) is precisely matched to your needs.
Whether your house gets enough sun / the orientation of the collectors.
Whether flat-plate collectors or vacuum tube collectors are better.
Etc.
Unfortunately, like many things, it is very individual and extremely difficult to assess as an outsider, especially without expertise.
- I usually rely on a few old wise sayings:
“Stick to what you know,” or:
“I don’t need to know everything. I just need to know who to ask.”
All the best and good luck.
Bring all relevant information about your house, such as its size, floor plans, energy consumption over the past years, the building materials used (including the roof), and the construction type (wood frame, solid construction, etc.). If available, also bring the different U-values for walls, ceiling, floors, roof, windows, etc., the type(s) of heating system you use, the installed systems (manufacturer, model, fuel provider, etc.), and so on.
The more details, the better.
They can then calculate whether a solar system would be worthwhile for you, or if it would be better to invest in proper insulation because that might be more beneficial.
I once saw a report about an older man who had a completely useless solar system installed. His house was poorly insulated, and the solar system wasn’t tailored to his needs. In the end, it consumed more energy than it produced, and overall was even more expensive than before.
So it really depends on your house whether a solar system makes sense.
You would also need buffer storage and things like that.
And you have to check if the sizing (how many square meters of collector area) is precisely matched to your needs.
Whether your house gets enough sun / the orientation of the collectors.
Whether flat-plate collectors or vacuum tube collectors are better.
Etc.
Unfortunately, like many things, it is very individual and extremely difficult to assess as an outsider, especially without expertise.
- I usually rely on a few old wise sayings:
“Stick to what you know,” or:
“I don’t need to know everything. I just need to know who to ask.”
All the best and good luck.
H
Honigkuchen20 Feb 2009 10:32As I mentioned, I saw the report (ARD Verbrauchermarkt or something like that), and in the old gentleman’s house, the solar system was completely unsuitable.
However, you can have professionals calculate whether and what type and size of solar system would be cost-effective for you.
You should definitely have this done beforehand and not just take the seller’s word that it will pay off. After all, they just want to make a sale.
Whether you have exactly the right product, tailored in quantity, type, and location for your individual house, is something independent consultants can tell you.
Best regards
However, you can have professionals calculate whether and what type and size of solar system would be cost-effective for you.
You should definitely have this done beforehand and not just take the seller’s word that it will pay off. After all, they just want to make a sale.
Whether you have exactly the right product, tailored in quantity, type, and location for your individual house, is something independent consultants can tell you.
Best regards
Hello,
I am currently reading through the topics and came across this question.
I can only share positive experiences. When we renovated our house in 1990, a new roof was also needed, and we decided to install a solar system at the same time. We received good advice back then and have been very satisfied ever since.
Best regards
I am currently reading through the topics and came across this question.
I can only share positive experiences. When we renovated our house in 1990, a new roof was also needed, and we decided to install a solar system at the same time. We received good advice back then and have been very satisfied ever since.
Best regards
Hello,
In principle, a solar thermal system always saves energy by producing heat without burning gas or oil or using electricity. The only alternative way to achieve this is through additional insulation. Neither heat pumps, pellet boilers, nor condensing boilers can do this. So, let’s establish that a solar thermal system is always environmentally beneficial.
The other question is whether a solar thermal system makes economic sense. I would say that, unfortunately, most people install a solar system to save money rather than primarily to protect the environment.
When considering the economics of a solar thermal system, the existing building is the most important factor. If you have an older building with poor insulation and a heating system designed for high system temperatures above 50°C (122°F), investing in a solar thermal system is usually not economically viable today.
A similar situation applies to solar systems for domestic hot water only, without heating. Take a household of four people, for example, where around €300 per year are spent on hot water production. If the solar system covers about 60% of this, that equals roughly €200 in annual savings. However, the system costs between €3,000 and €4,000. With an interest rate of 5%, the annual interest alone would be about €200. This means the system does not save a single cent during the repayment period, which is likely around 30 years. Even with subsidies, it takes between 15 and 20 years before the system pays for itself. Everyone can calculate for themselves if this is worthwhile.
The situation is different for a highly insulated house with low heating demand. Today, it is possible to achieve prices for heat production using solar thermal systems that come close to those for oil or gas. This means producing 1 kWh of heat energy with a solar thermal system costs around 10-12 cents. Electricity costs between 14 and 18 cents per kWh, while gas is about 5.7 cents. Thanks to subsidies, solar thermal systems can bring the cost down to between 6 and 8 cents per kWh of heat energy produced.
However, the system must be really well designed for this. I recently came across a great saying: “Using solar thermal heat is like trying to carry water in a sieve.” Similarly, those who say “just put a solar thermal system on your roof and save money” really need to do the math.
If you install a solar thermal system today and don’t have a passive house, you should be clear that you will not save money immediately. Only once the system is fully paid off does the saving start, although the environmental benefit is immediate. Another factor is that oil and gas prices are expected to rise over the coming years, just as they doubled in the past 10 years, which will change the calculation significantly.
In principle, a solar thermal system always saves energy by producing heat without burning gas or oil or using electricity. The only alternative way to achieve this is through additional insulation. Neither heat pumps, pellet boilers, nor condensing boilers can do this. So, let’s establish that a solar thermal system is always environmentally beneficial.
The other question is whether a solar thermal system makes economic sense. I would say that, unfortunately, most people install a solar system to save money rather than primarily to protect the environment.
When considering the economics of a solar thermal system, the existing building is the most important factor. If you have an older building with poor insulation and a heating system designed for high system temperatures above 50°C (122°F), investing in a solar thermal system is usually not economically viable today.
A similar situation applies to solar systems for domestic hot water only, without heating. Take a household of four people, for example, where around €300 per year are spent on hot water production. If the solar system covers about 60% of this, that equals roughly €200 in annual savings. However, the system costs between €3,000 and €4,000. With an interest rate of 5%, the annual interest alone would be about €200. This means the system does not save a single cent during the repayment period, which is likely around 30 years. Even with subsidies, it takes between 15 and 20 years before the system pays for itself. Everyone can calculate for themselves if this is worthwhile.
The situation is different for a highly insulated house with low heating demand. Today, it is possible to achieve prices for heat production using solar thermal systems that come close to those for oil or gas. This means producing 1 kWh of heat energy with a solar thermal system costs around 10-12 cents. Electricity costs between 14 and 18 cents per kWh, while gas is about 5.7 cents. Thanks to subsidies, solar thermal systems can bring the cost down to between 6 and 8 cents per kWh of heat energy produced.
However, the system must be really well designed for this. I recently came across a great saying: “Using solar thermal heat is like trying to carry water in a sieve.” Similarly, those who say “just put a solar thermal system on your roof and save money” really need to do the math.
If you install a solar thermal system today and don’t have a passive house, you should be clear that you will not save money immediately. Only once the system is fully paid off does the saving start, although the environmental benefit is immediate. Another factor is that oil and gas prices are expected to rise over the coming years, just as they doubled in the past 10 years, which will change the calculation significantly.
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