How can I get hourly data using "data_get_array" command in MATLAB?

Hello,

I was about to run several thousands of simulations on concentrated solar power (CSP) by using SSC in MATLAB. Although I was able to retrieve annual data from the Data Container with "data_get_number" command, I couldn't retrieve any hourly data with "data_get_array" command. Yes, I could get the hourly data from SAM, but I don't want to do that as I'm about to run a huge number of simulations and need to reprocess data with MATLAB. Is it because the names of the hourly variables in the Data Container are different from the ones in SAM?

I would really appreciate if anyone could provide a guide.

Thank you,
Ablimit

Dear Ablimit,

You should be able to get the hourly data. You can use the SDKtool to see a list of all input and output variables for the different compute modules. For most of the performance models in SAM, including the CSP models, the output variable is the hourly or subhourly electric power generated by the system.

For the module, the variables and are the net and gross cycle output, respectively.

Best regards,
Paul.

Paul in python, "gen" does in fact pull the KWh, but is there an accompanying array of dates and hours? If so, how do I pull that?

Hi Avery,

The gen array is single value of kW values with no timestamps.

If you are running one of the solar energy modules (pvsamv1, pvwattsv5, trough_physical, etc. and need to know the year, month, day, hour, and minute time stamp values used for the sun position calculations, you can get the time stamp value from the weather file.

Otherwise, SAM assumes that the first row of gen is the first time stamp on Monday, January 1. For an hourly simulation, that would be the hour ending at 1 am on January 1. It does not account for daylight savings time or leap years.

Best regards,
Paul.

Thank you so much for the response! This is an amazing tool
I could not find the documentation for "gen" anywhere. Is ther documentation about what you can call for  "data_get_array" or "data_get_number?"

Thanks again,

Avery.

Hi Avery,

The SSC input and output variables are not very well documented. Here are a few suggestions for learning about what the variables represent:

1. Use the SDKtool as described on the SDK webpage .
2. Use the variable documentation functions described in Section 3.4 of the SSC Guide (see link under Documentation on the SDK webpage .
3. Use the SAM desktop application to run simulations and explore the variables on the input pages and results page.

All of that said, the variable 'gen' is a time series array of the electrical output in kW of the power system you are modeling. Its value may be negative for some time steps. For example, a PV system's inverter may consume power at night, resulting in a negative value of gen for night-time time steps.

Best regards,
Paul.