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.
Stefan890 schrieb:
Could you please check how much that adds up to over a whole day?
Yes, on my portal/app the display is often delayed by 12 hours. However, a completely new portal is supposed to be launched in June/July. I’m curious and hoping for improvements.I can show you tomorrow afternoon, then I will upload the full screenshot from today.You should set the battery charging so that it only starts around 11 o’clock or so.
If your inverter is softly limited, that means it allows more than the 70% limit, but you only feed in 70%. So, let’s say your system produces 90% around midday. Then you lose 20% (90 - 70). However, if you charge your battery during that time, you can use those otherwise lost 20% to charge your battery. And until then, you don’t need it fully charged anyway.
That’s a rough explanation.
Well, that’s the way it is if there’s no other option. But maybe it’s enough if the car only charges between 5 and 6 or 7 p.m., and not after the sun has gone down. Maybe that’s enough to get you through the week, and then you let it fully charge during the day on weekends.
Everyone has to decide for themselves if this “effort” is worth it. In the end, the amount you save isn’t very big. I’d probably do it anyway, because I’m a bit of an eco-friendly person who would even build a KfW40 house. ^^
If your inverter is softly limited, that means it allows more than the 70% limit, but you only feed in 70%. So, let’s say your system produces 90% around midday. Then you lose 20% (90 - 70). However, if you charge your battery during that time, you can use those otherwise lost 20% to charge your battery. And until then, you don’t need it fully charged anyway.
That’s a rough explanation.
Well, that’s the way it is if there’s no other option. But maybe it’s enough if the car only charges between 5 and 6 or 7 p.m., and not after the sun has gone down. Maybe that’s enough to get you through the week, and then you let it fully charge during the day on weekends.
Everyone has to decide for themselves if this “effort” is worth it. In the end, the amount you save isn’t very big. I’d probably do it anyway, because I’m a bit of an eco-friendly person who would even build a KfW40 house. ^^
Specki schrieb:
You should set the battery charging to start around 11 a.m. or so.
If your inverter is softly limited, that means it allows more than 70%, but you only feed in 70%.
So, if your system produces 90% at midday, you lose 20% (90 - 70). But if you charge your battery during that time, you can use this otherwise lost 20% to charge the battery. And until then, you don’t need it fully charged anyway.
That’s a rough explanation.
Well, that’s how it goes if there’s no other option. But maybe it’s enough if the car is only connected from 5 to 6 or 7 p.m., and doesn’t keep charging after the sun goes down. Maybe you get through the week like that and let it fully charge during the day on weekends.
Everyone has to decide for themselves if the effort is worth it. In the end, the amount you save isn’t huge. I’d probably do it anyway because I’m a bit of an environmentalist who would also build a KFW40 house ^^ Thanks, I understand now! Makes sense. Since I have the inverter, I can’t really control the timing. Just checked. But maybe it’s just the mobile version of the portal again.
Google says the SMS inverter has 5 charging windows. Kostal has none; it starts charging as soon as the photovoltaic system is producing. There’s no other option.
S
Stefan8907 May 2020 18:50Attached is my graphic from yesterday: East-West orientation with 9.7 kW. Interestingly, zabas photovoltaic system generates electricity at a similar time.
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