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
M
Micha&Dany27 Nov 2011 07:09Hello Perlenmann,
Yes, I am in favor of photovoltaic systems because I truly believe in them 🙂
But again: I know that with every system you have to carefully calculate whether the financial aspect really works out.
System availability does not indicate the yield, but the downtime of the system. For example, if the inverter is faulty or there is a grid outage, then you cannot feed in any power. And with 97% availability, that means your system will be down for a maximum of 11 days per year.
The orientation—and therefore the yield—is included in the 850 kWh/kWp*a (Ruhr area) value I used. With poorer orientation, this value decreases—which naturally changes the calculation and ultimately the return.
If you have a system oriented strongly to the west, for example, and only achieve about 700 kWh/kWp*a, then the system will not be worthwhile! (In that case, I wouldn’t build one either!)
As for the loan: I’m not fully up to date anymore. I don’t know how banks handle this nowadays, but up until about two years ago, banks accepted the system itself as collateral. The loan could be repaid solely from the feed-in tariff. This means that the system had no impact on your bank account for the first 12 to 14 years. What you earned from the system you passed directly to the bank. Nothing more. So the system financed itself.
However, this may have changed since then...
Best regards
Micha 😎
Yes, I am in favor of photovoltaic systems because I truly believe in them 🙂
But again: I know that with every system you have to carefully calculate whether the financial aspect really works out.
System availability does not indicate the yield, but the downtime of the system. For example, if the inverter is faulty or there is a grid outage, then you cannot feed in any power. And with 97% availability, that means your system will be down for a maximum of 11 days per year.
The orientation—and therefore the yield—is included in the 850 kWh/kWp*a (Ruhr area) value I used. With poorer orientation, this value decreases—which naturally changes the calculation and ultimately the return.
If you have a system oriented strongly to the west, for example, and only achieve about 700 kWh/kWp*a, then the system will not be worthwhile! (In that case, I wouldn’t build one either!)
As for the loan: I’m not fully up to date anymore. I don’t know how banks handle this nowadays, but up until about two years ago, banks accepted the system itself as collateral. The loan could be repaid solely from the feed-in tariff. This means that the system had no impact on your bank account for the first 12 to 14 years. What you earned from the system you passed directly to the bank. Nothing more. So the system financed itself.
However, this may have changed since then...
Best regards
Micha 😎
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