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. 🙂
halmi schrieb:
You have to look at it positively; almost 100% of the photovoltaic output in winter goes straight into heating 😉
In 2021, without much optimization, we had 29% self-consumption with a 9.2 kWp system. I think we are now over 50% with our 4.55 kWp system.
However, we work from home, optimize only loosely (turn on the washing machine / dishwasher when the sun is shining), and continuously use a lot of electricity through our IT equipment.
W
WilderSueden14 Jan 2022 12:29Self-consumption is now the key factor for profitability. It doesn’t help if you generate tens of thousands of kWh but feed it into the grid at 7-8 cents while paying much more for your own electricity.
kati1337 schrieb:
and continuously consume a lot of electricity through our IT. Ahem. Charging 2 laptops plus, say, 2 flat screens each at 20W, amounts to about 1 kWh per 10-hour workday.
Or which “IT” is being referred to here?
driver55 schrieb:
Ahem. Charging 2 laptops plus, say, 2 flat-screen monitors at 20W each, adds up to about 1 kWh per 10-hour workday.
Or which “IT” are we actually talking about here?4 monitors, 2 developer workstations running multiple IntelliJ instances (building projects is quite demanding), plus a coffee machine, external audio interface for an XLR microphone, router, access points, and air conditioning in the summer. When the work PCs are off, the gaming PCs come on, with 1000W and 800W power supplies. It all adds up, along with the “other” household electricity usage.
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