Mix and Match modules

Obbit · Aug 28, 2014

Hey there

I need to replace a broken module on an old install, but the module we used had a silver frame and that model now has a black frame.

I'm looking at using a different brand so it looks the same but I can't find one with exactly the same electrical parameters.

Does anyone know what sort of tolerance would be allowable with this or how I'd work it out?

To clarify:
Existing Yingli 250Wp mono
15.3% eff
30.5 Vpmax
38.1 VoC
8.2 Ip
8.71 Ioc

Replacment
Upsolar 250Wp mono
15.4% eff
30 Vpmax
37.7 VoC
8.3 Ip
8.8 Ioc

Cheers people

BruceB · Aug 28, 2014

The inverter will not know you have a different panel there, it will just hunt up and down the power curve to get to a maximum. So you want a panel with similar characteristics to the others in so that it causes no lumps/bumps on the curve for the mpp tracker to get stuck on. The panel you have found looks like the same technolgy with almost identical maximum power and short circuit currents, so I think it will be fine.

I have no particular evidence to back this up, but would be happy enough to do it myself. Or does anyone have contradictory evidence?

Gavin A · Aug 28, 2014

yingli mono 250s are still about aren't they?

Obbit · Aug 30, 2014

Yingli mono are still about, but now have a black frame. Nearly all (at least from our 3 wholesalers) mono's are going black frame/all black. So this is the the only one I could find that has similar characteristics.

BruceB, this is as I understood it, that the string will balance itself, and the closer the parameters the less loses there will be.

I think I'll use it, as many of these differences are with in model tolerances.

Thanks for the help.