Consultation for photovoltaic systems

Cool, numbers! Thanks! :-)
You can definitely address this concretely.

At 7000 full cycles, you can just do a simple calculation for 1 kWh battery capacity:

1 kWh storage is very unusual; the electronics (converter, balancer, etc.) are significantly more expensive in relation to the capacity.

7000 * 0.9 kWh (on average 90% of the battery capacity) * €0.3/kWh (assumed average electricity price over the lifetime) = €1890

Even if you charge and discharge the battery once a day, that would be 20 years.
I find that quite optimistic, but well, not impossible.

The next problem is that the lost feed-in tariff is missing here.
Therefore, only about 20 cents remain.

Let’s calculate with 200 cycles per year and €0.35/kWh average price over 10 years
2000 * 0.9 * 0.35 = €777

Already starting with a miscalculation:
2000 * 0.9 * 0.35 = €777 €630
Also, the lost feed-in tariff is again missing here, and why is electricity now 5 cents more expensive?
So halfway correctly:
2000 * 0.9 * 0.20 = €360

A net kilowatt-hour battery costs between €400 and €500 in the private customer sector today.

Including electronics, inverter, etc.?
That would be nice!
And still significantly more expensive than the €360 above.

Somehow, people seem to want storage.

I wonder why that is?

My conclusion: There are some significantly more rewarding investments and at the same time a ton of significantly worse purchases.

I can basically agree with that. Especially subsidies shift the calculation.

However, justifying the ecological meaningfulness is even much harder.

And of course, just like with the inverters, the purchase of a second storage device should be factored in within the 20-year balance sheet. Not because the cells break down. The electronics often say goodbye much earlier. And no, no one has to do the math. There are easily findable studies on the topic. All of them come to the same conclusion: storage is an expensive hobby. But hey - I don’t want to stop anyone from having a storage/hobby. AS LONG AS the storage is not used as a (financial) excuse for why the roof wasn’t fully outfitted. Because that is what the world really urgently needs: a lot more photovoltaics.

Instead of buying expensive electricity, I prefer to use cheap photovoltaic electricity and SAVE. Everything I don’t use, I sell. Nice setup. But in the first step, you actually spend money, which you get back after a few years.

And exactly this calculation I would like to see. About the storage: what do you want with 1 kWh, please? If storage, then please so that I am largely self-sufficient even in winter – otherwise I haven’t achieved anything. And currently, that does not work without a “fat wallet.” And until these investments have “sun-paid” for themselves, how many leap years have passed?

One can address that concretely.

... and doesn't have to contribute anything himself...

1kwh storage is very unusual, there the electronics (converter, balancer, etc.) are also significantly more expensive in relation to the capacity.

once again a not wanting to understand will - per 1kW you can multiply.

miscalculated:
2000 * 0.9 * 0.35 = 777€ 630€

Thanks for the correction.

In addition, the lost feed-in tariff is also missing here again

Offsetting the feed-in tariff - right, you can include that in the electricity price - however you estimate it for the next 10 years. Currently around 7ct/kWh.

In addition, the lost feed-in tariff is also missing here again and why has electricity become 5 cents more expensive now?

once again not wanting to understand, if you change the parameters, you can also change the electricity price forecast for the next 10 years. You can also calculate with falling prices or a strong increase. Guesswork remains guesswork.

What could be the reason for that?

That would have been your contribution for an answer. Shame, again no substance.

Because that is what the world really urgently needs: Much, much more photovoltaics.

Strongly agree.

If battery storage, then please in such a way that I am largely self-sufficient even in winter – otherwise I couldn’t do anything. And currently that just doesn’t work without a "fat wallet." And until these investments have been "re-sunned," how many leap years will have passed?

In winter, you usually don’t fill your battery anyway (with the typical 7-10kWp systems). If you have a heat pump, it already consumes all the generated electricity. That’s why a small 1kWh battery is actually a great thing, because it covers the base load. So refrigerator, ventilation, etc. With that, you can really manage the cycles you need for it to pay off.

... and doesn’t have to contribute anything himself...

Feel free to look at my profile; I have already posted many numbers, facts, and example calculations here. Belief and pure assertions are rather rare with me. ;-)

once again a refusal to want to understand – you can multiply by 1kW each.

Unfortunately not. Other variables change the calculation very much, completely different cycles, prices, etc. As written above, a 1kWh battery definitely has its appeal if it were available.

Offset feed-in tariff – true, you can factor that into the electricity price – however you estimate it for the next 10 years. Currently around 7ct/kWh.

I am more in favor of calculating with currently available figures. Electricity cost 28 cents and remuneration of 8 cents is real, as of today. Everything else is crystal ball.

That would have been your effort for an answer. Too bad, no substance again.

So here are a few possible reasons (even though you already find the real substance and correct numbers above): a) calculations are often done incorrectly/not done at all/belief is given to wrong calculations of sellers b) people believe in "self-sufficiency" and "their own electricity," even though most systems are not island-capable, sometimes only single-phase, etc. is often forgotten c) it is subsidized d) people believe, for whatever reason, in sharply rising electricity prices The list can gladly be extended.

If storage, then please in a way that I am largely self-sufficient even in winter

Yes, I would really like to have that too.