ᐅ Solar Power System: Yes or No?

€uro schrieb:
Hello,

That assumption is incorrect because these heat pumps "draw" energy from the space where they are installed. Where do you think that energy comes from? Just have an energy balance calculated. Additionally, the coefficient of performance (COP) hardly exceeds a value of 2. "Standard" air-source heat pumps reach > 3.5!

Best regards.

I have such a unit in my basement. It runs from April to October. During this period, I don’t need a single drop of oil. The electricity cost is almost exactly 10 euros per month.
So, it doesn’t actually draw energy from the installation space. In winter, it doesn’t run at all.
The purchase cost was about 3,500 euros.
My heating oil consumption has decreased significantly because of it.
A solar system costs many times more and usually only provides hot water when I don’t need it.

Regards

€uro schrieb:
Hello,
In my opinion, solar systems is the general term and includes solar thermal systems as well as photovoltaic systems.

Best regards.

That's correct. However, Matze66 was clearly referring to a photovoltaic system – which is not the subject here at all.

Regards

S.D. schrieb:
The electricity cost is almost exactly 10 Euro per month.

Using € as a unit for energy is somewhat unclear.

With a COP of 2 and a price of €0.20/kWh, one can estimate a thermal energy demand of 100 kWh per month. With a modern gas condensing boiler at €0.05/kWh, this would amount to €6.25 per month, while a real air source heat pump would be around €5.7 to €6.6 per month. An older oil boiler at €0.06/kWh would result in about €12 per month.

The latter shows a difference of €2 per month compared to the exhaust air heat pump. With 7 months of use per year, this results in savings of €14 per year on an investment of €3,500.

A truly worthwhile investment.

Best regards.

S.D. schrieb:
I have one of these units in my basement. It runs from April to October. During that period, I don’t use a single drop of heating oil. The electricity cost is almost exactly 10 euros per month.
So it doesn’t draw energy from the installation room. It doesn’t run in winter anyway.
The initial cost was around 3,500 euros.
My heating oil consumption has clearly dropped because of it.
A solar system costs many times more and usually only provides hot water when I don’t need it.

Regards

Thank you for this opinion! I also installed a system for hot water at my parents’ place. And their gas consumption went down – what more could you want!
CO2 saved, gas saved, and they are happy! That’s been the case for 10 years now. The system cost 5,000.00 DM back then, minus subsidies.
I would recommend it to you; BAFA still offers good grants until the end of this year!

@Pendel: Yes, I have had exactly the same experiences. According to the manufacturer, the coefficient of performance (COP) is over 3. According to "€uro," it is only "2."

Regards

Hi,

May I jump in here? I guess a new post wouldn’t follow the forum rules anyway.

So: I haven’t quite understood how solar systems can be used. Are they just for hot water? Or can they also produce electricity for household appliances?

For hot water, it wouldn’t really be necessary for us. During the day, hardly anyone is at home, and so far the 7-liter (2-gallon) storage in our boiler has been enough for washing hands after using the toilet. Up to now, we have a boiler with an instantaneous water heater.

But the monthly electricity costs for appliances, PCs, etc. are quite high.
The new house would be detached and would always have sunlight. There are no trees blocking it either. But it will likely have a pitched roof. Which way should the roof face then? East? Directly south? I can still plan all of this...
Most of all, I’d like to know what kind of system is needed. Based on brand and size, I can then research or ask more specifically. Maybe someone also knows what the costs are. We have an annual electricity consumption of around 5000 kWh (this will increase since I now have my home office).

Thanks for the food for thought.

Regards, Bromi