Stringing slightly different voltage amps panels?
- Thread starter Tallguy
- Start date
LakeHouse
Solar Enthusiast
Some more details would be helpful for us to give you a better answer, like specifications for the solar charge controller, and more the specifications for the panels (Voc, Isc, Imp, Vmp).
But generally speaking, there will be some small losses in efficiency because Imp will be slightly different between the panels and you’ll only ever get the lower of the two Isc values, but otherwise stringing those in series shouldn’t really be a problem for the panels.
If the combined, temperature corrected Voc is too high for your SCC, that’s a problem. Which is why we need more info…
zanydroid
Solar Wizard
Wasn’t that already answered?
Since the Impp don’t line up, there will be an efficiency loss due to that. Devices that are series connected all see the same current. Probably you can approximate the efficiency loss by taking the lowest Impp as the overall current of the string and computing from there using the I-V graphs of each panel. But this is not guaranteed to be the operating point.
Order won’t matter.
MisterSandals
Participation Medalist
Your voltages are 5% different so I suspect your secret amp numbers are too.
Your 1 panel will will have its amps dragged down to the amps of the other 2 similar panels.
Very minimal loss overall, less than 2%. (5% / 3)
TomC4306
Solar Obsessive
Yes.
No, doesn't matter.
400bird
Solar Wizard
In case it wasn't obvious from the answers you received, you didn't provide the needed information to get good answers.
The voltage of each panel isn't important to string performance/efficiency. It is important to your charge controller, but you said it was fine.
The current will be the same through the entire string, so the lowest current panel will drag down the other two. The voltage just adds up with each additional panel in series, so no effect on how the other panels are performing.
Asking what order to put them in series reinforces the theory that your learning. You should be open to answering questions so you can better understand how solar works.
The voltage of each panel isn't important to string performance/efficiency. It is important to your charge controller, but you said it was fine.
The current will be the same through the entire string, so the lowest current panel will drag down the other two. The voltage just adds up with each additional panel in series, so no effect on how the other panels are performing.
Asking what order to put them in series reinforces the theory that your learning. You should be open to answering questions so you can better understand how solar works.
