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theundertaker30 Mar 2021 17:34Hello,
We are planning to build a house, hopefully by the end of the year, and I have already started considering the type of heating system.
It will be a single-family home of about 150sqm (1,615 sq ft) located near Bremen. Currently, there are two of us, but a child will be arriving soon.
After several hours of research on Google and forums, I believe that an air-source heat pump combined with a photovoltaic system and battery storage is the most practical solution. For coziness, a stove is also planned for the living/dining area.
Advantages: no costs for gas connection or gas supply, no expenses for drilling and permits, increased efficiency through self-generated electricity with storage, and you can earn money by feeding surplus energy into the grid. Also, it provides some cooling effect in the house during summer.
Disadvantages: higher initial investment compared to a gas heating system, increased electricity costs in winter when it gets really cold.
My main concern is whether the higher electricity consumption might offset the savings from not using gas. Are there other disadvantages I might have overlooked?
How much more expensive is a photovoltaic system with a battery approximately compared to a conventional gas heating system?
Does the stove support the heating system in any way, or does the heating system maintain its temperature regardless of how warm the room gets?
We are planning to build a house, hopefully by the end of the year, and I have already started considering the type of heating system.
It will be a single-family home of about 150sqm (1,615 sq ft) located near Bremen. Currently, there are two of us, but a child will be arriving soon.
After several hours of research on Google and forums, I believe that an air-source heat pump combined with a photovoltaic system and battery storage is the most practical solution. For coziness, a stove is also planned for the living/dining area.
Advantages: no costs for gas connection or gas supply, no expenses for drilling and permits, increased efficiency through self-generated electricity with storage, and you can earn money by feeding surplus energy into the grid. Also, it provides some cooling effect in the house during summer.
Disadvantages: higher initial investment compared to a gas heating system, increased electricity costs in winter when it gets really cold.
My main concern is whether the higher electricity consumption might offset the savings from not using gas. Are there other disadvantages I might have overlooked?
How much more expensive is a photovoltaic system with a battery approximately compared to a conventional gas heating system?
Does the stove support the heating system in any way, or does the heating system maintain its temperature regardless of how warm the room gets?
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nordanney30 Mar 2021 18:04theundertaker schrieb:
After some hours of googling and reading forums, I believe that an air-source heat pump + photovoltaic system + battery storage is the most practical solution. For coziness, a stove is also planned in the living/dining area. Why do you think so? You probably mean an air-to-water heat pump.
theundertaker schrieb:
Advantages: no costs for gas connection and gas supply, no costs for the whole drilling process and permits, etc. Through electricity generation with storage, efficiency increases and you even get paid for feeding electricity into the grid. Cooling effect inside the house during summer. Please don’t expect miracles in winter. You still need electricity for heating, but the sun isn’t shining then. Storage itself is not bad, especially if it is subsidized or if you, for example, own an electric car.
Photovoltaics alone almost always pay off—install as much as possible on the roof.
You can forget about the cooling effect. Even with geothermal energy, it doesn’t cool in the peak of summer, not even really cools down.
theundertaker schrieb:
Disadvantages: higher upfront costs compared to gas heating, increased electricity costs in winter if it gets really cold. Higher upfront costs? No.
Increased electricity costs in winter – yes, that’s true. But you would also have higher gas costs in winter.
theundertaker schrieb:
Actually, I’m just unsure whether the higher electricity consumption might cancel out the savings from not having gas at all? Are there other disadvantages I haven’t considered? One thing you haven’t considered is: What kind of house are you building? And your usage habits. I can have a 120sqm (1300 sq ft) low-energy house with €1000 electricity costs (windows wide open and 25°C (77°F) indoors) or €300 heating costs (just 21°C (70°F) and proper ventilation).
theundertaker schrieb:
How much more expensive is a system with photovoltaics + battery roughly compared to a conventional gas heating system? How much more does a green car cost than a red one? Don’t separate photovoltaics from the equation. It makes sense with gas heating too.
theundertaker schrieb:
Does the stove support the heating somehow, or does the heating system keep its temperature regardless of how warm the room gets? In new houses with underfloor heating, the temperature is always even, regardless of how the heat is generated. Of course, a stove provides additional heating. But there are different types of stoves you can install—some store heat, others are just for ambiance.
Take your time and read up here in the forum.
Without a gas connection and unless you live in high mountains, I would choose a heat pump. If possible, go for geothermal. Always install photovoltaics.
