Parasitics - Solar tower (molten salt) with thermal storage

For a solar tower (molten salt) model with thermal storage, I would like to know whether by dividing:
"Receiver thermal power to HTF less piping loss (MWt)" by "Field incident thermal power (MWt)" in an instantaneous basis,
1) would I obtain both the efficiencies of the solar field and the receiver, which I guess so
2) would it account also for the parasitics from the solar field to the power output from the receiver?

If 1) is yes, would it be the same than multiplying "Field optical efficiency" by "Receiver thermal efficiency"?

Last:
3) Which is hence the most meaningful way to account for parasitics in an instantaneous basis when calculating the efficiency of the solar field and receiver?
4) Which is the most meaningful way to account for parasitics in an instantaneous basis when calculating the efficiency of the solar field, the receiver and the power cycle?

Thanks,

Tom

Hello Paul Gilman, would you please have any idea one these questions?

Thanks.

Dear Tom,

SAM accounts for the parasitic losses by subtracting the MWe value from the "gross" electric output of the power cycle. Those variables have names that begin with "Parasitic" in the list of output variables. For example, the parasitic power required for receiver and HTF pumping is accounted for by the "Parasitic power receiver/tower HTF pump" and is not accounted for in your equation.

The "Rec. thermal efficiency" value in in the results does not include piping losses, but "Rec. thermal power to HTF less piping loss (MWt)" does. You should get similar results from the following equations:

A = ( Rec Thermal Power to HTF Less Piping Loss MWt + Rec Header/Tower Piping Losses MWt ) / Field Incident Thermal Power MWt

B = Field Optical Efficiency * Rec Thermal Efficiency

The small difference between A and B is due to numerical convergence tolerances in the model.

Best regards,
Paul.