Hello everyone!
A quick question:
Why do people actually add solar thermal systems to their gas heating?
Is it because they have to comply with the energy saving regulations?
Wrong, you are allowed to skip solar thermal if other measures reduce energy consumption by at least 15%.
Example:
I’m planning a KfW-55 house with gas heating, solar thermal, controlled ventilation with heat recovery, and excellent insulation.
Now I remove the solar thermal system. What happens?
I lose the KfW-55 status and end up with KfW-70, so I lose a €2,500 subsidy. But I save €6,000 by not installing solar thermal. The operating costs increase by €50 per year due to the missing solar thermal, which adds up to €1,000 over 20 years. So overall, I still save €2,500.
Savings:
€6,000 saved by not installing solar thermal*
- €2,500 lost KfW-55 subsidy
- €1,000 higher operating costs due to no solar thermal*
=======
€2,500
Sounds like an attractive alternative, or is there a major calculation mistake somewhere?
The whole calculation would also apply to a KfW-85 house, which would qualify as a KfW-100 house without the solar thermal.
Best regards
jx7
PS:
Please don’t bring up heat pumps or pellet heating; this is not meant to start a fundamental debate about gas versus heat pumps (with sharp increases in energy prices, heat pumps will eventually become more cost-effective). The initial question is simply: "If using gas, then maybe without solar thermal?"
* Source: xxx-Heizungsvergleich-de "Gas + 5sqm solar thermal"
A quick question:
Why do people actually add solar thermal systems to their gas heating?
Is it because they have to comply with the energy saving regulations?
Wrong, you are allowed to skip solar thermal if other measures reduce energy consumption by at least 15%.
Example:
I’m planning a KfW-55 house with gas heating, solar thermal, controlled ventilation with heat recovery, and excellent insulation.
Now I remove the solar thermal system. What happens?
I lose the KfW-55 status and end up with KfW-70, so I lose a €2,500 subsidy. But I save €6,000 by not installing solar thermal. The operating costs increase by €50 per year due to the missing solar thermal, which adds up to €1,000 over 20 years. So overall, I still save €2,500.
Savings:
€6,000 saved by not installing solar thermal*
- €2,500 lost KfW-55 subsidy
- €1,000 higher operating costs due to no solar thermal*
=======
€2,500
Sounds like an attractive alternative, or is there a major calculation mistake somewhere?
The whole calculation would also apply to a KfW-85 house, which would qualify as a KfW-100 house without the solar thermal.
Best regards
jx7
PS:
Please don’t bring up heat pumps or pellet heating; this is not meant to start a fundamental debate about gas versus heat pumps (with sharp increases in energy prices, heat pumps will eventually become more cost-effective). The initial question is simply: "If using gas, then maybe without solar thermal?"
* Source: xxx-Heizungsvergleich-de "Gas + 5sqm solar thermal"
ErikErdgas schrieb:
but that they can contribute more or less significantly to covering the demand,Before or after the investment costs for the solar thermal system have been recovered? Just work through an example, it doesn’t have to be exact to the cent...
I would like to add to that. If the building application is submitted this year, do the rules discussed here apply? What exactly is needed to get certification that the building is 15% below the minimum requirements of the energy saving ordinance? Or rather, what costs arise from this?
We are currently also leaning towards gas and would prefer to avoid solar if possible.
We are currently also leaning towards gas and would prefer to avoid solar if possible.
B
Bauexperte24 Nov 2015 11:57sirhc schrieb:
If the building application is still submitted this year, do the rules discussed here apply?Yes. But forget the idea that you can still submit the building application this year; that will definitely not happen.sirhc schrieb:
What exactly is required to get certification that you are 15% below the minimum requirements of the Energy Saving Ordinance? Or rather, what costs does this cause?Your building partner should be able to give you information about the costs; it depends on the house. The KfW only requires proof on the front of form 153 and, after completion of the construction work, confirmation that KfW 70 was actually achieved.Regards, Bauexperte
Thank you, Bauexperte. Why do you think it won’t be possible to submit it this year? Although you might be saying that because I mistakenly said building permit / planning permission. In our case, it’s about an exemption procedure according to § 67 of the NRW Building Code. We want to complete that this year.
B
Bauexperte24 Nov 2015 12:25sirhc schrieb:
Thank you very much, Bauexperte. Why do you think it won’t be possible to submit this year? Although you might say that because I mistakenly called it a building application. We are actually dealing with an exemption procedure according to § 67 of the NRW Building Code. We want to complete this within the year. Today is November 24, 2015 – to apply for either a building permit or an exemption procedure, you need a preliminary site plan. Ask a surveyor when they think they can deliver this to you.
Then all architects are unavailable until the jawline (a German expression meaning “totally unavailable”), because Christmas is suddenly just around the corner; and just yesterday it was announced that the energy-saving ordinance is changing.
You also don’t really have time until December 31, 2015 – “between the years” the building authority works as much or as little as the private sector does.
Regards, Bauexperte
Ok - in our case, it appears that the site plan does not need to be created by a surveyor or is already available. The required documents are being prepared by family members and their contacts (these include a civil engineer, draftsman, and architect), all of whom have confirmed that this will be completed within this year. We will know more in four weeks whether it has actually worked out.
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