ᐅ Photovoltaic System: How Many kWp Are Sufficient for a House?
Created on: 19 Mar 2020 09:10
L
lin0r87
Hello everyone!
We are building a semi-detached house and want to install a photovoltaic system on the roof. The orientation would be south/west and north/east. We intend to use most of the electricity ourselves. A battery is not planned, as the cost is quite high for such a system and it probably doesn’t make financial sense.
We have received an offer that includes:
- 14x IBC MonoSol 360 (there is still space on the north/east side... does that make sense?)
- SMA SB 3.6-1AV-40 inverter
- DEHNcube YPV SCI 2MPP surge protection device
- Meter cabinet (+ accessories)
- Installation
The price is about 7,500€ gross.
The system will have a capacity of 5.04 kWp.
Currently, there are three people living in the house (2 adults, 1 child). Four are planned.
Our roof is quite simple but well oriented.
We are wondering if 5.04 kWp is sufficient?
Our electricity consumption in the apartment was always below 3,500 kWh per year, but we expect it to increase with the house. We estimate about 4,500 kWh.
Regarding the 24/7 electrical loads:
There will be an air-to-water heat pump from Novelan and a ventilation system with heat recovery.
I would really appreciate some advice.
We are building a semi-detached house and want to install a photovoltaic system on the roof. The orientation would be south/west and north/east. We intend to use most of the electricity ourselves. A battery is not planned, as the cost is quite high for such a system and it probably doesn’t make financial sense.
We have received an offer that includes:
- 14x IBC MonoSol 360 (there is still space on the north/east side... does that make sense?)
- SMA SB 3.6-1AV-40 inverter
- DEHNcube YPV SCI 2MPP surge protection device
- Meter cabinet (+ accessories)
- Installation
The price is about 7,500€ gross.
The system will have a capacity of 5.04 kWp.
Currently, there are three people living in the house (2 adults, 1 child). Four are planned.
Our roof is quite simple but well oriented.
We are wondering if 5.04 kWp is sufficient?
Our electricity consumption in the apartment was always below 3,500 kWh per year, but we expect it to increase with the house. We estimate about 4,500 kWh.
Regarding the 24/7 electrical loads:
There will be an air-to-water heat pump from Novelan and a ventilation system with heat recovery.
I would really appreciate some advice.
S
Stefan8907 May 2020 16:58Zaba12 schrieb:
Here is a chart from yesterday without charging the electric car. [ATTACH alt="14B457B5-C000-4DA1-BF48-FBBB14CBFC14.png"]46710[/ATTACH]A good example: you can see that around 9 a.m. the battery is fully charged. And during midday, you would hit the feed-in limit (at 50% limit due to the subsidy).Is it the same for you, that some electricity is still drawn from the grid even though the demand can be fully covered by the battery? I had read about that.
Yes, that's actually the case. But until noon today, it was 62 Wh.
In the screenshot, you can see the electric car charging (green) at 14 A via a Schuko socket, so with 3.2 kWh. Faster or more power isn’t necessary. It will be fully charged after 5 hours.
And what I noticed is that KOSTAL is really bad when it comes to the app and the solar portal.
In the screenshot, you can see the electric car charging (green) at 14 A via a Schuko socket, so with 3.2 kWh. Faster or more power isn’t necessary. It will be fully charged after 5 hours.
And what I noticed is that KOSTAL is really bad when it comes to the app and the solar portal.
You should definitely change your charging management!
The battery should charge around midday. If you exceed the feed-in limit, you will stay below it this way. Otherwise, power is wasted. (As long as you have set the limit to “soft” and have not restricted the inverter accordingly. The SMA SHM can definitely do this as far as I know.)
Also, always make sure the car is not charged from the battery. Otherwise, you first charge the home battery and then the car battery. That results in wasted energy twice.
The battery should charge around midday. If you exceed the feed-in limit, you will stay below it this way. Otherwise, power is wasted. (As long as you have set the limit to “soft” and have not restricted the inverter accordingly. The SMA SHM can definitely do this as far as I know.)
Also, always make sure the car is not charged from the battery. Otherwise, you first charge the home battery and then the car battery. That results in wasted energy twice.
S
Stefan8907 May 2020 17:53Zaba12 schrieb:
Yes, that’s actually the case. But until noon today, it was 62Wh. Could you please check how much that amounts to in a full day?Zaba12 schrieb:
And what I noticed is, KOSTAL’s app and solar portal are really poor.
[ATTACH alt="0BB8EEA5-B5DE-4CDD-BB92-A77BD52B1E04.jpeg"]46711[/ATTACH] Yes, for me the display in the portal/app is often delayed by 12 hours. However, a completely new portal is planned for June/July. I’m curious and hopeful for improvements.Specki schrieb:
You definitely need to change your charging management!
The battery should charge around midday. If you go over the feed-in limit then, you stay below it. Otherwise, you’re wasting electricity. (As long as you have the limit set “soft” and haven’t limited the inverter accordingly. The SMA SHM can definitely handle this as far as I know.)
And always make sure the car is not being charged from the battery. Otherwise, you’re first charging the home battery, then the car battery. That’s wasted energy twice over. Please explain that in simple terms. The inverter is soft limited, whatever that means. Usually, without a curfew or Corona restrictions, the car is charged starting at 5 p.m. At that time, the battery is still full, and yes, unfortunately, I will have to charge from the battery if the photovoltaic system doesn’t produce enough. That’s just how it is and can’t be changed. After all, you don’t wait two weeks to refuel if fuel is 20 cents cheaper per liter—cool.
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