aviateur17
New Member
Thanks all for your replies. I'm going to figure out if I try the Enphase inverters rated for higher power or buy the communication gateway (Envoy) or both. Appreciate the help!
Solved: Limited IQ8+ inverter output - JA Solar panels rated for 395 Watts putting out 250 watts (63% of max rated)
- Thread starter aviateur17
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aviateur17
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aviateur17
New Member
Thanks, do you think removing those is going to make a big difference? I can certainly do that but I'm curious what you think will happen when I do?
It should. When testing panel output you don't want any kind of shade on cells. Remove those leafs from bottom corner as well. Do you have haze or sky is perfectly clear?
aviateur17
New Member
Sky is perfectly clear. I'll go out there and take two pictures one of the panels with them removed and one of the sky.
aviateur17
New Member
Due to low angle of the sun in December your maximum solar radiation is roughly half compared to summer. See image below. December has 642 W/m2 maximum compared to summer 1270 W/m2. Your solar panel aperture is 1.95m2 so total solar power that hits the surface is 642*1.95=1254W. Multiply by panels efficiency of 20% and you get 251Wdc per panel. Close enough. [EDIT: This could be horizontal tilt collector data making above assumption wrong.]
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aviateur17
New Member
Thanks, I really appreciate the data and the chart and all of the information. What I can't understand though is the clipping or flat top in the power delivered between 8AM and 4PM. I would expect to see the peak power around noonish and then lower power before and after that time but I'm seeing the same amount of power (clipped) between 10AM and 3PM. If the limitation were the sun light from the sun wouldn't the power delivered from 10AM to 3PM vary?
That's likely some issue with your inverters. I would try DC MPPT controller or solar panel tester instead.
Mike 134
Solar Enthusiast
Since it is a ground mount can you post a picture in the Enphase labels?
aviateur17
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Solar Guppy
Red Cobra Guppy
Your issue is the panels only get rated output at ~13 amps being sourced but the Enphase is limited to ~10 amps, this is what is causing the clipping
Also the Maximum AC output is rated ~290W ( 1.21A @ 240V ) but since the panel is not on its mppt peak at 10 amps, it is what it is
Also the Maximum AC output is rated ~290W ( 1.21A @ 240V ) but since the panel is not on its mppt peak at 10 amps, it is what it is
I doubt his panels are generating more than 8A right now due to low solar irradiance.
Solar Guppy
Red Cobra Guppy
The tilt close to perpendicular can get near name plate current this time of year, cooler temps also help with the higher voltage
In Minnesota at 22deg sun angle? Hmm maybe W/m2 data I found was for horizontal tilt collector. Need to check that. Source: http://www.somnwx.com/pages/station/climate.php?var=S
Solar Guppy
Red Cobra Guppy
Panel pictures posted looks to have the panels ~50 to 60 degree tilt which would be close to perpendicular
aviateur17
New Member
I just ordered an AP Systems DS3-L so we'll see how that does in comparison to these IQ8+ inverters.
aviateur17
New Member
Correct, I had them at 21 degrees from perpendicular and they were putting out the same power as they are now at 45 degrees from perpendicular. I know the angle is not ideal but I'm just doing this for testing purposes.
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