Jump to content

Possible error in the Performance Ratio´s help section


Recommended Posts

It seems to be a mistake in sign in the help section of the Performance Ratio https://www.pvsyst.com/help/performance_ratio.htm. In particular the help section shows a weather-corrected PR equation as: 

PR (corr)  =  E_Grid  /  ( PNomPV  * Σ hours   ( GlobInc / GRef  * (1 - muPmpp * (Tarray - TArrayAver) )

While the NREL paper (cited in the help section) https://www.nrel.gov/docs/fy13osti/57991.pdf shows the equation with a diferent sign mainly exchanging  (TArrayAver  - Tarray  ):

PR (corr)  =  E_Grid  /  ( PNomPV  * Σ hours   ( GlobInc / GRef  * (1 - muPmpp * (TArrayAver  - Tarray  ) )

Assuming muPmpp is a negative number. 

I will be happy to receive any feedback on this subject.


Link to comment
Share on other sites

Dear allanfisica,

You are right, there is a mistake in the help, we will update the values. Thank you very much for the feedback.

This also allowed us to find a different bug in the software that alters the value of the temperature corrected PR by a tiny amount (typically ~ 0.001). We will correct this in an upcoming patch.

Link to comment
Share on other sites

  • 2 weeks later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...