Hello,
I want to have a house built— a single-family home with 112m² (1,206 sq ft) of living space. I assume that, according to the 2009 Energy Saving Ordinance, all houses are very well insulated. Since I’m not a fan of throwing my money away to big energy companies, the house will be equipped with an air-to-water heat pump, a ventilation system with heat recovery, and a photovoltaic system on the roof.
My simple thinking is this: the photovoltaic system generates electricity, the air-to-water heat pump uses electricity, and the ventilation system helps prevent mold and, because it operates with heat recovery, I won’t need as much electricity to keep the house warm.
I’m open to being convinced otherwise!
Best regards
I want to have a house built— a single-family home with 112m² (1,206 sq ft) of living space. I assume that, according to the 2009 Energy Saving Ordinance, all houses are very well insulated. Since I’m not a fan of throwing my money away to big energy companies, the house will be equipped with an air-to-water heat pump, a ventilation system with heat recovery, and a photovoltaic system on the roof.
My simple thinking is this: the photovoltaic system generates electricity, the air-to-water heat pump uses electricity, and the ventilation system helps prevent mold and, because it operates with heat recovery, I won’t need as much electricity to keep the house warm.
I’m open to being convinced otherwise!
Best regards
perlenmann schrieb:
That means anyone who has extra money and doesn’t need a loan for it could get even higher returns.
Strange, why is this done so rarely?
And who guarantees that the government will pay for 20 years?
It’s all too much for me. I don’t want to take out a bigger loan on top of the house just to maybe make some profit in 20 years.
If the numbers add up, it would be nice... but still too risky for me.Also true.
P
perlenmann25 Nov 2011 08:29The good thing is you can calculate everything clearly.
*Irony on* The government has never changed anything that’s valid for 20 years! *Irony off*
Do you already have a system?
You do know you have to pay tax on the income, right?
It’s also clear that next year there will be about 4 cents less again (I think).
I guess everyone really has to decide for themselves, but to bring a “celebrity” into the discussion… Daniel Küblböck reportedly invested all his money into this and had great success. That was a few years ago, and he paid in cash.
But the 3.x% return didn’t take into account the repayment of the main loan installment, did it?
The system might run for 30 years, but the income doesn’t disappear all at once; it’s steady over time. The increase in temperature in the form of heat (solar radiation) might even have a positive effect, but storms could possibly tear the system off your roof.
Additionally, the photovoltaic system still needs to be insured (I don’t know the costs).
In any case, for me the risk isn’t worth it. The best loan is the one you don’t have!
And I would prefer a fixed interest rate of 4.5% over 5 years rather than possibly 3.x% over 20 years.
PS: An 8 kWp system requires roughly 64 m² (690 ft²) of space in OPTIMAL orientation, to my knowledge!
*Irony on* The government has never changed anything that’s valid for 20 years! *Irony off*
Do you already have a system?
You do know you have to pay tax on the income, right?
It’s also clear that next year there will be about 4 cents less again (I think).
I guess everyone really has to decide for themselves, but to bring a “celebrity” into the discussion… Daniel Küblböck reportedly invested all his money into this and had great success. That was a few years ago, and he paid in cash.
But the 3.x% return didn’t take into account the repayment of the main loan installment, did it?
The system might run for 30 years, but the income doesn’t disappear all at once; it’s steady over time. The increase in temperature in the form of heat (solar radiation) might even have a positive effect, but storms could possibly tear the system off your roof.
Additionally, the photovoltaic system still needs to be insured (I don’t know the costs).
In any case, for me the risk isn’t worth it. The best loan is the one you don’t have!
And I would prefer a fixed interest rate of 4.5% over 5 years rather than possibly 3.x% over 20 years.
PS: An 8 kWp system requires roughly 64 m² (690 ft²) of space in OPTIMAL orientation, to my knowledge!
perlenmann schrieb:
...That the temperature increase in the form of heat (solar radiation) might even have a positive effect,.. Are you sure? Then try calculating the cooling loads of new buildings. ;-) Photovoltaic systems indirectly make a significant contribution to summer heat protection, provided they are ventilated at the back and not integrated! This does not appear in any energy-saving regulations/planning permission verification or photovoltaic simulations!
Best regards
M
Micha&Dany26 Nov 2011 08:27Hello Perlenmann
Yes, you can if you want to – or you can make the numbers look bad – that’s just as possible.
