How much leeway on mixing panel types?

[Riverwind]

I want to mix 8 215 Kyocera with 3 Conergy 240's. If they are wired in series then the Imp is 8.09 for the Kyocera and 8.13 for the Conergy. Is this close enough to work? There will be three strings, two Kyocera 215's, 4 panels each and 1 Conergy 240's, 3 panels. Thank you!

[Halfcrazy]

My general rule of thumb is 5-10% difference. So if they are in series the ISC needs to be within 5-10% or if they are in parrellel the VOC needs to be within 5-10%

Ryan

[Vic]

Hi Riverwind,

Well,  it is not clear the exact part numbers of the Conergy PVs.  If they are the PH-240P series with 60 cells,   and the Kyo 215s are 54 cells,  then,  to me the answer is probably they will not work as a team.

Believe that all the Kyo 215s are 54 cell PVs (kinna an odd-ball).  So as I read your post,  there will be 216 cells in series on the Kyo strings of four,  and 180 cells in series,  if the guess on the Conergy PVs is correct.  Conergy did make some 72 cell PVs,  but believe that these were in a higher power range.

HOWEVER,  if you are running 72 cell Conergys,  the marriage appears to have been made in heaven.

Exact part numbers or exact specs on Vmp & Imp  do help reduce the guess-work,  and render more precise answers.

5% match of Imp for series strings,  or Vmp for parallel strings is very good.   10%  may be OK,  and as HC mentioned is about the uppper limit.

At these string Voltages,  your location,  vs the exact Classic CC you are choosing will make a difference.  In cold weather,  a Classic 150 may spend a number of mornings in Hyper VOC,  and perhaps even run the risk of damage if you are in a COLD climate.   It IS great that MidNite makes a line of CCs with varying Vin capabilities,  as you know.  Guessing done,  Vic