How to connect a mismatch of panels and equipment (A little complex)

[keaton85]

This is what I have at my disposal currently:

24V system
Panels:
4X SW315 XL panels
4X Siemens SR100
24X Carrizo Gold panels (two cracked panels)

Batteries:
24X T105 making 1,350AH capacity

Charge controller:
Trace C40 PWM
I might be able to get my hands on a MidNite 200 Classic Lite MPPT

Inverter:
Trace SW4024


Location: Outside of Concord, NH

I'm at a loss of how to hook this system up the best way. Any ideas would be great! I can post specs on all panels if need be, although I'm not 100% on the Carrizo panels.

[Mike90250]

Forget trying to use the cracked panels, they will die on you.

[peakbagger]

Darn I have been looking for some SR-100 panels for historical purposes. I think any solution using the SR-100s and the Carrizos is going to cost more than picking up some panels that match up with the newer panels.

[keaton85]

Is it possible to hook up all the old panels to the PWM and all the new panels to the MPPT, then feed that into the battery bank?

[paulcheung]

Is it possible to hook up all the old panels to the PWM and all the new panels to the MPPT, then feed that into the battery bank?

That should work.

[SunEagle]

That should work.

Except he is talking about a bank of 24 T105 batteries. That is 6 parallel strings of 4 in series 6v @ 225Ah batteries.

And if he only uses those 4 x 315w panels that 40amp Trace PWM CC is about maxed out.

[thastinger]

How much power do you require? Seems you could sell some of that equipment and use the money to design a 48V system that is going to be a better fit in the long term.

Those Carrizo Gold panels you have are from the teardown of the Cali plant I assume. These were hot items a few years ago but the salvage company didn't do a great job of packaging them together and because they were used with the mirrors, most of them are severely degraded in output power, which is going to make it difficult for you to use them in strings with their uneven output. Have you tested them for output, if so, you're going to want to group them together. You may only get 500W or less from 20 of those panels together. It is pretty common for a "quad pack" (how they sold them) to put out 75W.

[keaton85]

I am thinking more along the lines of just getting two more of the SW315 XL panels for a total of 6 panels. Cutting the battery bank in half and using just that set-up. A Outback charge controller was purchased, so no more Midnite classic 200.

So:
6X SW315 XL panels
12X T105 making 675Ah bank

Taking all the other panels and and the PWM charger with the other half of batteries and using it for a different system. Unless anyone has any good ideas to use the Siemens SR100 and the Carrizo panels?

Other notes:
- 25% of the panels are shaded in the morning 1-2hrs and afternoon 1-2hrs since they are in the woods and trees shade them.
- Battery bank is about 4yrs old and they are the basic non-RE T105s, which are run down below 50% most days, with no equalizing done. so unknown health on the battery bank.