Derate factor

Start
Prev
1
Next
End

coolmanhalo
Topic Author

28 Nov 2013 08:29 #1997 by coolmanhalo

Derate factor was created by coolmanhalo

The derate factor by default is 0.77

The website seems unclear if the number is for no tracking, single axis, or 2 axis.
Could you suggest the appropriate multipliers

thanks

Please Log in or Create an account to join the conversation.

Paul Gilman

02 Dec 2013 23:51 #1998 by Paul Gilman

Replied by Paul Gilman on topic Derate factor

Hello,

I assume you are asking about the default value of the DC to AC derate factor for SAM's PVWatts model.

PVWatts calculates the incident radiation for each hour of the year based on the array's orientation and the sun's position in each hour. The derate factor is independent of the tracking option.

Best regards,
Paul.

Please Log in or Create an account to join the conversation.

ENRES2018

30 Jan 2014 10:05 #1999 by ENRES2018

Replied by ENRES2018 on topic Derate factor

I want to oversize the solar PV array comparatively to Inverter power, how to configure the derate factor greater than 1?

Please Log in or Create an account to join the conversation.

Paul Gilman

03 Feb 2014 21:57 #2000 by Paul Gilman

Replied by Paul Gilman on topic Derate factor

The PVWatts model assumes that the inverter AC capacity is equal to the array DC capacity, so it is inherently oversized by the inverter's conversion efficiency.

The Flat Plate PV model may be a better option for this kind of analysis. That model has a DC-to-AC ratio input (on the Array page).

Best regards,
Paul.

Please Log in or Create an account to join the conversation.

Start
Prev
1
Next
End

Moderators: Paul Gilman