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Trough system power estimates

  • Jessica
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22 Apr 2021 13:39 #9489 by Jessica
Replied by Jessica on topic Trough system power estimates
Hi Paul,

And how is the "PC electrical power output: gross" calculated? it seems to be larger than the: "PC input energy" less the "startup energy".

Regards

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  • pgilman
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22 Apr 2021 17:39 #9490 by pgilman
Replied by pgilman on topic Trough system power estimates
Hi Jessica,

The power cycle gross output should be less than its input power. For example, from the default Physical Trough / Single Owner case:



If your file is showing otherwise, please attach a copy so that I can investigate.

Best regards,
Paul.
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  • Jessica
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22 Apr 2021 21:38 #9502 by Jessica
Replied by Jessica on topic Trough system power estimates
Hi Paul,

Thank you for the quick reply.

Are you comparing thermal to electrical energy? in my original claim what I have done is: I went to the tabular data, computed the following:

Manual gross electricity generation= ("PC input energy" - "startup energy" )x0.356

and compared it to the "PC electrical power output: gross" I am obtaining 8% larger value for the gross vs the manual computations which is leading me to believe that there's a certain boiler back-up of 8% being added to the PC input energy.

What do you think

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  • pgilman
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22 Apr 2021 22:05 #9505 by pgilman
Replied by pgilman on topic Trough system power estimates
Hi Jessica,

This screenshot shows the Data Tables tab on the Results page with variables that show that for hours except startup hours,

PC Gross Output (MWe) = PC Input (MWt) * PC Gross Efficiency



For startup hours, please see my final response in this thread: sam.nrel.gov/forum/forum-general/1987

Best regards,
Paul.
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  • Jessica
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23 Apr 2021 06:13 - 23 Apr 2021 23:12 #9509 by Jessica
Replied by Jessica on topic Trough system power estimates
Hi Paul,

Thanks a lot for the above, it helped with all the times except for the startup times.

First question is:

I am using the SAM 2020.11.29 version, startup is still an issue.

At startup, the efficiency is given to be really low. If I use however values of efficiency from the next timestep I seem to get closer values. I'll use your example to illustrate.
Last edit: 23 Apr 2021 23:12 by pgilman.

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  • pgilman
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23 Apr 2021 23:13 - 23 Apr 2021 23:14 #9511 by pgilman
Replied by pgilman on topic Trough system power estimates
Hi Jessica,

Sorry your message got cut off. Can you resubmit it?

Please attach each image as a file and then use the buttons to insert it in your message rather than pasting it into the editor.

Best regards,
Paul.
Last edit: 23 Apr 2021 23:14 by pgilman.

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