Hello. We would also like to install a photovoltaic system and currently have three quotes. So far, we have received two, and the third one is still being prepared.
A local provider offered us the following:
40 x 410 W mono S4 half-cut modules = 16.4 kWp
Q.HOME+ ESS HYB- G3 3-phase 15.0 kWp inverter & 6.0 kW battery storage
Including installation, scaffolding, new distribution board, grounding rod, equipotential bonding bar, and all formalities and registration for just under €29,400.
The modules are arranged facing south-southwest and some towards northeast.
The second offer is almost the same price but has significantly lower kWp and comes from a company operating nationwide in Germany.
Do you think this is reasonable? I personally find it still quite expensive and am curious about the third offer. Are the components okay?
A local provider offered us the following:
40 x 410 W mono S4 half-cut modules = 16.4 kWp
Q.HOME+ ESS HYB- G3 3-phase 15.0 kWp inverter & 6.0 kW battery storage
Including installation, scaffolding, new distribution board, grounding rod, equipotential bonding bar, and all formalities and registration for just under €29,400.
The modules are arranged facing south-southwest and some towards northeast.
The second offer is almost the same price but has significantly lower kWp and comes from a company operating nationwide in Germany.
Do you think this is reasonable? I personally find it still quite expensive and am curious about the third offer. Are the components okay?
I don’t find it that expensive for the current times. The days of bargain prices are long gone. The new distribution box along with wiring, a completely new grounding system, and the scaffolding rental already add up significantly. It’s nice to have fairly powerful modules at first, and the storage system really depends on what costs are involved. I don’t think it will get much cheaper. On top of that, there is the advantage of having a contact person close by.
Regarding the offer, I would take another look at how much the storage system costs and how long the warranty lasts. Storage systems are often greatly overestimated.
Calculate about 170 cycles per year, or optimistically 200. If I assume 200 cycles, to be accurate I’d also need to consider losses (around 5% each way, depending on the storage system). For simplicity, let’s ignore that for now.
So, let’s say 200 cycles with 6 kWh each, resulting in annual savings. Using the current price cap of 0.4€ (about 0.4 USD) per kWh, that equals 480€ (about 480 USD) saved by not buying electricity from the grid. Subtract the lost feed-in tariff of about 0.08€ (0.08 USD) per kWh for 1,200 kWh → 480€ - 96€ = 384€ (480 USD - 96 USD = 384 USD) per year.
If your storage system has a 10-year warranty, it shouldn’t cost more than 3,840€ (about 3,840 USD) to avoid a loss if it fails completely shortly after the warranty expires. For 5 years, the limit would be only half of that.
This calculation already includes two optimistic assumptions for simplicity: the number of full cycles per year and ignoring losses during charging and discharging. I have also not factored in that storage capacity decreases over time.
If electricity prices rise significantly in the future while the feed-in tariff remains flat, the calculation would look very different. But no one has a crystal ball.
If you also consider that the money spent on a storage system, which may be economically uncertain, could instead be invested in additional photovoltaic modules (assuming you have the space), then the storage system looks even less favorable. Photovoltaic installations almost certainly pay for themselves before their warranty expires. The fuller your roof, the better.
Calculate about 170 cycles per year, or optimistically 200. If I assume 200 cycles, to be accurate I’d also need to consider losses (around 5% each way, depending on the storage system). For simplicity, let’s ignore that for now.
So, let’s say 200 cycles with 6 kWh each, resulting in annual savings. Using the current price cap of 0.4€ (about 0.4 USD) per kWh, that equals 480€ (about 480 USD) saved by not buying electricity from the grid. Subtract the lost feed-in tariff of about 0.08€ (0.08 USD) per kWh for 1,200 kWh → 480€ - 96€ = 384€ (480 USD - 96 USD = 384 USD) per year.
If your storage system has a 10-year warranty, it shouldn’t cost more than 3,840€ (about 3,840 USD) to avoid a loss if it fails completely shortly after the warranty expires. For 5 years, the limit would be only half of that.
This calculation already includes two optimistic assumptions for simplicity: the number of full cycles per year and ignoring losses during charging and discharging. I have also not factored in that storage capacity decreases over time.
If electricity prices rise significantly in the future while the feed-in tariff remains flat, the calculation would look very different. But no one has a crystal ball.
If you also consider that the money spent on a storage system, which may be economically uncertain, could instead be invested in additional photovoltaic modules (assuming you have the space), then the storage system looks even less favorable. Photovoltaic installations almost certainly pay for themselves before their warranty expires. The fuller your roof, the better.
B
Bausparfuchs3 May 2023 21:43I don’t want to start another discussion about storage here. But the idea of filling the entire roof with panels and feeding in as much electricity as possible has long become outdated due to the relationship between electricity purchase costs and feed-in tariffs.
To put it more clearly: You install a photovoltaic system on your roof. And within about three weeks at the latest, you regret not having installed a battery storage system. If it even takes that long. When I check my app in the evening and see zero grid consumption, it feels really good. Without storage, the consumption would probably be around 10 kWh.
The amount of electricity fed into the grid is only of minor interest to me. Because I get a feed-in tariff of 0.80 euros per kWh, but pay 4.80 euros per kWh for electricity.
I still have to pay the energy supplier 4 euros. Despite having a photovoltaic system.
With my storage system, I pay zero euros to my energy supplier. And I don’t have to worry if the sun doesn’t shine tomorrow.
The battery manages that.
With a ratio of 6:1 between the feed-in tariff and electricity costs, every storage system pays off.
And believe me, it’s very frustrating when your electricity meter keeps running despite the photovoltaic system. Not to mention when you’re at work, the sun is shining, and you can’t operate your high-energy appliances. I can also do laundry or use the oven in the evening without noticeable grid consumption.
To put it more clearly: You install a photovoltaic system on your roof. And within about three weeks at the latest, you regret not having installed a battery storage system. If it even takes that long. When I check my app in the evening and see zero grid consumption, it feels really good. Without storage, the consumption would probably be around 10 kWh.
The amount of electricity fed into the grid is only of minor interest to me. Because I get a feed-in tariff of 0.80 euros per kWh, but pay 4.80 euros per kWh for electricity.
I still have to pay the energy supplier 4 euros. Despite having a photovoltaic system.
With my storage system, I pay zero euros to my energy supplier. And I don’t have to worry if the sun doesn’t shine tomorrow.
The battery manages that.
With a ratio of 6:1 between the feed-in tariff and electricity costs, every storage system pays off.
And believe me, it’s very frustrating when your electricity meter keeps running despite the photovoltaic system. Not to mention when you’re at work, the sun is shining, and you can’t operate your high-energy appliances. I can also do laundry or use the oven in the evening without noticeable grid consumption.
Bausparfuchs schrieb:
With a ratio of 6:1 between compensation and electricity costs, every storage system pays off. That's just one factor. The much bigger one is the purchase price. And of course, how long the battery lasts, but that’s hard to determine at the time of purchase.
Bausparfuchs schrieb:
There are still 4 euros left that I have to pay to the energy provider, despite the photovoltaic system. But you have paid the battery seller upfront and immediately for (hopefully) many years – maybe by the end of the battery’s lifespan you come out ahead, or maybe not.
PS: I have a battery myself and appreciate it a lot. However, I bought it at different price levels and back then claimed both VAT and subsidies.
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