[RE-wrenches] Voltage degradation

[Drake Chamberlin]

Esteemed Wrenches,

How much voltage overhead should we have available on our arrays to 
allow for inverters not to fall out of their DC voltage operating 
range?  Since the module power degradation is 20% over the warranty 
period, I usually shoot for a module voltage that can drop 20% and 
still be within the MPPT range of the inverter under the average high 
temperatures, since most of the degradation is in voltage.

Am I being too conservative with this number?  It always pushes the 
number of modules to the top of what is allowable on the string for 
the extreme low.

Thanks,


Drake Chamberlin
Athens Electric
OH License 44810
CO License 3773
NABCEP TM  Certified PV Installer
Office - 740-448-7328
Mobile - 740-856-9648  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20100406/a2be94b1/attachment-0003.html>