SAM's power tower models do not report the annual solar field efficiency, receiver thermal efficiency, or power cycle efficiencies. However, you can calculate the values by exporting hourly data to a spreadsheet, and calculating the annual values from the hourly data there.
Solar field efficiency = (Thermal energy on receiver) / (Total incident thermal energy) x 100%
Receiver thermal efficiency = (Receiver thermal power output) / (Thermal energy on receiver) x 100%
Annual gross cycle efficiency = (Gross electric power output) / (Receiver thermal power output) x 100%
Gross to net efficiency = (Net electric power output) / (Gross electric power output) x 100%
After running simulations, display the hourly variables on the Results page, and then export the data to a spreadsheet program:
See the attached Excel workbook for an example of how to make the calculations in a spreadsheet.
Best regards,
Paul.