Evaluation of photovoltaic system offer with storage

A first estimate with pvgis results in 950 kWh on SO and 680 on NW per kWp and year.

For more precise values, one would need the region, the exact rotation angle of the house (I looked at 50 degrees), and the region where the house is located.

But one can already see that SO should definitely be fully covered, so it needs to be checked whether one more row will fit.
NW, on the other hand, will hardly be worth it.
It would have to be about 30 percent cheaper than SO.

So, again, offers for SO as fully covered as possible and SO+NW fully covered?

A first estimate with pvgis results in 950 kWh on SE and 680 on NW per kWp and year.

For more precise values, you would still need the region, the exact rotation angle of the house (I looked at 50 degrees), and the region where the house is located.

But you can already see that SE should definitely be fully utilized, so it should be checked whether another row can still fit.
NW, on the other hand, will hardly be worth it.
It would have to be about 30 percent cheaper than SE.

So again, offers for SE as fully covered as possible and SE+NW fully covered?

Hello RotorMotor.
Thank you for your help. I don’t have the exact rotation angle, but I think according to the open space plan we should be roughly at 50 degrees. We are located in the Marburg-Biedenkopf district. Since we have a nice view, the sun shines more or less undisturbed, it only sets behind a forest about 100m away in the evening.
I will request the offer again with more panels. What I am still wondering: does it still make sense to have some modules on NW to have some electricity for self-consumption in the evening, even if it is less effective? I think that after work there is still somewhat more electricity needed and depending on the season the sun already disappears from the SE side then.

Many greetings

Hello RotorMotor.
Thanks for your help. I don’t have the exact angle of rotation, but I think according to the free space plan we should be roughly around 50. We are located in the Marburg-Biedenkopf district. Since we have a nice view, the sun shines more or less undisturbed, only setting behind a forest about 100m away in the evening.

Then my estimates should be pretty accurate.

I will request the offer again with more panels. What I’m still wondering: do some modules facing NW still make sense to have a bit more power in the evening for self-consumption, even if less effective?

I suspect that overall it’s not really worth putting just a few panels facing north.
Because you would reduce the yield by about 20%.
Whether this lower yield can then be compensated by higher self-consumption is questionable, but not impossible.
But you can also simulate this with pvgis. Simply set it to daily data and try the different angles for different months.

Once again.

You can calculate however you want, but after 4 weeks at the latest, you will be very annoyed that you built a photovoltaic system without storage.

Namely when your electricity meter starts to turn and you have to draw the expensive electricity from the grid.

And I tell you, your annoyance about this will begin after just a few days. Also because in the rarest cases the calculations then match the actual yield.

For a pure feed-in system to be worthwhile, you have to go over 30 kWp.
Everything else is just playing around.

And if the electricity price rises to 60 cents and more in a few years and everyone is screaming for storage, then do you want to retrofit?

But feel free to listen to all the nonsense talkers and leave out the storage. I have one and I am happy with it. But you will still remember my words.

You can calculate however you want, but after 4 weeks at the latest you will be very annoyed that you built a photovoltaic system without storage. Namely when your electricity meter starts to turn and you have to draw expensive electricity from the grid.

Electricity meters no longer turn. So there is no need to be annoyed.

For a pure feed-in system to be worthwhile, you have to go over 30 kWp. Everything else is child's play.

More is always better, but there are no limits drawn by you. Child's play is rather your storage.

But go ahead and listen to all the nonsense talkers and leave out the storage. I have one and I am happy with it. But you will think about my words later.

Yes, better not listen to those who come to me with formulas, simulations, calculations. Better are the gut feelings of emotional people who strictly refuse to publish a few numbers about their own system. But nice that you are happy!

So, as I have heard, there are currently massive delivery difficulties for the digital electricity meters, which exclusively come from China. Many photovoltaic systems are therefore not yet operational or have long waiting times for commissioning. There are still plenty of analog electricity meters spinning around. We are just a high-tech country.

Can you actually simulate the weather? Three weeks of fog or sunshine in November are very close to each other. Often only a few kilometers apart.

With only a few centimeters of snow on the modules, the yield is zero. And ask photovoltaic owners about the actual yield in August 2023 and the forecasts for it.