ᐅ Geothermal Heat Pump Cost Efficiency

Created on: 9 Jul 2018 20:53
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Pepsan
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Pepsan
9 Jul 2018 20:53
We are currently building a single-family house (Pinneberg, construction company Kage, 119 sqm (1280 sq ft), 40-degree gable roof, no basement) and I am considering a ground source heat pump. The building consultant advised against it because it is too expensive: 13,000 euros more than a conventional gas heating system.

At the moment, we live in a rented semi-detached house (3 people, built in 2008, 130 sqm (1400 sq ft), gas heating) and our gas consumption costs about 60 euros/month = 720 euros/year.
If the heating cost with a ground source heat pump is only half as much (according to the advisor’s rough estimate), then you calculate 13,000 / (0.5 * 720) = 36 years performance factor!!!
Is that correct?

What do you think about the economic efficiency of a ground source heat pump?

PS
Sorry, German is not my best language, please be patient... :-{
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nordanney
9 Jul 2018 21:34
I can only share from our new build about four years ago – back then it was Kfw 70 standard.

We heated 300 sqm (around 3,230 sq ft) for just under 400€ per year. Comfortable temperature was just below 22°C (72°F). We had a mechanical ventilation system with heat recovery installed. I can’t say how much gas it would have cost. But when we sold the house two years ago, the low energy costs definitely paid off...
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Bookstar
9 Jul 2018 21:43
Completely uneconomical, you will never manage to make it add up. I would definitely recommend gas! Especially for a small house of 120 m² (1,290 sq ft), it simply doesn’t make sense.
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Pepsan
9 Jul 2018 21:43
OK, thanks.

But 300 m² (3,229 ft²) and 119 m² (1,281 ft²) are quite different. Of course, a 300 m² (3,229 ft²) house requires a larger heating system, whether gas or heat pump, but I don’t expect it to be much more expensive. However, the operating costs for 300 m² (3,229 ft²) are much higher than for 119 m² (1,281 ft²).

The larger the house, the more cost-effective the heat pump becomes.
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Pepsan
9 Jul 2018 21:49
Let’s say, just theoretically, the heat pump uses NO gas or electricity.
Then 13,000 EUR / 720 EUR/year = 18 years.
Of course, we don’t know future gas prices; gas will likely become more expensive, but with a heat pump, we also have to pay higher interest rates for the larger loan.

Not economical.
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Bookstar
9 Jul 2018 22:09
That’s how it is, and your heat pump also requires a significant amount of electricity.