ᐅ Photovoltaic System: Costs and Savings Potential – Experiences?

You don’t usually arrange this through the general contractor but look for the best offer yourself. In January, we paid a total of €12,000 gross for a 9.2 kWp system including the Home Manager.

kati1337 schrieb:

That’s even less cost-effective because, although we have more panels on the roof, our self-consumption rate decreases. It only becomes really profitable if you use as much of the generated electricity yourself and feed as little as possible back into the grid.
But that’s not so easy, unless you consider a combined heat and power unit (CHP) or a battery, which would make the system disproportionately more expensive again, so it wouldn’t pay off at all.

That is not quite correct either.

guckuck2 schrieb:

- First mistake already in household electricity consumption. Where are 4000+2800+400 = 8000?

My mistake, I was juggling the numbers a bit in Excel and added a buffer on top (I assumed 400 for air conditioning was a bit underestimated). But I didn’t update the basis of my assumption above; that was just a note to myself. The calculation is only done with the value stated below (8000).

guckuck2 schrieb:

- Electricity price for 2020 is 0.26 cents, four columns to the right shows 0.24 usage price. Huh?

The beige-highlighted figure was a specific offer I had calculated. The “electricity price approx.” is calculated from the details in the offer and includes the base price per month. 0.24 is only the usage price. My total costs consist of usage price plus base price, so that needs to be taken into account.

guckuck2 schrieb:

- Acquisition cost of €9280 for 4.2 kWp is absolutely overpriced (biggest incorrect assumption in the calculation in my opinion). The system should cost around €4600-4800 net. Or is a battery included that is ruining the balance?

No, that’s a gross price, but as it is. It was already included in the first offer from the general contractor and we were quite worried at that time and wanted everything from one source.

guckuck2 schrieb:

- The photovoltaic system is simply too small for household consumption. The share of self-consumption is probably quite high, making a battery particularly uneconomical if applied.

Not planned—we have a battery included in other calculations in the table, but as you say, that’s even less economical.

guckuck2 schrieb:

- All taxes have been forgotten. In the case of self-consumption, VAT is missing, which negatively affects profitability. On the other hand, this only applies for 5 years (then reduced VAT rate). Depreciation also works in the other direction but is ignored (especially with such a high system price).

It’s also mentioned in the original post that I did not consider taxes because I didn’t know how to include that in the Excel sheet. Plus, I didn’t know VAT applies for self-consumption? I thought it was only for feed-in?

kati1337 schrieb:

Is it correct that VAT applies to self-consumption? I thought it only applied to feeding electricity into the grid?

VAT is actually even higher for self-consumption. You also have to include the imputed income you gain in your profit and loss statement and pay taxes on the profit.

But that doesn’t help much—the mistake is in the initial purchase itself. However, everyone else has already pointed that out. Then your calculation would look a lot better.

nordanney schrieb:

For self-consumption, even more applies. You also have to include the monetary benefit you gain in your income-surplus calculation and pay tax on the profit.

But that doesn’t help, the mistake is in the initial purchase itself. But everyone else has already said that. Then your calculation would also look a lot better.

That’s true. But now the damage is done. Nevertheless, we are looking forward to the photovoltaic system.
At that time, the decision was made from a different perspective. Now, six months later, we know much more.
We are active in this forum and have gained more experience with the construction situation. At first, we were completely focused on getting absolutely EVERYTHING from a single source, since we have very little technical knowledge in construction trades.

But is it really realistic to get a 4.2 kWp system, complete with inverter and all installations, for under €5000 gross (about $5400)?
At that time, I saw few real “offers,” but what you read online regarding costs more closely matched our general contractor’s quote, not half of that.

kati1337 schrieb:

But is it really realistic to get a 4.2 kWp system, complete with inverter and all installations, for under €5,000 gross?

No, it isn’t. Prices are always quoted net because you only pay net and reclaim the VAT.
For that system size (which hardly anyone opts for, since installation costs are disproportionately high), €1,850 is definitely too much. With your €7,250 net budget, a system around 5.5–6 kWp should be possible.

€7250 net should rather bring about 6.6 kWp. I wouldn’t pay more than €1100 net anymore, even for "smaller" systems.

Of course, it also depends on the components; LG is simply more expensive than JA. Whether it’s worth it is a different question altogether...