How to account for solar field cost in parametric modeling

Hi, Paul
I have been using Parametrics model and try to find the best design basis for DNI, Solar Multiple, and Thermal Storage time. The key economics in SAM is the LCOH in IPH modeling.
However, a lower LCOH target can always be achieved by Lower DNI and higher SM combinations, which imply larger solar filed area and cost! I could not figure out how the cost
of solar filed is accounted in SAM model and I can not find a output parameter to show the cost or area of the solar field changes. I believe there should be breaking point, where 
more solar filed added will result in a significant cost increase and should bring LCOH up after that point.
Could you please shed some lights on this issue?
Could you direct me to see if any SAM output parameters can indicate the changes of solar field (cost and area) as a results of input data (DNI, SM, TES) changes?
Thank you in advance!
Harry

Hi Harry,

SAM's industrial process heat (IPH) models use a simple fixed charge rate (FCR) method to calculate the "levelized cost of heat" (LCOH). That method represents the capital cost as one number in either $ or $/kW of system capacity. For IPH systems, the system capacity is the "target receiver thermal power" value shown on the System Design page.

Unlike the concentrating solar power (CSP) models, there is not a way to represent the cost of the solar field independently of the system capacity.

The solar field area is an input, so it is not reported in the results. You can use the solar multiple to vary the solar field area as a function of the heat sink power, and then adjust the capital cost to account for the solar field cost.

To do that with parametrics, you could use the Enter costs in $ option on the Financial Parameters page, and on the Parametrics page, create a table with solar multiple and fixed capital cost as the input variables, and manually enter values for the cost for each solar multiple value. You may have to do some testing on System Design and Solar Field input pages to compare the actual solar multiple and solar field area with the target solar multiple.

Best regards,
Paul.

Thank you, Paul