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System Advisor Model (SAM)

LCOE inconsistency, Cash Flow

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Ismael
Topic Author

11 Jan 2019 15:22 #6598 by Ismael

LCOE inconsistency, Cash Flow was created by Ismael

Hi, I'm simulating a 100 MW central receiver CSP plant (without TES). In the "Summary" of results, SAM tells me that the resulting nominal LCOE is 26.02 cents / kwh, which coincides with the information shown in the "Cash Flow" tab. However, if I check the detail of the cash flow with the "Send to Excel with Equations" tool, it turns out that the nominal LCOE shown is 29.44 cents / kwh.
Reviewing, I can see that the problem is that in the Cash Flow tab and in the Excel sheet that delivers the program, NPV (Net Present Value) values are very different, generating that these sources deliver different LCOE values. Apparently what happens is that both sources take different values for the total cost of the project.

I enclose some images to expose the problem, in addition to the Excel spreadsheet, where I mark with red the cells I am looking.

I would appreciate any help you can give me to resolve this inconsistency.

Regards,
Ismael

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pgilman

23 Jan 2019 18:56 #6599 by pgilman

Replied by pgilman on topic LCOE inconsistency, Cash Flow

Dear Ismael,

The Excel workbook attempts to replicate the SAM C++ calculations in Excel formulas, and does not always generate exactly the same results as SAM.

Without seeing your SAM file, it is hard for me to tell what is causing the difference in results. You can see that the annual costs in the worksheet (Row 124) are different than the annual costs in the SAM cash flow, so you could trace through the formulas in Excel to find the source of the discrepancy.

Before doing that, you might want to regenerate the Excel workbook to make sure the inputs are consistent.

Best regards,
Paul.

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