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.
Yes, and not just the pump power. To determine an accurate annual performance factor for the entire system, storage and pipe losses as well as the electricity consumption for auxiliary heating with heating rods, etc., must also be included. Considering only the heat exchanger does not make sense.
Separate electricity meter before the pump (so everything that consumes power from the unit) and heat meter in the circuit. This is used to determine the annual performance factor.
Storage heat losses are completely irrelevant – or has anyone ever seen losses accounted for through the heating surfaces anywhere?
...
Storage heat losses are completely irrelevant – or has anyone ever seen losses accounted for through the heating surfaces anywhere?
...
T
T_im_Norden29 Apr 2020 16:00What do people always want with storage for photovoltaic systems?
As long as it isn’t heavily subsidized, it’s not cost-effective.
As long as it isn’t heavily subsidized, it’s not cost-effective.
T_im_Norden schrieb:
Why do people always want a battery storage for photovoltaic systems?
As long as it is not heavily subsidized, it does not pay off.Not everyone is solely focused on purely economic benefits. I think the key word is energy independence. For many, it is probably also ecology, even though they might be mistaken in the case of lithium-ion batteries...
This is actually quite simple. It sounds fantastic. The electricity comes from the roof and is stored in the battery so I can use it at night. Great! And if you then get an offer from Solrfred that includes a profitability calculation, you might already start chilling the champagne, that’s how good it looks. Awesome, a 9.2% annual return on a €23,000 (about $25,000) solar system with battery storage. And on top of that, I’m also saving the planet because it’s so eco-friendly and I’ll save 49 tons of CO2 over 25 years. That’s enough carbon savings for me and my wife to fly to Vancouver and back five times with a clear conscience.
But when you start digging deeper, you realize it might not be that great after all. And there’s no way my photovoltaic battery system will ever be able to cover the ground source heat pump, which just takes free heat from the air and also comes with an impressive savings calculation. Well, and it’s also true that neither batteries nor solar panels are made from fine dust (particulate matter). Like I said, that’s how my thought process goes. To be honest, I still find the solution of photovoltaic + storage + heat pump fascinating. It’s just that I’ve read a bit too much skepticism now, and I haven’t found anyone yet who can provide me with a solid calculation of how such a system would perform for me.
Anyway, @T_im_Norden, I’m glad you’re so clever and already know all this, and I’m sorry if people like me, who are just starting out on their journey to all-encompassing knowledge, bother you with their lack of expertise.
But when you start digging deeper, you realize it might not be that great after all. And there’s no way my photovoltaic battery system will ever be able to cover the ground source heat pump, which just takes free heat from the air and also comes with an impressive savings calculation. Well, and it’s also true that neither batteries nor solar panels are made from fine dust (particulate matter). Like I said, that’s how my thought process goes. To be honest, I still find the solution of photovoltaic + storage + heat pump fascinating. It’s just that I’ve read a bit too much skepticism now, and I haven’t found anyone yet who can provide me with a solid calculation of how such a system would perform for me.
Anyway, @T_im_Norden, I’m glad you’re so clever and already know all this, and I’m sorry if people like me, who are just starting out on their journey to all-encompassing knowledge, bother you with their lack of expertise.
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