Jump to content

Why GHI and Energy Yield is different for MET file with and without time-shift corrected .MET file?


Recommended Posts


I am conducting research on PVsyst performance on different Meteo datasets. I selected a very simple Solar PV array with zero degree tilt.

I downloaded the meteorological data from NSRDB for year Houston 2020 with 30 min temporal resolution. 

I uploaded the data through the PVsyst custom file method. It suggested me a -14 min shift. So I performed two simulations: i) Simulation with Time shift ii) Simulation without timeshift.

I am not able to understand why does PVsyst model produce difference in Annual GHI, Energy Yield and PR?



Without Timeshift

With Time Shift (-14min)

Annual GHI

1800 kWh/m2

1702 kWh/m2




Annual Energy

17381 kWh

16Test_Houston_Project.VC0- WITHOUT Timeshift.pdfTest_Houston_Project.VC1-WITH Timeshift.pdf290 kWh

Simulation Variant





The most surprising result for me is the annual GHI, since PV array was at the zero degree tilt, the amount of annual GHI shall not be different in the timeshifted case. 


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...