Are these the same? VOC Temperature Coefficient C° and Temperature coefficient of PMAX

[fafrd]

View attachment 75884

You are more than fine (and have left yourself the headroom to go to a 3S string of those same or similar panels…).

 

[WYtreasure]

And if I up the panels to 6 @ 24v

 

[WYtreasure]

And I will have maxed the Classic 150 at 12 panels & 48 volts, 4380 watts which gives me about 10% over paneling for our normal consumption.

Am I thinking clearly or not so much?

 

[sunshine_eggo]

LOL... those panels should be good on that controller to below absolute zero.

 

[sunshine_eggo]

And I will have maxed the Classic 150 at 12 panels & 48 volts, 4380 watts which gives me about 10% over paneling for our normal consumption.

Am I thinking clearly or not so much?

Crystal.

 

[WYtreasure]

Crystal.

Cool,
I just wish they weren't bobbing around on a ship waiting to be unloaded by a crane operator who doesn't want to get to work.

 

[sunshine_eggo]

Cool,
I just wish they weren't bobbing around on a ship waiting to be unloaded by a crane operator who doesn't want to get to work.

Don't forget all the dock workers and truck drivers that are sleeping on the job too.

 

[WYtreasure]

Here I go again. ?
Trying to interpret the terminology from the Manufacturer so I can enter it correctly in the MidNite Classic Sizing Tool.

The tool wants me to enter this number:
VOC Temperature Coefficient C°
(Default is -0.33%)

The manufacturer offers this number:
Temperature Coefficient Of Voc -(80±10)mV/°C



MidNite's "Default" of -0.33% and the manufacturer's -0.08% seem miles apart.

The manufacturer uses the same numbers for every panel they make, whether it's 10watts or 200watts. Could the numbers be correct?


Did I enter it correctly in the picture below?
The resulting temperature seems outrageous.

 

[sunshine_eggo]

You have switched to much lower voltage panels: 20.23V. 4 in series is only 81V vs. 150V limit.

That panel manufacturer uses a different convention. They're not using a %, they're using absolute voltage. -.08V/°C. So if it's 10°C cooler, the panel is 0.8V higher.

.08V/20.23Voc = .39% - close enough to 0.33% for me as a sanity check

 

[WYtreasure]

You have switched to much lower voltage panels: 20.23V. 4 in series is only 81V vs. 150V limit.

That panel manufacturer uses a different convention. They're not using a %, they're using absolute voltage. -.08V/°C. So if it's 10°C cooler, the panel is 0.8V higher.

.08V/20.23Voc = .39% - close enough to 0.33% for me as a sanity check

Thanks, and Yep, I'm on plan "C" now.
Writing another thread at the moment for the folks at the playground (Beginners Corner).