Additional costs equal ZERO

@Micha: Where does the money for your photovoltaic system come from? Is it just sitting in savings? Then your calculation might work. If you have to finance it, it's pointless! Oh yes, a Scottish bank offers 2.7% on TG and 4.5% on fixed deposits. You asked about that!

@Micha: Where does the money for your photovoltaic system come from? Is it saved up? Then your calculation might work. If you have to finance it, it’s worthless! Oh, and a Scottish bank offers 2.7% on the TG and 4.5% on fixed deposit. You asked about that!

Hello Perlenmann

Okay, then a little digression into mathematics :p Here: I have calculated that you can achieve a yield of 4885 euros per kWp with a photovoltaic system in the Ruhr area. >> Disclaimer: This is only an example. But a realistic one. You always have to consider each system individually!

Let’s assume the 4885 euros. Provisions are normally 1%. Availability should be >97%. The whole thing is financed by a normal loan - I leave out KfW for now. A quick internet search shows that you can currently get money at 3.75% (deviations downwards and upwards are possible). A system must not cost more than 2100 euros per kWp in 2011. I take this money at 3.75% interest. I receive 4885 euros from the state over 20 years - that is 244 euros annually. A search for a loan calculator online and using it shows that I have paid back a 2100 euro loan at 3.75% interest with an annual (!) rate of 244 euros after 10.59 years (including interest). The total cost for this was 2584 euros.

Provisions, as mentioned, should be 1% of the investment - 210 euros. Availability 97%: 4885 * 97% = 4738 euros.

So: Income: 4738 euros / Expenses 2794 euros -> 1944 euros profit

If I calculated correctly, that corresponds to a return of 3.33% p.a.

Okay, if interest rates on savings accounts rise again, you have to rethink it all. But at least the return is higher than now even on a TG account. And does your Scottish bank guarantee the interest rates for the entire 20 years? I dare to doubt that...

If you do the same calculation for Munich (approx. 980 kWh/kWp), you get a return of 4.25% - anyone can check the math themselves now :D

@Euro: Okay, then we misunderstood each other. I thought you meant general problems with photovoltaics. Problems with heat pumps and photovoltaics always occur if the system is planned incorrectly, built incorrectly, dimensioned incorrectly, or whatever. I am now assuming proper planning and installation and reasonable materials.

Best regards Micha :cool:

Hello

...@Euro: Okay, then we misunderstood each other.

That happens in the heat of the moment. ;)

(Heat pump, especially air heat pump,) + photovoltaic is basically a very sensible combination.

best regards

Hello Perlenmann

Okay, then a little detour into mathematics :p
Here:
I have calculated that in the Ruhr area you can achieve a yield of 4885 euros per kWp with a photovoltaic system.
>> Disclaimer: This is just an example. But a realistic one. You have to consider each system individually!

Let's assume the 4885 euros.
Provisions are usually 1%
Availability should be >97%.
The whole thing is financed through a normal loan - I will leave KfW out for now.
A quick internet search shows that you can currently get money at 3.75% (variations up and down are possible)
A system in 2011 must not cost more than 2100 euros per kWp.
I take this money at 3.75% interest.
I receive 4885 euros from the government over 20 years - that makes 244 euros annually.
An internet search for a loan calculator and using it shows that I have repaid a 2100 euro loan at 3.75% interest with an annual(!) rate of 244 euros after 10.59 years (including interest). The total costs for this were 2584 euros.

Provisions, as mentioned, should be 1% of the investment - 210 euros.
Availability 97%: 4885 * 97% = 4738 euros.

So: Income: 4738 euros / Expenses 2794 euros -> 1944 euros profit

If I have calculated correctly, that corresponds to a return of 3.33% p.a.

Okay, if interest on deposits rise again, then you have to reconsider all this. But at least the return is higher than what you still get on a savings account. And does your Scottish bank really guarantee the interest for the entire 20 years? I dare to doubt that...

If you do the same calculation for Munich (approx. 980 kWh/kWp) you get a return of 4.25% - everyone can recalculate that themselves :D

@Euro: Okay, then we misunderstood each other. I thought you meant problems in general with photovoltaics.
There are always problems with heat pumps and photovoltaics if the system is planned incorrectly, built incorrectly, sized incorrectly, or whatever. I now assumed proper planning and installation and reasonable materials.

Best regards
Micha :cool:

Super explained, thanks. If I ever have a similar question, I know who to ask lol

If I have calculated correctly, that corresponds to a return of 3.33% per annum.

That means anyone who has extra money and doesn’t need a loan for it would have even more return.
Strange, why is this done so little?
And who guarantees that the state will pay for 20 years?

It’s all too much for me. I don’t need to take a bigger loan in addition to the house just to maybe have some profit in 20 years.

If the numbers are correct, that would be nice... still too much risk for me.

I read up on it a bit more.
But you forget the additional costs for a meter (or are those already included in your 2100€?
You forgot the loss of yield over the term.
Are the maintenance costs supposed to be the reserves? The string inverters apparently only have a lifespan of 5-10 years.
Also, my house installment goes down if I take out additional credit.
Whether the system will last the 20 years is also unknown.
It might be that I still have mistakes in there, but I think you really have to calculate carefully here. For me (even more now) it’s too much risk.