Hello,
I tried using the physical trough model with default inputs (optimized for the solar resource of Tuscon, Arizona), and see that there are long periods in the winter months where there is not sufficient solar energy to meet the power cycle's thermal energy requirement. During those times the system consumes energy from the grid (negative net energy) to prevent the fluids in the solar field and storage tanks from freezing. You can see that by plotting the following variables in the Time Series graph on the results page:
Net electric power output (kWh)
Freeze protection energy (MWh)
Tank freeze protection energy (MWh)
This suggests that given the data in your weather file, the solar resource is not sufficient for a 100 MWe power cycle with 6 hours of storage and a solar multiple of 2. Please see the instructions under "Sizing the Solar Field" in the
Solar Field topic
of SAM's Help systems for a suggestion of how to design the system for a given solar resource.
Best regards,
Paul.