8 Panels - expecations

[Forty_Two]

I had 8 panels installed last December. I know that 8 panels is a small number but that's all the south facing roof space I have.

On good clear sunny days in Feb I was regularly getting over 4.5kwh (see attached screen shot) over the past couple of summer months with some really nice sunny days I have never had more than 2.7kwh. Does the winter sun produce better results that the summer sun or have some of my panels failed?

 

[rodrick]

Panels produce better in cooler temps also do you have some shading from tree‘s that now have leaves have you checked your connections it could be many things including temperature

 

[rpdom]

You've got higher capacity panels than me. My 8 are rated at 3kW, but peak at 4kW on a cold sunny day.

As has been said, they perform best when cool and output drops quite rapidly once they heat up - and they can get quite hot in full sun.

Also, if the weather has been dry, could they have dust on them? A bit of rain might clear that off if so.

 

[pollenface]

where is 2.7kwh in your picture?

I am seeing 0kwh export and 3.8kwh yield/consumption.

 

[Forty_Two]

where is 2.7kwh in your picture?

I am seeing 0kwh export and 3.8kwh yield/consumption.

I look at the 5 circles on the right of the screen clip. The yellow circle (top left) I read as that what the panels are producing at that monet in time (4.64kwh) The heading above that circle 'Total Yield 3.8kwh' I read as that as a total product of all the panels thus far that day.

 

[pollenface]

I look at the 5 circles on the right of the screen clip. The yellow circle (top left) I read as that what the panels are producing at that monet in time (4.64kwh) The heading above that circle 'Total Yield 3.8kwh' I read as that as a total product of all the panels thus far that day.

That is my understanding

 

[Mattb4]

Output of panels is in watts or kilowatts. Kilowatt-hours is watts in a hours time.

It is not unusual for lower production for fixed panels near the Summer solstice. Couple that with heat and humidity and what looks like a nice sunny day produces less peak wattage. If your panels are angled to produce best in Winter they likely add to the reduction. Another issue for some folks is Dirty panels. If you have not cleaned them in a long time you might be lowering the amount they can generate.

Not to say that there might not be a connection issue or even a bad panel issue. Does not hurt to periodically check your wires and connectors.

 

[McKravitts]

I'm experiencing the same issue. I was getting more Kw's last winter during a short but sunny day then I'm getting lately even though my panels are positioned more favorable for summer sun.
I believe there are several contributing factors.

Reduction in efficiency due to higher temperatures.
Higher humidity.
The haze from Canadien wild fires.
Tree pollen, mainly Oak and Cotton wood, accumulating on my panels.
The lack of rain that helps keep the panels clean.