We have a groundwater heat pump, an electric heating element for hot water, and a 10 kW solar system with a 25 kWh (27 kWh) battery storage.
Now in winter, the solar system produces practically nothing. The electricity demand is supplied from the grid.
The system shows the daily electricity consumption.
What I don’t understand about these curves is the electricity demand around 4:00 AM. At that time, we are sleeping, and except for the heat pump, no electricity should be needed. I am not aware of any timer switch that turns anything on at that time.
What could that be?
Best regards,
Bernd
Now in winter, the solar system produces practically nothing. The electricity demand is supplied from the grid.
The system shows the daily electricity consumption.
What I don’t understand about these curves is the electricity demand around 4:00 AM. At that time, we are sleeping, and except for the heat pump, no electricity should be needed. I am not aware of any timer switch that turns anything on at that time.
What could that be?
Best regards,
Bernd
D
DaGoodness17 Dec 2023 22:07In June, for example, I had 1539 kWh.
The system produces about 12,000 kWh per year. It has been running for 3 years now.
And since you mentioned the investment costs: for the 10 kWh system, I paid €9,000 net.
If you think this sounds like a fairy tale, that’s your problem. These are the actual figures.
The system produces about 12,000 kWh per year. It has been running for 3 years now.
And since you mentioned the investment costs: for the 10 kWh system, I paid €9,000 net.
If you think this sounds like a fairy tale, that’s your problem. These are the actual figures.
B
Buchsbaum17 Dec 2023 22:22Your numbers don’t add up.
My photovoltaic output in June was 900 kWh with a 7.5 kWp system. Your system with 10 kWp produced 1539 kWh. That could be possible.
But today I only had 3.5 kWh. If you had over 21 kWh today, then in summer you should be producing around 200 kWh per day.
That would mean about 6000 kWh per month. None of this matches.
It’s generally estimated that in December you get about 10 percent of the output compared to June or July. That fits for me, but unfortunately not for you.
You can claim whatever you want, that you get 20 percent output in December compared to July values.
My photovoltaic output in June was 900 kWh with a 7.5 kWp system. Your system with 10 kWp produced 1539 kWh. That could be possible.
But today I only had 3.5 kWh. If you had over 21 kWh today, then in summer you should be producing around 200 kWh per day.
That would mean about 6000 kWh per month. None of this matches.
It’s generally estimated that in December you get about 10 percent of the output compared to June or July. That fits for me, but unfortunately not for you.
You can claim whatever you want, that you get 20 percent output in December compared to July values.
D
DaGoodness17 Dec 2023 22:31What’s wrong with that?
Today was a very sunny day here. Apparently, not so much where you are. We often have sunny days in winter here.
In summer, around 60 to 70 kWh per day are possible.
I can’t quite understand how you arrive at 200 kWh, but I can assure you that my figures are accurate.
Whether you believe it or not doesn’t really matter to me. 😉
Today was a very sunny day here. Apparently, not so much where you are. We often have sunny days in winter here.
In summer, around 60 to 70 kWh per day are possible.
I can’t quite understand how you arrive at 200 kWh, but I can assure you that my figures are accurate.
Whether you believe it or not doesn’t really matter to me. 😉
K
KarstenausNRW17 Dec 2023 22:43DaGoodness schrieb:
Today we had 21.8 kWh. I’m really shocked! I live in the same area – Lower Rhine/Rhineland. With the identical system, I only got 8.2 kWh production. Crying…. Was the sun out earlier where you are? Here it was still cloudy in the morning.
Buchsbaum schrieb:
For the months from November to February, a consumption of 50 kWh daily is completely normal. Honestly, that’s total nonsense – at least without an electric car. With an electric car and about 400–500 kWh consumption per month, I’m at 850–1,200 kWh during the period you mentioned. Working from home, waterbed, heat pump, electric car = 30–40 kWh daily. Without the electric car, daily consumption is 30–50% lower.
I also don’t see how a normal household could use 2 kWh per hour. Even in an older house with a heat pump but no insulation, that would be very difficult.
DaGoodness schrieb:
For example, in June I had 1,539 kWh.
The system produces about 12,000 kWh per year. It’s been running for 3 years now. What kind of system and orientation do you have? With a south-southwest (SSW) orientation, I only manage 1,428 kWh in June and about 10,000 kWh per year (but this year was pretty bad). I definitely can’t reach 70 kWh per day. Do you have a 10 kW inverter running without throttling? Three years ago the 70% rule still applied, so 70 kWh per day shouldn’t have been possible.
The price was reasonable at that time – I paid about the same.
D
DaGoodness17 Dec 2023 22:50I am located west of Cologne.
The 10 kWp system is oriented directly south with a 45-degree roof pitch. It produces a lot in winter.
Fortunately, I never had the 70% throttling applied.
The 10 kWp system is oriented directly south with a 45-degree roof pitch. It produces a lot in winter.
Fortunately, I never had the 70% throttling applied.
X
xMisterDx18 Dec 2023 00:16Unbelievable. You have to be nearly brain-dead to argue about the purpose, meaning, and sizing of a photovoltaic system based on its daily performance, especially in winter.
It’s like two diesel drivers arguing who drove better on the A2 highway... one going 100 km/h (60 mph) alone and empty, the other going 180 km/h (110 mph) fully loaded. That’s the (intellectual) level being shown here right now.
This (good) reason is exactly why statistics exist. They provide us with average values over many years... And those averages clearly show that in December you can only expect around 15% of the output you get in July from photovoltaic systems. The fact that MyGoodness had one day with higher output... neither the statistics nor anyone except MyGoodness and RotorMotor care about that.
Also, the claim that a 45° south-facing angle is optimal is incorrect. You get 100% output facing south at 28°. If you’re going to nitpick and call others fools, MyGoodness...
It’s like two diesel drivers arguing who drove better on the A2 highway... one going 100 km/h (60 mph) alone and empty, the other going 180 km/h (110 mph) fully loaded. That’s the (intellectual) level being shown here right now.
This (good) reason is exactly why statistics exist. They provide us with average values over many years... And those averages clearly show that in December you can only expect around 15% of the output you get in July from photovoltaic systems. The fact that MyGoodness had one day with higher output... neither the statistics nor anyone except MyGoodness and RotorMotor care about that.
Also, the claim that a 45° south-facing angle is optimal is incorrect. You get 100% output facing south at 28°. If you’re going to nitpick and call others fools, MyGoodness...
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