enter POA data in weather file

Hi,

I have been trying to sort out how to enter POA data into a weather file. I have pyranometer measurements in the plane of array.
Following the Help embedded in SAM and some helpful discussions on the forum, unfortunately I still can't get it to work. Somehow my conversion skill does not satisfy SAM :)
I tried a couple of things: in "USA AK Adak Nas (TMY3) 1.csv" I only copied the TMY3 file from the SAM directory to my custom directory and changed nothing, this works fine. But with "USA AK Adak Nas poa 2.csv" the only thing I changed is the column header from DHI to POA.
Somehow SAM thinks the format of the file has changed, since it does not recognize it anymore. Adding my custom dir to the resource library it gives funny data in the file listing (see screenshot). The checker macro returns an error: "could not determine the number of records in CSV weather file". When I try to select the file from the list, SAM runs in an endless loop. Could you please tell me what's going on? I'm running SAM 2016.3.14


Hope you can help.

best regards,
Koen

Hello Paul,

thanks very much, now SAM accepts the file! I use excel on Mac, and saved it as Windows csv. Sorry I overlooked that post on the forum.

Unfortunately SAM does not use the POA data yet. If I replace the GHI, DNI and DHI columns with one column with heading POA, the simulation returns an error "invalid beam irradiance nan W/m2 at time [y:1998 m:1 d:1 h:0], exiting
Simulation pvsamv1 failed."
I have tried putting the GHI, DNI and DHI back in, setting to Nan, 0 and keeping the values. Only the last option runs OK, but then the POA data are not used.

The file checker macro tells me to have at least two irradiance components, but POA is the only one that's relevant in my case.
Can you tell me how to construct the csv such that SAM uses the POA data?

thanks,
Koen

Just wanted to let you know I solved my issue. thanks for helping.

Hi,
I (finally) succeeded in getting it to run. With the kind help of Paul and another forum member.
This is what I did and some additional tricks for people that are new to SAM or haven't got enough patience:

Whenever is referred to SAM help, you want to look in the help embedded in SAM. In the top right corner of the GUI, you'll find a tiny help button. It solves most of the problems. Do NOT search online it is not up to date.

most of the files listed in the solar source database, if not all, are in SAM csv format, contain three header lines:
Source,Location ID,City,State,Country,Latitude,Longitude,Time Zone,Elevation
TMY3,704540,Adak Nas,AK,USA,51.883,-176.65,-10,5
Year,Month,Day,Hour,GHI,DNI,DHI,Tdry,Tdew,RH,Pres,Wspd,Wdir,Albedo
and then the data

Usually these files contain GHI, DNI and DHI. To get POA in there, you either replace one of those columns or add a column headed with POA

Make sure you save the csv with the correct end of line character. Especially excel on Mac: save it as windows csv file. You'll need the CRLF (carriage return/line feed) or LF (line feed).

In the "Location and Resource" screen add the location of the csv file to the solar resource database (folder settings...) OR check the box below "Use a specific file on disk" and select your file with POA data

At the bottom of the "Location and Resource" screen expand the "Albedo - Sky Diffuse Model - Irradiance Data (Advanced) menu and check the box with POA data (either from reference PV cell, or Pyranometer)

This worked for me. I hope this post will help other people as well.

cheers,
Koen