Parabolic Trough - Physical - Effect of aperture area on thermal power to HTF

Hello PySAM Community,I've been conducting a series of simulations using PySAM version 5.1.0, leveraging the JSON configuration exported from the latest version of SAM. My simulations focus on varying the total aperture area (using the parameter) within a range from 100,000 m² to 2,000,000 m². The simulations utilize steam as the heat transfer fluid (HTF) with operational temperatures set between 25°C and 100°C.To evaluate my simulation results, I calculated the estimated received thermal power to HTF ( ) per unit of aperture area, expecting this normalized value (in kW/m²) to remain consistent across different aperture sizes. However, I observed that the value decreases as the aperture area increases, which was unexpected. For instance, with an average HTF operating temperature of 100°C, I recorded the following results:

• For an area of 100,000 m²: Thermal Power to HTF = 647 kWh/m²
• For an area of 1,000,000 m²: Thermal Power to HTF = 619 kWh/m²
• For an area of 2,000,000 m²: Thermal Power to HTF = 606 kWh/m²

Could someone please help me understand why increasing the aperture area affects the normalized thermal power to HTF in this way? Are there specific factors or system dynamics within PySAM's CSP model that I should consider which could explain this trend?Thank you for your guidance and insights!

Hi Paulo,

The best way to explore this question is to change the value of that input in SAM and see how the results change there. It is likely that there are interdependent input variables that the SAM user interface manages that you will have to manage manually in PySAM.

I'm also no sure what specific variable "Thermal power to HTF" represents, but those results suggest as the aperture area increases, losses increase, which decrease the energy available to the HTF.

Best regards,
Paul.