2kw array poor performance

[bigrockcandymountain]

I am looking for some help for a friend that isn't on fieldlines. 

He has just set up a system with 21 pcs 100w 36 cell modules.  They are 3 strings of 7 and feed into a midnite classic 250 charge controller.  He isn't getting much power.  About 1kwh per day max.  We tried them wired 5 in series first and it was no better or worse. 

I haven't been there in person.  He is very new to wiring, but i have asked lots of questions about connections etc. 

I know the 36 cell aren't ideal, but he bought them before i was advising him.
I have asked about tilt, orientation, partial shading etc.

Anything that sticks out at you guys to ask about?

[XeonPony]

Can he take pictures?

angle is absolutely critical as will wiring with the amount of series panels he's doing

[bigrockcandymountain]

Ya i have seen pictures of his connections.  Mostly just push together the mc4 connectors.  These are not old panels.  Like maybe 2 years at most. 

Im not 100% on orientation.  I have stressed the importance more than once, but I am not 100% sure they face south.  Tilt is about 45 degrees wich is almost optimum right now. 

[kitestrings]

You've probably seen the MS sizing tool, but in case not:
[url]www.midnitesolar.com/sizingTool/index.php/url]

Is it possible the site has limitations, (orientation mentioned), or shading?  Or, could it be that they are just not using all of the output, so the batteries are satisfied, and the charges reducing the output as expected?

[MagnetJuice]

If the panels are clean, oriented properly and at the right angle, the only things left are the connections and the size of the wire to the batteries.

I highly suspect the MC4 connections. The connections are one of the main causes of problems in solar installations. A poor connection has high resistance that wastes power. It also produces heat. The heat can be detected with a temperature gun (digital temperature reader) or with an iPhone app.

I don't have a temperature app on my phone, but a friend of mine showed me his phone app and I was impressed as to how sensitive it was.

It would be an inexpensive way to check the connections.

If your friend decides to go that route, he can get a manual temperature gun or he can check for a suitable app here:

https://www.timesofsilicon.com/best-thermometer-apps-for-iphone

And here, they can be downloaded for Android also:

https://www.easytechtrick.org/best-thermometer-apps

Ed

[bigrockcandymountain]

Ok thanks for all the suggestions you guys.  We finally ended up figuring this out.  It has been a month of back and forth. 

The classic charge controller has a mode called u pick % voc and it was set on that at 30% voc.  So it was running the array at about 50v and not able to charge really at all.  I'm not sure how it got set to that.  Default is normal mppt solar mode. 

It was in looking back through the pics he sent me to try to post on here that i came across a screen shot of his charge controller that looked odd and led to the solution.  So in a roundabout way the forum solved the problem anyway.

Thanks for all the replies.  Happy tuesday
Derek

[SparWeb]

You're welcome.  We will put the bill in the mail shortly.  90-day payment terms.

[bigrockcandymountain]

Hmm nothing for free these days. 

[kitestrings]

Good catch I’d say. That’d do it.