I used the SAM tool's built-in downloader to get data for my location. It ended up coming from Station ID 891492, I guess. The data source appears to be NSRDB. I thought that this source included snow data, but when I go in the Shading and Layout page and check, "Estimate losses from snow coverage," I get the error message, "Weather file has no snow data. Simulation will fail."
Is there a way to overcome this for my location in the Chicago suburbs and include the snow losses?
Note that this data is very out of date, so is only suitable to see how the snow model works in SAM.
This data is also available in files in the SAM CSV format on the
SAM Weather Data
website page, listed with the NSRDB Archives in the table of free data sources.
Unzip the file and go to 1961 - 1990/ tmy2/ where you will find another zip file. Unzip tmy2_data.zip file and find the file for the location you want to model. You can find a list of stations in the TMY2 Users Manual available here: www.nrel.gov/docs/legosti/old/7668.pdf
Move the .tm2 file to your weather file folder, for example [user]/SAM Downloaded Weather Files. You can also rename it to something more recognizable than the station number, for example rename 26451.tm2 to anchorage.tm2
In SAM, on the Location and Resource page, choose the file from the Solar Resource library. If it does not appear in the library, try clicking Refresh Library, or Add/Remove Weather File Folders to add the folder containing the file so SAM can find it.
Look under "Weather Data Information" in the "Optional Data" section. If the file contains snow data, Minimum Snow Depth will be a number. If it does not contain snow data, it will be "NaN" for "not a number."
On the Shading and Layout page, under "Snow Losses" at the bottom of the page, click Estimate Losses from Snow Coverage.
I selected the weather data file for my area of interest, and I want to keep all the data that it has on that location. However, under maximum snow data it says NaN. The location is in AK so this is definitely incorrect. The field is blue and will not let me change it. Is there anyway that I can manually edit the maximum snow depth value?