ᐅ Photovoltaic System and Air-to-Water Heat Pump – Profitability for a Single-Family Home Built to KfW 55 Energy Efficiency Standard
Created on: 11 Jan 2022 23:19
M
Maxwell8
Hello,
we are building a fairly large KFW55EE house with external dimensions of approximately 10x14m (33x46 feet) and a roof pitch of 15° (roof surfaces facing north and south).
We have a lot of window area (100m2 (1,076 sq ft)) and expect an energy consumption of about 7-9k kWh per year due to the size.
Heating is provided by underfloor heating with the Tecalor THZ 504 air-to-water heat pump.
Feed-in tariffs are no longer significant, but the electricity price is currently 45 cents/kWh.
We would have to finance the photovoltaic system ourselves because there is no sufficient budget left.
> From a profitability perspective, does a photovoltaic system make sense in our situation?
> What size and costs should we expect?
> Should it be installed directly or should we first prepare with conduits?
> We also have an attached 6x6m (20x20 feet) flat-roof garage on the east side. Would adding photovoltaic panels there be beneficial?
I will, of course, speak with companies but would like to gather some opinions beforehand.
Thank you in advance. 🙂
we are building a fairly large KFW55EE house with external dimensions of approximately 10x14m (33x46 feet) and a roof pitch of 15° (roof surfaces facing north and south).
We have a lot of window area (100m2 (1,076 sq ft)) and expect an energy consumption of about 7-9k kWh per year due to the size.
Heating is provided by underfloor heating with the Tecalor THZ 504 air-to-water heat pump.
Feed-in tariffs are no longer significant, but the electricity price is currently 45 cents/kWh.
We would have to finance the photovoltaic system ourselves because there is no sufficient budget left.
> From a profitability perspective, does a photovoltaic system make sense in our situation?
> What size and costs should we expect?
> Should it be installed directly or should we first prepare with conduits?
> We also have an attached 6x6m (20x20 feet) flat-roof garage on the east side. Would adding photovoltaic panels there be beneficial?
I will, of course, speak with companies but would like to gather some opinions beforehand.
Thank you in advance. 🙂
R
RotorMotor23 Jan 2022 20:24Maxwell8 schrieb:
Is it still worth having two meters nowadays, or should everything run through just one?That depends on many factors: individual consumption, photovoltaics, basic fees, price per kWh, and so on.Maxwell8 schrieb:
With our consumption, the difference can easily be over €1000 per year.Oh, then you must have a high consumption. Even with photovoltaics?WilderSueden schrieb:
Do you even have a choice? In most grids, the supplier now requires two meters, regardless of whether it benefits you.Who exactly requires that?W
WilderSueden23 Jan 2022 20:28RotorMotor schrieb:
Who requires that?The grid operator. In my case, it is Netze BW (EnBW), and for you, it is probably someone else 😉This is specified in the connection conditions, and the electrician installing the meters must comply with it.
Well, with all due respect, during the first year we were also with EnBW, and the only requirement they had was that if we wanted a heat pump tariff, it had to include a load control period and, of course, a second meter. Otherwise, I could have just gone with the standard tariff.
D
Deliverer23 Jan 2022 20:37There must be something wrong. A difference of 1000 euros corresponds to 7700 kWh just from the grid. With a current heat pump, that would be 30,000 kWh of heat. Before worrying about the meters, I would get a plumber to take a look.
In general, nowadays it usually doesn’t make sense to install a second meter in new builds (due to the additional base fee). As the share of renewable energy increases, the price difference between heat pump electricity and regular electricity will also decrease, so it will become less worthwhile for everyone.
You also have to consider that if the heating system is not allowed to run for about four hours a day, you need a different system. It would need to be roughly one-sixth larger to compensate. If there is no better alternative anyway, that’s fine. But if I have to choose the next larger model for that reason, I would skip installing a second meter.
In general, nowadays it usually doesn’t make sense to install a second meter in new builds (due to the additional base fee). As the share of renewable energy increases, the price difference between heat pump electricity and regular electricity will also decrease, so it will become less worthwhile for everyone.
You also have to consider that if the heating system is not allowed to run for about four hours a day, you need a different system. It would need to be roughly one-sixth larger to compensate. If there is no better alternative anyway, that’s fine. But if I have to choose the next larger model for that reason, I would skip installing a second meter.
W
WilderSueden23 Jan 2022 20:48I researched this topic about a year ago and was a bit frustrated because I found a document that clearly required a separate meter for heat pumps with a usable capacity (larger than 2 or 3 kW). However, I can’t find that document anymore. Actually, I don’t really want a second meter either.
D
Deliverer23 Jan 2022 20:50I never had one, and my father had it removed without any inquiries. So it seems to depend on the network operator...
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