Size of field - Parabolic Trough System

Starting with the default values of a 100m long parabolic trough with an aperture of 5m, we follow the calculations on SAM for the Scott 2008 evacuated tube collector. However, we require a power output of 500 MWe instead of the default value of 111 MWe. The exact area of the field changed to accomodate the increased power demand, but the default value inputs for the trough size remained the same. Why did it not change to accomodate the requested increase in power output? Can you design with SAM a trough system starting with the size specifications of the parabolic trough and solar insolation to determine what the power output would be?

To change the field aperture area, SAM changes the number of collector loops in the field, not the collector dimensions.

The trough dimensions and other specifications are on the Collectors (SCA) page.

When you choose Option 1 on the Solar Field page, you specify a solar multiple, SAM calculates the field aperture area equivalent to the solar multiple and then calculates number of loops required for that field aperture area. You specify the number of collectors per loop at the bottom of the Solar Field page.

For Option 2, you specify the field aperture area, and SAM calculates the number of loops.

Sizing the trough system in SAM involves determining the optimal field aperture area to maximize the system's annual electric output (or income from electricity sales) while minimizing costs for a given power block nameplate capacity. For systems with storage, the sizing problem involves determining the optimal combination of field area and storage capacity. That process is described in SAM's Help system, in the Solar Field topic under "Sizing the Solar Field."

The "Irradiation at Design" input variable on the Solar Field page is the design insolation value that SAM uses for the sizing calculations.

Best regards,
Paul.