ᐅ Gas with solar thermal? Or heat pump with photovoltaic? Advice needed
Created on: 5 Feb 2020 08:57
M
Micha8589
Good morning to the forum,
I have been researching heating options for quite some time and have gathered a few opinions, which have only made me more uncertain about my decision. That’s why I thought I’d ask the forum.
My family (2 adults, 1 child) is planning to build the following single-family house at the end of this year or beginning of next year:
Single-family home with pitched roof
Approximately 115 m² (1,237 sq ft)
Solid construction (calcium silicate brick ground and upper floors, brick-clad)
No KFW standard
Building location: southern Mecklenburg
Unfortunately, I can’t provide an energy performance certificate or heating load calculation yet, as the preliminary offer is still being prepared. I am also aware that a general statement can’t really be made since every house and heating behavior is individual.
The construction company advised us to install a modern hybrid heating system consisting of a gas condensing boiler and two solar thermal panels on the roof for domestic hot water, as the initial costs are relatively low (plus installation of the central gas connection), and this technology has proven reliable. The entire house is planned to have underfloor heating. According to the company, they have had very positive experiences with this and consider the technology future-proof. (There is also the idea of a fireplace in the living room.)
On the other hand, I think gas prices will not get any cheaper in the future, and the topic of CO₂ taxes (especially concerning the fireplace) worries me somewhat.
In theory, I would prefer to install a geothermal heat pump combined with a suitable photovoltaic system because this would make me independent of fossil fuels and allow me to heat “off-grid” to a certain extent, depending on efficiency. However, I am hesitant because of the very high initial costs and don’t really know how these compare to operational costs. I also can no longer realistically assess which technology offers the best cost-performance ratio (except for air-source heat pumps).
As you can see, I am completely undecided and hope to get some feedback and expertise from the forum.
Thanks in advance for your replies.
I have been researching heating options for quite some time and have gathered a few opinions, which have only made me more uncertain about my decision. That’s why I thought I’d ask the forum.
My family (2 adults, 1 child) is planning to build the following single-family house at the end of this year or beginning of next year:
Single-family home with pitched roof
Approximately 115 m² (1,237 sq ft)
Solid construction (calcium silicate brick ground and upper floors, brick-clad)
No KFW standard
Building location: southern Mecklenburg
Unfortunately, I can’t provide an energy performance certificate or heating load calculation yet, as the preliminary offer is still being prepared. I am also aware that a general statement can’t really be made since every house and heating behavior is individual.
The construction company advised us to install a modern hybrid heating system consisting of a gas condensing boiler and two solar thermal panels on the roof for domestic hot water, as the initial costs are relatively low (plus installation of the central gas connection), and this technology has proven reliable. The entire house is planned to have underfloor heating. According to the company, they have had very positive experiences with this and consider the technology future-proof. (There is also the idea of a fireplace in the living room.)
On the other hand, I think gas prices will not get any cheaper in the future, and the topic of CO₂ taxes (especially concerning the fireplace) worries me somewhat.
In theory, I would prefer to install a geothermal heat pump combined with a suitable photovoltaic system because this would make me independent of fossil fuels and allow me to heat “off-grid” to a certain extent, depending on efficiency. However, I am hesitant because of the very high initial costs and don’t really know how these compare to operational costs. I also can no longer realistically assess which technology offers the best cost-performance ratio (except for air-source heat pumps).
As you can see, I am completely undecided and hope to get some feedback and expertise from the forum.
Thanks in advance for your replies.
Here in Middle Franconia, according to PVGIS, the photovoltaic system loses about 3% of its annual output in January. This means you will hardly notice it with regard to the heat pump, but that doesn’t mean photovoltaic power is a bad investment over 10 to 15 years—quite the opposite. However, you should forget the idea that the photovoltaic system will noticeably support the heat pump. If, for example, you plan to use a ductless air conditioner or other high-energy consumers in the summer, the energy is practically free.
P
Pinkiponk6 Feb 2020 09:02T_im_Norden schrieb:
I am facing the same question.
... Thank you for the clear summary of the arguments. My husband and I also decided on a gas boiler combined with solar thermal for our new build in 2020.
T_im_Norden schrieb:
My personal tendency is clearly toward gas, although the heat pump concept does spark my curiosity. Yes, it is a wise choice to keep your experimental urge with gas somewhat in check; otherwise, you might find yourself in the newspaper faster than you’d like.
One experience. In August 2017, the plug was connected. It started operation. Gas boiler Junkers Cerapur xyz. Since that moment, nothing. No error messages. Not even touched. It runs, runs, runs. $60 gas per month. House always the same warm. Mature, reliable technology.
At the same time, the neighbor with a Junkers air-to-water heat pump already had the heating specialists several times. Something was not working. Either electricity consumption went out of control, or the house was not warm, or there was hardly any hot water…
At the same time, the neighbor with a Junkers air-to-water heat pump already had the heating specialists several times. Something was not working. Either electricity consumption went out of control, or the house was not warm, or there was hardly any hot water…
Zaba12 schrieb:
In Middle Franconia, according to PVGIS, about 3% of the annual photovoltaic output is lost in January. This means you probably won’t notice much difference regarding the heat pump, but it doesn’t mean that a photovoltaic system is a bad investment over 10-15 years—quite the opposite. However, you should forget the idea that the photovoltaic system will noticeably support the heat pump. If you plan to install, for example, a split air conditioner or other high-energy consumers for the summer, the electricity generated is practically free.You have hot water available all year round, and the storage tank can be efficiently charged or even overcharged with photovoltaic energy around midday. Even during transitional seasons, you can use midday electricity to heat the building.
Nordlys schrieb:
One experience. In August 2017, the plug was connected. The system started. Gas boiler Junkers Cerapur xyz. Since then, nothing else. No error messages. Not even touched. It runs and runs. 60,- gas per month. The house is always equally warm. Mature, reliable technology.
At the same time, a neighbor with a Junkers air-to-water heat pump had several visits from heating specialists. Something always went wrong. Either the electricity consumption was out of control, or the house wasn’t warm, or there was barely any hot water…. Individual cases are always a tricky matter...
I don’t know your energy standard, but with a KfW55 (a building standard for energy efficiency) plus photovoltaic, you can easily manage with half that amount.
hegi___ schrieb:
You have hot water available all year round, and the storage tank can be ideally charged or even overcharged with the photovoltaic system around midday. Even during the transitional seasons, you can use the midday solar power to heat the building.Certainly from the end of March to early October. But I was referring to the darker months when the heat pump’s consumption is highest. You can check PVGIS yourself to see how much solar energy you get in December, January, and February. Here in the south, it’s just under 3% of the annual yield. With a maximum of about 8 kWh per day, does any of that really go towards heating the hot water when you consider other consumers like controlled mechanical ventilation, refrigerator, and everything else running in standby? Even the storage tank itself consumes electricity!However, I can report firsthand starting next week whether the tank fills up. I have a suspicion.
Similar topics