True, you’re right, they *could* do it. However, the chance is extremely low with the Renewable Energy Act. Because the government does not bear the costs. It’s not the government paying the feed-in tariff but the utility company. (And therefore the electricity consumers.)
Since you hang around in this forum, I assume you are building a house, planning to build one, or have recently built one.
When I think about the changes the government has made for homeowners in the last 10 years *has*—which could also cost a lot of money—then everyone should rather build 100 photovoltaic systems than 1 house!
Since I also hang around in this forum, one can assume that I am in the process of building a roof area for a photovoltaic system. Coincidentally, the space under the photovoltaic system can also be used for living, but that’s really just coincidence.
And when the roof is finished, I will do exactly that calculation for my roof—considering orientation and tilt, current system price, and the feed-in tariff. If a reasonable return comes out of it, I will definitely install a system.
Right, I already mentioned that—it’s a personal decision. And it’s not just some minor celebrities investing in these systems.
I already mentioned that the last two years (2009 + 2010) were record years. Prices have dropped significantly while feed-in tariffs were high (too high). Returns of 10-12% were common, not the exception. That’s why the government thankfully intervened and cut feed-in tariffs. In 2012 it will only be 24.43 cents. Thus, the tariff has been lowered by 43.2% from 2009 to 2012.
Meanwhile, there is a “dynamic cap,” meaning the tariff decreases depending on newly installed capacity. The government wants an annual increase of 3 GW. If the increase is about this size, the tariff is cut by 9%; if it’s lower, the cut is smaller; and if it’s higher, it can be cut by up to 15%. For comparison: increase in 2010: 7.4 GW (=7,400 MW); 2009: 9.8 GW (=9,800 MW); estimate for 2011: 2.8 GW. (All numbers are only for Germany, not worldwide! And all figures without guarantee.)
So if anyone tells me photovoltaic systems are not being installed anymore *laughs*
I am neither a banker, tax advisor, nor business economist—I calculated this *exemplarily* to the best of my knowledge and belief—if you find another mistake, feel free to keep it.
Whether a storm damages the system depends solely on the quality of the installation. If you look for a cheap provider who doesn’t understand tension and compression loads and for whom structural calculations are something to eat, yes, then the system will fly off your roof in the next storm. If properly installed, it will even withstand a hurricane like Kyrill.
As I’ve said multiple times—that’s a personal decision. There is no universally right or wrong.
But therefore you cannot generally call photovoltaics wrong or nonsense. You have to look closely here as well.
Yes, roughly (maybe a little less). It depends on the modules used and the dimensions of the roof.
But orientation has nothing to do with the required area—you can also install the system on a north-facing roof—but I can promise you without calculation that it won’t be profitable.
Sunny regards Micha
perlenmann schrieb:
The good thing is, you can always make the numbers work.
Yes, you can if you want to – or you can make the numbers look bad – that’s just as possible.
perlenmann schrieb:
*Irony on*The government has never changed anything that’s valid for 20 years!*Irony off*
True, you’re right, they *could* do it. However, the chance is extremely low with the Renewable Energy Act. Because the government does not bear the costs. It’s not the government paying the feed-in tariff but the utility company. (And therefore the electricity consumers.)
Since you hang around in this forum, I assume you are building a house, planning to build one, or have recently built one.
When I think about the changes the government has made for homeowners in the last 10 years *has*—which could also cost a lot of money—then everyone should rather build 100 photovoltaic systems than 1 house!
perlenmann schrieb:
Do you already have a system?
You know you have to pay taxes on income from it, right?
Next year it’ll go down by 4 cents (I think), that’s clear, too?
Since I also hang around in this forum, one can assume that I am in the process of building a roof area for a photovoltaic system. Coincidentally, the space under the photovoltaic system can also be used for living, but that’s really just coincidence.
And when the roof is finished, I will do exactly that calculation for my roof—considering orientation and tilt, current system price, and the feed-in tariff. If a reasonable return comes out of it, I will definitely install a system.
perlenmann schrieb:
I think that really everyone has to decide for themselves, but to bring a ‘celebrity’ into the discussion... Daniel Küblböck apparently put all his money into it and did great. But that was some years ago and he had the cash upfront.
Right, I already mentioned that—it’s a personal decision. And it’s not just some minor celebrities investing in these systems.
