Hi Louw,
This issue should mostly be resolved in SAM 2020.11.29, just released this week.
For the Physical Trough model, there is a remaining issue that we should have time and resources to fix for the next version of SAM: In time steps when the solar field starts up, the time series results show more field thermal power leaving in HTF than goes to TES or the power cycle. This is because SAM models trough startup as a "recirculated" process where the warm outlet goes back to the cold inlet until the outlet reaches a threshold startup temperature.
For this recirculated model to work, it sets the inlet properties equal to the outlet properties at the end of the previous time step. This means that during a given time step, the outlet will slowly heat, but the model has to “dump” that energy because the inlet temperature is fixed. The model minimizes the influence of this by dividing the hourly time steps into 10 minute intervals so it can reset the inlet temperature before the outlet drifts too far away. (This contributes to making the physical trough model slower than it might be.)
A solution to this problem is for us to create a new variable to show this dumped energy so that field thermal power leaving in HTF is consistent with TES and cycle energy streams.
A better solution would be to connect the trough output to the cold tank during startup and actually keep that heat in the system, but that would require more time and effort to implement than we have available for now.
Best regards,
Paul.