ᐅ New Single-Family Home Construction – Gas or Air Source Heat Pump + Photovoltaic System + Energy Storage?

Oh, come on, the "green" hydrogen will fix everything. I fully trust the leading figures Altmaier, Bareiß & Co.

french_fry schrieb:

We have underfloor heating upstairs and downstairs

Good. Is there a heating load calculation? How is the underfloor heating designed? Maximum supply temperature? Have the desired temperatures for the individual rooms been specified?

If a supply temperature of 40 degrees Celsius (104 degrees Fahrenheit) is not required, I would also tend to prefer an air-source heat pump.

Can you wait to make your decision until after winter? I mean this winter, which is only just beginning, but gas storage facilities are already empty and some suppliers are no longer accepting new customers...

french_fry schrieb:

We didn’t get good advice for our house build due to a lack of knowledge and are currently constructing an energy regulation-compliant house with gas plus solar thermal.

I don’t necessarily see that as poor advice. The general contractor builds their houses this way, so why not? It is proven and very efficient technology. Without any gimmicks and without huge additional consumption—only if a sensor malfunctions or the supply temperature is set 1–2°C (2–4°F) higher than needed.

The only real downside is the use of fossil fuel. Price fluctuations for electricity are significantly higher than for gas. With solar thermal, you get plenty of hot water from March to October, and if you want, you can install photovoltaic panels on the rest of the roof. The biggest advantage of a gas boiler is that, compared to any type of heat pump, it pays off economically even without subsidies. For heat pumps (unless you install or maintain them yourself), it usually isn’t economically worthwhile. The technology is excellent, no question, but it’s simply sold to end customers at too high a price.

And the horror stories about price increases and “evil” gas aren’t really relevant as of today. Sure, the Green party is entering parliament now. We’ll see what that brings. But currently, the gas price increase for a modern single-family home (not one from the last century) is only marginal. The situation is much worse with the beloved car.

Mycraft schrieb:

Price fluctuations are significantly greater for electricity than for gas.

That is incorrect. Why do you claim that?

Sorry, my mistake.

Fluctuations in electricity prices are actually minimal. The trend only goes one way: up... and on average, prices simply double every 20 years. This is unlikely to improve in the future, as current policies will significantly increase demand. Gas prices, on the other hand, are quite stable and still relatively cheap. All the raw material price data is freely available through various sources and can be verified.

Electricity price per kWh in 2000 = ~14c
Gas price per kWh in 2000 = ~4c

Electricity price per kWh in 2021 = ~32c
Gas price per kWh in 2021 = ~6.35c

I don’t just base this on abstract prices, but also on direct comparisons of several properties. Electricity bills have increased much more over recent years than gas bills, assuming the same consumption. The properties themselves haven’t changed; they are used the same way and have consistent consumption values. Only the bills have gone up, despite regular switching, bonuses, and so on.

Of course, ideally a heat pump converts 1 kWh of electricity into 4 kWh of heat, which is great. But... but... but...