I already mentioned that the last two years (2009 + 2010) were record years. Prices have dropped significantly while feed-in tariffs were high (too high). Returns of 10-12% were common, not the exception. That’s why the government thankfully intervened and cut feed-in tariffs. In 2012 it will only be 24.43 cents. Thus, the tariff has been lowered by 43.2% from 2009 to 2012.
Meanwhile, there is a “dynamic cap,” meaning the tariff decreases depending on newly installed capacity. The government wants an annual increase of 3 GW. If the increase is about this size, the tariff is cut by 9%; if it’s lower, the cut is smaller; and if it’s higher, it can be cut by up to 15%. For comparison: increase in 2010: 7.4 GW (=7,400 MW); 2009: 9.8 GW (=9,800 MW); estimate for 2011: 2.8 GW. (All numbers are only for Germany, not worldwide! And all figures without guarantee.)
So if anyone tells me photovoltaic systems are not being installed anymore *laughs*
perlenmann schrieb:??? I don’t understand that now…
The 3.x% return probably didn’t take into account the elimination of the main annuity repayment, right?
I am neither a banker, tax advisor, nor business economist—I calculated this *exemplarily* to the best of my knowledge and belief—if you find another mistake, feel free to keep it.
perlenmann schrieb:
The system might run for 30 years, but the yield does not disappear all at once, it declines gradually. That the temperature increase in the form of heat (solar radiation) may even have a positive effect, but storms could tear the system off the roof.
In addition, the photovoltaic system must also be insured (I don’t know the costs).
Whether a storm damages the system depends solely on the quality of the installation. If you look for a cheap provider who doesn’t understand tension and compression loads and for whom structural calculations are something to eat, yes, then the system will fly off your roof in the next storm. If properly installed, it will even withstand a hurricane like Kyrill.
perlenmann schrieb:
Anyway, the risk is not worth it for me. The best loan is the one you don’t have!
And I would prefer a 4.5 to 5 years FIXED interest over a possible 3.x% on 20 years.
As I’ve said multiple times—that’s a personal decision. There is no universally right or wrong.
But therefore you cannot generally call photovoltaics wrong or nonsense. You have to look closely here as well.
perlenmann schrieb:
PS: 8 KWp requires about 64 m² in OPTIMAL orientation, according to my knowledge!
Yes, roughly (maybe a little less). It depends on the modules used and the dimensions of the roof.
But orientation has nothing to do with the required area—you can also install the system on a north-facing roof—but I can promise you without calculation that it won’t be profitable.
Sunny regards Micha
P
perlenmann26 Nov 2011 11:54@Micha: Yes, I am building. I only asked because you are so completely in favor. I am also PRO photovoltaic systems, but not if I need a loan for it!
And that was the point I was making. You take out a loan, plus a second one for the photovoltaic system. You have to pay both. If I previously had a monthly payment of €1000 (about $1100), to keep the same financial burden, I now have to pay the photovoltaic loan installment on top of that €1000, which reduces the repayment amount for the main loan!
And of course, YOU need 64m² (690 sq ft) with optimal orientation to achieve your 97% availability. Not everyone has that!
@€: This was not about heat protection, but rather that extreme weather probably produces even more electricity!
And that was the point I was making. You take out a loan, plus a second one for the photovoltaic system. You have to pay both. If I previously had a monthly payment of €1000 (about $1100), to keep the same financial burden, I now have to pay the photovoltaic loan installment on top of that €1000, which reduces the repayment amount for the main loan!
And of course, YOU need 64m² (690 sq ft) with optimal orientation to achieve your 97% availability. Not everyone has that!
@€: This was not about heat protection, but rather that extreme weather probably produces even more electricity!
perlenmann schrieb:
...@€uro: This was not regarding heat protection, but that the extreme weather will probably even generate more electricity! Completely clear, more hours of production, more kWh generated. There is no doubt about that. However, in an overall energy balance, the cooling load during the summer heat period gains significant importance. The Energy Saving Ordinance / KfW subsidy primarily focuses on heating operation from a primary energy perspective in a very one-sided and superficial way! Those who can calculate balances to some extent understand the background. Photovoltaics not only have the advantage of solar energy generation and savings but also the secondary benefit of reducing and saving cooling loads!
Ignoring existing effects in a one-sided manner also leads to incorrect final results!
Best regards
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