Suggest to link your capital cost calculation with solar field area not kWh

Hi, Paul
I used to two different design parameters to come up with the same solar field area required.
Case 1: DNI = 700 W/m2, SM = 2.2, TES = 10h
Case 2: DNI = 400 W/m2, SM = 1.2, TES = 10h
Both come up a required land area  =212 acres
However the LCOHs from two design are significantly different. The root cause is due to your financial model which linked the capital cost to thermal MWh at field, not the field size. With a given thermal sink capacity (67MW), the receiver thermal power is 147 MW for Case 1, and that for Case 2 is 80.4 MW only. This creates a big difference in LCOH calculation. 
I believe the capital cost of two design should be very close to each other given the fact of the same size of solar field required. 
Could you please comment on my remarks above and see if there is any updates in SAM to fix this?

Best regards,
Harry

Hi Harry,

From your mention of LCOH, I assume you are asking about one of the industrial process heat (IPH) models, either the Parabolic Trough - Heat model or the Linear Fresnel Direct Steam - Heat model.

Unlike the concentrating solar power (CSP) models for electric power generation, the IPH models use a simple fixed charge rate (FCR) method to calculate the levelized cost of heat (LCOH). The CSP models use a detailed cash flow model to calculate a range of financial metrics including net present value, levelized cost of electricity, internal rate of return, etc. The CSP models have more detailed cost inputs, so you can specify costs in $/m2 of solar field area.

For the IPH models, I wrote an LK script that you can use to calculate the LCOH using capital and operating costs given in $/m2. It uses the same method as SAM, but adds a couple of cost category inputs. See the fcr-lcoh-with-cost-per-area.lk script on the LK Samples page (download instructions are  at the bottom):

github.com/NREL/SAM/tree/develop/samples/LK%20Scripts%20for%20SAM

Best regards,
Paul.