meteofile Timeshift of NREL data

[Peter.W]

Hello, 

I was trying to create a .Met and .SIT file for an NREL meteo file. I used the "NREL NSRDB Hourly TMY" Data source and received an error for a 360 minute timeshift. I don't completely understand the functionality of timeshift, but after looking into there didn't seem to be a way to fix the error while still using the "NREL NSRDB Hourly TMY" source. My attempted solution was to take the NREL data and convert it to a PVsyst Standard format with the command #timeshift 360 in the 1st and second column. It appears to have updated the timeshift although I do get two errors now. I get a comment that "This file is not a valid PVsyst Standard Meteo file the line definining the unit is empty or missing". It still lets me go past this where i further receive the error invalid meteo file time shifted by 0 minutes. How can I go about fixing this?

[Michele Oliosi]

There seems to be a "time zone" setting in the NREL TMY header, for example:

723740,"WINSLOW MUNICIPAL AP",AZ,-7.0,35.033,-110.717,1490

Did you try changing its value ? It may be zero currently and needs to be changed to -6.0, or the opposite way. Let us know if this works

[Peter.W]

I updated the local time to 0 (it was previously -6) and am still getting a 360 minute time shift error.

 

 

 

[Michele Oliosi]

Hi, I see, thanks for checking this.
We would need to see the file to find out what is going on. Can you send us the source file over at support@pvsyst.com ? We will have a look asap.

[Michele Oliosi]

Hello,

Although this page (https://www.pvsyst.com/help/meteo_import_nrel_nsrdb_viewer.htm) needs an update because the interface has changed, the basic steps are still correct, i.e., you should use the option “Convert UTC to local time”.

Your file is in UT, so it cannot be imported with the PVsyst “Known format” mode. You have three choices :

• redownload the data with “Convert UTC to local time”,
• use the “Custom file” option instead,
• or convert the file to the PVsyst standard file format. As stated in the help, https://www.pvsyst.com/help/meteo_pvsyst_standard_format.htm you should use the tag: “#Time reference, UT” to specify that the data is in UTC.

 

[Henry B]

On 12/14/2023 at 5:31 AM, Michele Oliosi said:

Hello,

Although this page (https://www.pvsyst.com/help/meteo_import_nrel_nsrdb_viewer.htm) needs an update because the interface has changed, the basic steps are still correct, i.e., you should use the option “Convert UTC to local time”.

Your file is in UT, so it cannot be imported with the PVsyst “Known format” mode. You have three choices :

• redownload the data with “Convert UTC to local time”,
• use the “Custom file” option instead,
• or convert the file to the PVsyst standard file format. As stated in the help, https://www.pvsyst.com/help/meteo_pvsyst_standard_format.htm you should use the tag: “#Time reference, UT” to specify that the data is in UTC.

 

Worked for me, i downloaded from NREL and didnt have it in local time, it was in UTC