ᐅ Is it practical to install a photovoltaic system on the west or east side of a building?
Created on: 5 Jan 2020 18:42
K
kaho674
Hello,
we are wondering whether we should install a photovoltaic system on the roof in the near future. The empty conduits for it are already in place. However, we have a hipped roof. On the south side, there is just over 20m² (215 sq ft) available for the system. Would it make sense to also use the west (or east) side to increase the area, even if the sun doesn’t hit it at the optimal angle?
we are wondering whether we should install a photovoltaic system on the roof in the near future. The empty conduits for it are already in place. However, we have a hipped roof. On the south side, there is just over 20m² (215 sq ft) available for the system. Would it make sense to also use the west (or east) side to increase the area, even if the sun doesn’t hit it at the optimal angle?
Bookstar schrieb:
Come on. The DAX averages a 14% annual return over that kind of period. You might as well pack up your panels on the cabin, which will end up as hazardous waste anyway.Completely different risk category, so nonsense.
halmi schrieb:
A photovoltaic system is almost always cost-effective, except if you pay 2000+ euros per kWp. We are now at 9.6 kWp fully installed and complete for just under 12,500€ gross. Yield forecast is over 10,000 kWh per year with an ideal southwest orientation. All discreetly financed for less than 1%.I recently entered our data into an online calculator. It showed almost 17 years until break-even. Maybe I’m doing something wrong—or maybe Hamburg just doesn’t get enough sun.
At what point does it become cost-effective for you, and with what system size?
In general, you can say that financing over the entire term is quite manageable. Get a few quotes prepared; the cost per kWp for a system size of around 9-10 kWp should be about €1100-1200 net. It will be slightly higher if the system is smaller and somewhat less if you plan a larger system.
nms_hs, on one hand, you save on your own electricity consumption, and on the other hand, you receive feed-in compensation. For example:
Annual yield of the system: 10,000 kWh
Total annual electricity consumption (air-to-water heat pump, controlled residential ventilation, household electricity): 7,500 kWh
Own consumption: 30% of 7,500 kWh = 2,250 kWh * current electricity cost of 25.04 cents = €563 savings per year
Feed-in compensation: 7,750 kWh * 0.9875 cents = €765 compensation
Total income: €563 + €765 = €1,328 per year
System cost: €12,500
This means the system pays off, including interest and insurance, in about 11-12 years. The higher the electricity price rises, the more savings the system generates, and the payback period shortens accordingly.
nms_hs, on one hand, you save on your own electricity consumption, and on the other hand, you receive feed-in compensation. For example:
Annual yield of the system: 10,000 kWh
Total annual electricity consumption (air-to-water heat pump, controlled residential ventilation, household electricity): 7,500 kWh
Own consumption: 30% of 7,500 kWh = 2,250 kWh * current electricity cost of 25.04 cents = €563 savings per year
Feed-in compensation: 7,750 kWh * 0.9875 cents = €765 compensation
Total income: €563 + €765 = €1,328 per year
System cost: €12,500
This means the system pays off, including interest and insurance, in about 11-12 years. The higher the electricity price rises, the more savings the system generates, and the payback period shortens accordingly.
kaho674 schrieb:
Sorry if I don’t fully understand the financial models, but do I get it right that depending on the system size, it can even be worthwhile to finance it fully?Yes, that's exactly the case. I financed my 24.5 kWp system completely.
I calculated the financing so that I have a positive cash flow from the start, meaning I never have to pay upfront (except for the VAT until I get it back from the tax office).
Unfortunately, this means €1700 don’t stay with me but go to the bank, but on the other hand I didn’t have to provide any equity and could use it for the special repayment of my mortgage.
I pay 1.03% interest through KfW.
Bookstar schrieb:
I don’t see any risk there. Over that time frame, it’s negligible, and if you want, you can diversify further with a global ETF. But the average German prefers to keep money in a savings account, I know.
The fact that you can sell the shares also argues against photovoltaics being a concentration risk.
The advantage of photovoltaics is the financing options.If you can ignore risks, of course everything always looks rosy.
Concentration risk? Ridiculous. Photovoltaic systems in typical sizes cost up to €10,000 (around $10,900). Plus, you can finance them almost for free, and you can fully deduct the costs. Zero personal capital required, if that’s what you want.
And yet, in the same breath, recommending the DAX, which consists of only 30 companies, represents a small region, and covers only a few sectors.
By the way, the DAX has a risk level of 6 (out of 7) according to SRRI. And the 14% (unverified) return naturally fluctuates and is based on historical data. With photovoltaics, you have a 20-year government-backed guarantee. Comparing apples and oranges.
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