Gas heating + solar vs. pellet heating

Hello everyone,

we are renovating our house and extending it. At the moment we heat with electricity and want to change this as part of the renovation. Since there is no natural gas in our street, my idea was to switch to a liquefied gas heating system. We will be heating two residential units with the system (90 sqm + 130 sqm).

Our architect suggested a pellet heating system as an alternative, so I need more opinions as decision support on the following questions:

Liquefied gas:
- How high are the acquisition costs of a liquefied gas heating system?
- How expensive is a solar thermal system for hot water as a "renewable fig leaf"?
- Can solar thermal be subsidized and to what extent?
- Would you buy or rent the gas tank?
- What does an inspection by an expert and maintenance cost if I buy the gas tank and have to carry out the maintenance myself?

Pellet:
- How prone are the conveyor systems in pellet heating systems from the silo to the burner?
- How is the noise level when the heating system is fed?
- What can be subsidized (keyword BAFA subsidy)?
- Can the silo be placed in the basement and what requirements are there for the silo then? (keyword moisture)
- What about fine dust pollution?

Thank you very much in advance for your opinions.

Hi,
I have a liquefied gas tank. I dismissed the purchase because of the 'rental costs'. The tank costs 179€/year rent. This includes all maintenance and inspection costs. If I had bought the tank, I would have had to pay around 2000€. After 10 years, there would be an inspection costing about 300€ (as of today, who knows what it will be in 10 years).

So it doesn't make much difference. However, the rental tank has a disadvantage because you commit yourself to the landlord for the gas supply. But the price of gas has so far been at market level, so I don't feel indirectly ripped off through the gas price.

- What are the acquisition costs of a liquid gas heating system?
- How expensive is a solar thermal system for hot water as a "regenerative fig leaf"?
- Can you get funding for solar thermal and to what extent?

The costs are the same as for any other gas heating system:
€6,000 - €8,000 for the system, hot water storage tank, chimney draft, and connections
€3,000 - €10,000 for radiators/underfloor heating and piping, depending on size and requirements
€2,000 - €6,000 for potable and hot water pipes to the bathrooms/faucets

During renovation, the EE-WärmeG should not apply (except for municipal requirements and I think in BW), so you don't need solar thermal as a fig leaf. If you need it for KfW subsidies for an efficiency house, calculate €7,000 for 10m² for hot water and heating. The roof should have a southern orientation and the collectors should be mounted at a 45-70° tilt or the roof should be correspondingly steep.

There is funding from BAFA for solar hot water support: €500 + €500 if a new boiler is installed or €2,000 + €500 for hot water + heating.

Additionally, KfW individual measures (10% subsidy) and partly state programs through state banks or municipal subsidies.

Whether it’s worth it, you have to decide for yourselves. In many cases, it’s a zero-sum game.

Pellets are also subsidized by BAFA and KfW. I don't know the subsidy rates; they are listed on the BAFA website. They can be combined, as long as other subsidies for the subsidized measure in total do not exceed the BAFA subsidies.

What about heat pumps? Are you planning a screed renewal? Then you can install underfloor heating at the same time and use the heat pump efficiently and save yourself the pellet or gas refilling hassle.

Hello
First of all, thank you for the feedback. We want to keep the screed in the existing structure, which is why the heat pump was excluded from consideration.

Regards