Power Tower Optimisation

To optimize the solar multiple and storage capacity for the power tower models, you have to run the optimization wizard for each combination of solar multiple and storage capacity values. (The wizard determines the optimal number and position of heliostats, and the optimal tower height.) Because you have to specify values in the Optimization Wizard window and click the Optimize button, it is not possible to generate the data for the graphs using the Parametric analysis option. The Power Tower Optimization sample file includes a SamUL script that automates the process, and creates a table of data that you can graph with spreadsheet software. The script sets the value of the solar multiple and storage capacity variables, runs the optimization wizard and then runs a simulation for each combination of values, and writes a table of LCOE values for each set of results to a text file.

The parabolic trough models do not require the extra step of running the optimization wizard, so you can create the table or graph of LCOE vs solar multiple and storage capacity using results from the parametric analysis. For the trough models, SAM simply scales up or down the solar field. Unlike the power tower models, it does not need to determine a new layout for different solar multiples.

Best regards,
Paul.

To use the SamUL script in the sample file Power Tower Field Optimization.zsam in your own file:

1. Open the sample file.

2. On the Param Storage Script tab, click the Export Script to a File button, and save the .sul file to a folder on your computer. The .sul file is a text file that contains the SamUL script. (Do not use the Save As command on the File menu because that saves the .zsam file, not the script.)

3. Close the sample file, and open your .zsam file.

4. On the Developer menu, click New SamUL Script to create a new scripting tab.

5. On the Script 1 tab, click the Load a Script from a File button, and open the .sul file.

You will need to modify the script to work with your file by changing the case name in the SetActiveCase() function.

The reference DNI is a nominal value that SAM uses to size the solar field. Making it an input variables (as it is in the physical trough model) tends to cause more confusion than be helpful.

Best regards,
Paul.

No. SAM displays case names in tabs along the top of the Main window. The SAM file (.zsam) may contain more than one case.

Best regards,
Paul.