ᐅ Combination of air-to-air heat pump, air-to-water heat pump, solar thermal system, and photovoltaic system with storage
Created on: 29 Sep 2020 14:57
K
KevinHoehne
Hello everyone,
I hope I’m in the right subforum.
About my project:
My wife and I plan to build a new house (expected start spring 2021) with a KfW55 energy standard. The usable floor area will be approximately 209m² (2250 sq ft) plus a basement.
Our builder includes heating and domestic hot water via an air-to-water heat pump and an air-to-air heat pump, both with a fresh air system including a heat exchanger. Additionally, we decided on a 6 kWp photovoltaic system with a 6.5 kWh battery storage (available as a "spring offer" for about €10,000).
Since I’m generally someone who tries to avoid unnecessary costs (in this case electricity costs for hot water), I’ve been considering having a solar thermal system installed as well. Without the photovoltaic system, I expect savings of around €200 per year (about 800 kWh/year for hot water). If our household grows in the future, the savings would naturally increase.
In our last conversation with the architect, he was convinced that it would make more financial sense to increase the photovoltaic system to 8 kWp (additional cost approximately €5,000) instead of installing the solar thermal system. He couldn’t provide a price for the solar thermal system because it’s not listed in the price catalog, but I assume it would be a similar amount.
Now to my questions:
a) Does anyone have experience with similar energy system combinations?
b) Are there resources or services where one can have such calculations done?
Thank you in advance and best regards,
Kevin
I hope I’m in the right subforum.
About my project:
My wife and I plan to build a new house (expected start spring 2021) with a KfW55 energy standard. The usable floor area will be approximately 209m² (2250 sq ft) plus a basement.
Our builder includes heating and domestic hot water via an air-to-water heat pump and an air-to-air heat pump, both with a fresh air system including a heat exchanger. Additionally, we decided on a 6 kWp photovoltaic system with a 6.5 kWh battery storage (available as a "spring offer" for about €10,000).
Since I’m generally someone who tries to avoid unnecessary costs (in this case electricity costs for hot water), I’ve been considering having a solar thermal system installed as well. Without the photovoltaic system, I expect savings of around €200 per year (about 800 kWh/year for hot water). If our household grows in the future, the savings would naturally increase.
In our last conversation with the architect, he was convinced that it would make more financial sense to increase the photovoltaic system to 8 kWp (additional cost approximately €5,000) instead of installing the solar thermal system. He couldn’t provide a price for the solar thermal system because it’s not listed in the price catalog, but I assume it would be a similar amount.
Now to my questions:
a) Does anyone have experience with similar energy system combinations?
b) Are there resources or services where one can have such calculations done?
Thank you in advance and best regards,
Kevin
KevinHoehne schrieb:
The roof faces south with a pitch of 25° – I know it’s not ideal, but the gable height is limited by building regulations. With steeper roofs, fitting two full floors becomes difficult.
The system will have 24 modules each with 340 heat pumps. The next upgrade from the manufacturer is 10 kWp, but those apparently no longer fit on the roof (~12 m (39 ft) ridge length x 5 m (16 ft) rafter length). You have an almost ideal south-facing orientation, and the roof pitch is close to optimal. In your position, I would try to maximize coverage on the south side. If only 24 modules fit, consider using higher-power modules (for example, ones with 380 heat pumps) or inquire about modules in different sizes. Due to the shallow roof pitch, the north side might also be worth considering; I would at least have that simulated. It’s unlikely you will find a better deal on a photovoltaic system than as part of a new build.
dhd82 schrieb:
You won’t find a photovoltaic system cheaper than when installed as part of a new build.Why? Because of the scaffolding?
All the solar installers I've contacted only wanted to start after the house was already built.
K
KevinHoehne7 Dec 2020 15:25Yes, I had already considered the north side as well. Or a south-facing facade system for the winter – worth considering just for the appearance 😀
There will definitely be two empty conduits installed, so the north side can be easily retrofitted later.
There will definitely be two empty conduits installed, so the north side can be easily retrofitted later.
The scaffolding will remain in place after the shell construction until the exterior walls are finished (plastering / cladding). During this time, the solar installer can start working at the latest.
If you are installing a very large photovoltaic system and, for example, have planned a roof covering with clay tiles, you might consider downgrading to concrete tiles. This saves money and, in the end, you won’t see much difference anyway.
Our photovoltaic system will have a capacity of 26.6 kWp, so there won’t be much visible of our expensive clay tiles. If I had known this in advance, I would definitely have chosen cheaper roof tiles.
If you are installing a very large photovoltaic system and, for example, have planned a roof covering with clay tiles, you might consider downgrading to concrete tiles. This saves money and, in the end, you won’t see much difference anyway.
Our photovoltaic system will have a capacity of 26.6 kWp, so there won’t be much visible of our expensive clay tiles. If I had known this in advance, I would definitely have chosen cheaper roof tiles.
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nordanney7 Dec 2020 15:43Tolentino schrieb:
But do you really need a full scaffolding? Or is the scaffolding for the solar system really that expensive?Definitely much more expensive than if you can use the scaffolding that’s already in place. Then it’s just a few hundred euros, but with that you could, for example, buy something nice for the garden.Similar topics