ᐅ Solar / Photovoltaics from an Economic Perspective

merlin83 schrieb:
Statements like that are unfortunately not convincing without an example calculation. Didn’t you do any calculations at all?

You’re of course right. However, I don’t have my documents with me at work and also don’t have time for detailed calculations.

So now (while watching “Walking Dead”) I have some time to do this. But only a rough calculation, since I don’t feel like doing a big Excel spreadsheet.

Purchase price: 9,500 euros minus refunded VAT 1,526 euros = about 8,000 euros
8,000 euro loan at 1.5% interest = 120 euros per year × 20 years = 2,400 euros
8,000 + 2,400 = 10,400 euros total financing cost

Payment from the electricity provider: 50 euros per month = 600 euros per year (there will probably be a small surplus by year-end)
600 euros × 20 years = 12,000 euros income over 20 years

This doesn’t yet take into account that around 20–25% of the production is used for self-consumption (you can conservatively estimate each kWh at at least 0.20 euro) = saved electricity costs. Also, the interest expense decreases with each monthly repayment. However, potential maintenance costs were also not included (since I currently have no idea how much these might be).

To round it off from a tax perspective: VAT must be paid to the tax office on the income from electricity feed-in, as well as on the self-consumption. However, most of this can be reclaimed later through the tax return (by applying depreciation on the system, the interest, etc.).

I hope this helps you a bit.

PS: I track daily data on electricity consumption, production, feed-in, etc. in Excel, so I have a fairly good overview regarding our system.

nordanney schrieb:
Solar PV is very cost-effective for us (connected to the grid at the beginning of 2014). It pays off after just over 10 years with full financing.

Could you please share some data (screenshot) from your solar PV system?

For me, it’s also around 10 years; the solar PV system has been operating since 07/2011.

Solar PV system (8.225 kWp).
Feed-in tariff: € 0.2874
Self-consumption: € 0.1236

Value 2012: (Period = 07/2011 to 2012)

Value 2015: As of today (19.10.2015)

Of course, the new house will also have a solar PV system with a battery storage. At the end of 2015, the Tesla Powerwall will be launched...

Ecart schrieb:

The new house will, of course, have a photovoltaic system with a battery storage again. The Tesla Powerwall is expected to be delivered by the end of 2015...

I had asked this question some time ago – maybe you have more information on it: Battery storage for photovoltaic electricity is, as far as I know, subsidized. Do you have any details on whether the (relatively affordable) Tesla Powerwall will also qualify for such subsidies?

Take a look at this from KfW:

275
Loan
Renewable Energies – Storage
Generating and storing electricity from solar energy

With the funding product Renewable Energies – Storage, we support the new installation of stationary battery storage systems in combination with photovoltaic systems.

Your funding consists of 2 parts:

a low-interest loan from KfW
a repayment grant funded by the Federal Ministry for Economic Affairs and Energy (BMWi).

Also applicable for storage retrofitting of photovoltaic systems commissioned after 31.12.2012.

BG
Ecart

@Ecart
Thank you. I was already familiar with the KfW program that includes a repayment subsidy.

However, I’m not sure whether Tesla batteries are also eligible for funding here. On one hand, the battery is still completely new (often, product lists are used to determine eligibility for funding). On the other hand, the batteries are expected to become quite affordable (I once read about roughly 3,000 euros for 10kWh).

f-pNo schrieb:
@Ecart
Thank you. I was already aware of the KfW program with repayment subsidy.

However, I’m not sure if Tesla batteries are included in the funding here. On one hand, because the battery is completely new (often there are product lists used for funding). On the other hand, because the batteries are supposedly becoming quite affordable (I once read about roughly 3,000 euros for 10 kWh (6.2 kWh)).

The battery isn’t quite that cheap after all. The Tesla price mentioned is, as far as I know, the wholesale price. A dealer markup still needs to be added. Additionally, an inverter costing about €1,500 (around $1,600) must be purchased, and installation will also incur costs.
I would still like to have a Powerwall.