For our new build, we originally planned to install an air-source heat pump and generate the electricity for it, as well as part of our other electricity needs, with our own photovoltaic system and battery storage. After receiving two quotes, we now have some doubts. The lowest quote for a heat pump with 5.08 kW, a photovoltaic system with 5.1 kWp, and a battery with 5.12 kWh is €33,000. Should we rather choose a conventional gas heating system instead? That would definitely be cheaper. Or is that completely outdated now?
I am someone who no longer considers a gas heating system appropriate for new construction.
Have the heat pump and photovoltaic system offered separately.
As already mentioned, it’s better to go for a larger photovoltaic system and only install a battery storage if you receive substantial subsidies to cover a significant part of the cost; otherwise, the storage doesn’t make much sense yet.
Gas will become significantly more expensive (electricity possibly too), but with a sufficiently large photovoltaic system, you can partially generate your own electricity.
And, of course, insulate the house well—better than the minimum requirements. This will definitely pay off over the next 30 years and beyond, especially now with the high KFW subsidies.
Have the heat pump and photovoltaic system offered separately.
As already mentioned, it’s better to go for a larger photovoltaic system and only install a battery storage if you receive substantial subsidies to cover a significant part of the cost; otherwise, the storage doesn’t make much sense yet.
Gas will become significantly more expensive (electricity possibly too), but with a sufficiently large photovoltaic system, you can partially generate your own electricity.
And, of course, insulate the house well—better than the minimum requirements. This will definitely pay off over the next 30 years and beyond, especially now with the high KFW subsidies.
Specki schrieb:
Gas will become significantly more expensive (electricity possibly as well) Why?
Specki schrieb:
And of course, insulate the house well, better than required; that will definitely pay off over the next 30 years and beyond How do you calculate the break-even point for the insulation measures? Do the costs for the embodied energy of the insulation materials also factor in? The mentioned period exceeds the service life of most heat pumps and gas boilers, and in some cases, it even goes beyond the lifespan of solar panels, both crystalline and amorphous. Is reinvestment taken into account?
If you are referring to external thermal insulation composite systems (ETICS), are the costs for renovation cycles (depending on the manufacturer every 10 to 15 years) considered?
T
T_im_Norden6 May 2020 07:45How large do you want the photovoltaic system to be in order to generate enough electricity for a heat pump during autumn/winter/spring?
The 5 kW (5 kW) photovoltaic system considered here will certainly not be sufficient for that.
I don’t feel confident telling someone that gas or electricity will become significantly more expensive or cheaper, and then having them make a decision between gas and electricity based on that.
The 5 kW (5 kW) photovoltaic system considered here will certainly not be sufficient for that.
I don’t feel confident telling someone that gas or electricity will become significantly more expensive or cheaper, and then having them make a decision between gas and electricity based on that.
MayrCh schrieb:
Why? Because it decreases, due to higher taxes on it, etc.
MayrCh schrieb:
How do you calculate the break-even point for insulation measures? It’s actually quite simple. A house with insulation X requires a certain amount of heat, and a house with insulation Y requires a different amount. You can then compare when the better-insulated house, which has more expensive insulation but lower heat demand, becomes financially advantageous. Of course, there are some uncertainties involved, since no one can predict exact future prices. But ultimately, it pays off. We’re talking about new buildings here, where a few extra centimeters of insulation don’t make a big difference financially. It’s different with renovations, where it might only be worthwhile if you’re already planning to refurbish the façade.
MayrCh schrieb:
The period mentioned above exceeds the service life of most heat pumps and gas heating systems and, in some cases, even the lifespan of solar panels, both crystalline and amorphous. So what? When the heating system reaches the end of its service life, are you going to rebuild your entire house? Sorry, I don’t understand that argument. Besides, the photovoltaic (PV) system is not only for the heat pump. It also saves electricity costs overall and, according to current legal regulations, even generates a small income.
MayrCh schrieb:
If you’re thinking of Exterior Insulation and Finish Systems (EIFS/External Wall Insulation), have you considered the renovation cycles costs (depending on the manufacturer every 10–15 years)? What exactly needs to be done to an EIFS after 10–15 years? It doesn’t necessarily even need repainting. The same maintenance would probably apply to other types of façades as well. Also, it doesn’t have to be EIFS — it could be a ventilated façade, thicker bricks, etc. You should just consider what makes the most ecological sense.
MayrCh schrieb:
Do these costs include the embodied energy of the insulation material? Here again, you should naturally choose the most ecological insulation material possible.
I know this topic tends to be a matter of opinion. But I think it’s worth it! Especially with the current subsidies! By the way, companies are well informed about the subsidies. I suspect the additional costs from a KFW70 to KFW55 or to KFW40 house wouldn’t be as high without the subsidies. Of course, this leads to some additional markups.
Specki schrieb:
It’s actually quite simple. A house with insulation X requires a certain amount of heat, and a house with insulation Y requires a different amount of heat. I did it that way with my new build five years ago. The additional cost from KfW 70 to KfW 55 at that time was €15,000, with an estimated annual energy cost saving of about €100. You can calculate the payback period yourself now.
I’ve excluded the repayment grant and the interest rate benefits from back then, but your argument was that insulation pays off after 30 years. When you compare additional costs and potential savings—both back then and now (excluding repayment grants and interest benefits)—that simply isn’t the case.
Specki schrieb:
Because it decreases, Do you mean less supply or less availability?
If fossil fuel heating systems are no longer installed in about ten years, there will definitely be a change on the demand side from that point onward. In the medium to short term, the commissioning of Nord Stream II will have a significant impact on supply. Around the soon-to-be decommissioned nuclear power plants, numerous combined cycle gas power plants are currently in the approval process. These will also affect demand. At the moment, I don’t get the impression that Russia intends to restrict gas supply in the medium term; we’re still not dependent enough yet.
I believe a heating system must suit the house and should not cost more than necessary overall. The fact is, a gas heating system is still up-to-date nowadays and also significantly cheaper to install. Over a 30-year period, it does not really matter which heating system you choose. In the end, the total costs are about the same, but the gas heating system can realistically last 30 years, whereas this is basically not the case for heat pumps.
Here is a small graphic showing the current situation:
The gas price has been stable for quite a while and is now slightly trending upward but still at roughly the same level as 10 years ago. Once Nord Stream II is completed, no price increases are expected at least in the short term, since someone has to take the gas. Storage facilities are, however, full.
Cruise ships are being converted to CNG or newly built with natural gas turbines. Experts expect neither shortages nor rising prices here for decades.
Pessimists once created this infographic. This has not happened, and costs have largely remained stable.
In contrast, electricity prices have been steadily increasing.
Here is a small graphic showing the current situation:
Specki schrieb:Phew... the supply before Corona and even before Nord Stream II already exceeded the demand by far, and this will remain the case for some time.
Because it is decreasing,
The gas price has been stable for quite a while and is now slightly trending upward but still at roughly the same level as 10 years ago. Once Nord Stream II is completed, no price increases are expected at least in the short term, since someone has to take the gas. Storage facilities are, however, full.
Cruise ships are being converted to CNG or newly built with natural gas turbines. Experts expect neither shortages nor rising prices here for decades.
Pessimists once created this infographic. This has not happened, and costs have largely remained stable.
In contrast, electricity prices have been steadily increasing.
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