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knalltüte30 Mar 2021 18:11However, you also have increased electricity costs for cooling in the summer with an air-to-water heat pump (a ground-to-water heat pump could provide passive cooling), or with an air-to-air heat pump (essentially an "air conditioner," which consumes a lot of electricity whenever it runs).
The fact is, a storage battery is not financially worthwhile simply to increase self-consumption. If you want to do it for ecological reasons... by all means (there are different calculations on this).
I hope I have summarized this correctly; as always, this is an amateur opinion without any guarantee.
The fact is, a storage battery is not financially worthwhile simply to increase self-consumption. If you want to do it for ecological reasons... by all means (there are different calculations on this).
I hope I have summarized this correctly; as always, this is an amateur opinion without any guarantee.
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theundertaker30 Mar 2021 19:40
theundertaker wrote:
After several hours of googling and browsing forums, I believe that an air-source heat pump + photovoltaic system + battery storage is the most practical solution. For comfort, a stove is also planned in the living/dining area.
Why do you think that? You probably mean an air-to-water heat pump.Yes, that’s right.
theundertaker wrote:
Advantages: no costs for gas connection and gas supply, no expenses for the entire drilling process and permits, etc. The efficiency increases thanks to electricity generation with storage, and you even get paid for feeding electricity back into the grid. Cooling effect inside the house in summer.
Please don’t expect miracles in winter. You need electricity for heating, but the sun won’t always be shining. Having a battery storage is not bad, especially if it’s subsidized or if, for example, you have an electric car. Photovoltaics alone almost always pay off — cover the entire roof.
Forget about cooling effects. Even with geothermal heat, it doesn’t cool the house in high summer, not even really noticeably cooler.
Currently, we live in a house built in the 1960s or so, with no insulation; after a hot summer day over 30°C (86°F), the house stays just as warm inside...
I’m not expecting a constant 19°C (66°F), but if the house could only warm up to 25°C (77°F), that would already be a bit more comfortable. 🙂
theundertaker wrote:
Disadvantages: higher upfront costs compared to gas heating, increased electricity costs in winter when it’s really cold.
Higher upfront costs? No. Increased electricity costs in winter — yes, that’s true. But during winter, you also have higher gas bills.
theundertaker wrote:
Actually, I’m only unsure whether the higher electricity consumption might offset the savings from having no gas. Are there other disadvantages I haven’t considered?
There’s one thing you haven’t considered: what kind of house are you planning to build? And how will you be using it? I can heat a 120sqm (1290 sq ft) KfW 40 house with €1000 electricity (windows wide open and 25°C (77°F) inside) or with €300 heating costs (only 21°C (70°F) and proper ventilation).The house should at least meet KfW 55 standard — is the difference to KfW 40 only in the technology (solar, heat recovery) or also in better insulation?
theundertaker wrote:
How much more expensive is a system with photovoltaics + battery roughly compared to a conventional gas heating system?
What does a green car cost compared to a red one? Don’t separate photovoltaics from the heating system. It makes sense with gas heating as well.
theundertaker wrote:
Does the stove support the heating system in any way, or does it maintain its temperature regardless of how warm the room gets?
In new houses with underfloor heating, the temperature is always stable regardless of the heat source. Of course, a stove adds extra warmth. But there are different options for stoves as well — either heat storing or just for “fun.”Take your time to read through the forum here.
If you don’t have a gas connection and don’t live in a high-altitude area, I would choose a heat pump. If possible, go for geothermal. Always put photovoltaics on the roof.
A gas connection costs about €1330 gross up to 30m (about 100 feet), but the house will probably be 100m (330 feet) from the street, so it will be more expensive, I guess.
Winters here in the north are usually mild, and continuous subzero temperatures have been rare in recent years.
What’s better about geothermal? In winter, you don’t need electrical backup heating, but what about other times?
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theundertaker30 Mar 2021 19:47superzapp schrieb:
However, you also have higher electricity costs for cooling in the summer with an air-to-water heat pump (a ground-source heat pump could provide passive cooling), or an air-to-air heat pump (basically an air conditioner = high electricity consumption whenever it runs).
In summer, however, a lot of electricity is produced by the photovoltaic system, so this should balance out somewhat (with an air-to-water heat pump).
The fact is, a storage battery does not financially pay off just to increase self-consumption. If you want to do it for ecological reasons... sure (there are different calculations on this).
Financial reasons are usually the main consideration, but when I look for such batteries, they are already available starting at around 2,000–3,000 € (euros).
I hope I’ve summarized this correctly, as always, this is a layperson’s opinion without guarantee. Similar topics