Hourly radiation

Hi,

I have a new problem with the climate weather files. I used to copy to my project weather files in CSV excel with 8760 (hourly) radiation datas, but now I have a csv excel of 52562 (10 min) radiation datas.

I tried to copy it to my project but it doesn´t work. How could I do to make it work without having to change all the weather file of 52560 datas?? if there is no other option, how couuld I pass all the 52562 datas from every 10 min of a year to the standard 8670 hourly data.

Thanks a lot!! Best regards

Hello,

For now, SAM's performance models require hourly weather data (8760 rows). The assumptions in the model algorithms are for hourly time steps. We are considering adapting the algorithms to work with smaller time steps, but do not have plans to include the capability in this year's versions.

The exception is the physical trough model, which supports sub-hourly time steps in a special SMW weather file format. However, the SMW file format requires that you have all of the weather data elements in the same time step resolution, not just the solar radiation data. So, in addition to your 10-minute global horizontal, diffuse horizontal, and direct normal radiation data, you would also need 10-minute dry-bulb, wet-bulb, and dew-point temperature data, and relative humidity, wind speed and direction, atmospheric pressure, and optionally albedo and snow depth data in the same resolution.

To use your 10-minute radiation data in SAM, you will need to find a set of data for the other elements (temperature, etc.) that matches the radiation data, and then convert the 10-minute radiation data to 60-minute data.

Best regards,
Paul.

Is there any way to use the scripting language to be able to use minute radiation data?

Hi Paul,

I actually have all that datas required by SAM in a 10-minute version, dry-bulb, wet-bulb, and dew-point temperature data, and relative humidity, wind speed and direction, atmospheric pressure.I have exactly the same parameters that the files I previously copied to my project but in 10-minute version. So I would appreciate if you could tell me how to convert it into a hourly version.


Thanks a lot

Best regards.

You could either write a program or script to do the conversion, or try to use a spreadsheet program like Excel. I hesitate to give you advice about how to do the conversion -- I think you'd want to do something like summing the radiation values and averaging the other weather parameters. Perhaps someone with more experience processing weather data can give you more specific advice. The user manuals for the TMY3 ( PDF 1.7 MB and TMY2 datasets may be a helpful resource for deciding how to do the conversion.

Best regards,
Paul.

You could use SAM's scripting language (SamUL) to read the original data from a file, perform the calculations to convert the data to hourly data, and write the data to another file. The CustomizeTMY3 function may be useful for that -- it basically automates the process of cutting and pasting hourly data into an existing TMY3 file that you do by hand in the TMY3 Creator window. (You'd have to write the latitude, longitude, time zone, and elevation data to the file's header using a different function.)

You could also use a different scripting or programming language to do the conversion -- I'm not sure there's an advantage to using SamUL unless you plan to do the conversions and run simulations in the same script.

Best regards,
Paul.