Could not find output fields (SamUL, Molten Salt Tower)

solarjoe
Topic Author
Senior Member

03 Dec 2012 14:33 #1046 by solarjoe

Could not find output fields (SamUL, Molten Salt Tower) was created by solarjoe

Hello,

I tried to run some parametric calculations an a
Molten Salt Tower using SamUL but I was not able
to find some of the output variables.

Can someone of tell me the names or where to find them?

On page "Heliostat Field" I could not find
- Total reflective area
- Number of heliostats
(I guess these are set by the Optimization Wizard after running it...)

On page "Tower System Costs" am missing
Total Installed Cost
Heliostat Field Investment cost (2nd from above, right side),
I could calculate this myself but I could not find the
variables mentioned before...

I hope you can help me.

Kind regards,
Joe

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Paul Gilman
Platinum Member

03 Dec 2012 22:26 #1047 by Paul Gilman

Replied by Paul Gilman on topic Could not find output fields (SamUL, Molten Salt Tower)

Dear Joe,

All of the variables you list are what we call "calculated values" that SAM displays on the input pages for your reference. SAM calculates their values using the values of input variables. They should appear in blue and not be editable values. Because those are not input values that you can edit directly, they are not available as parametric variables.

To do a parametric study on one of those values, you would need to use one of the variables used to calculate the value. For example, to do a parametric study on Total Installed Cost (not available as a parametric variable), you could use the Heliostat Field cost, which is available as a parametric variable.

Best regards,
Paul.

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solarjoe
Topic Author
Senior Member

04 Dec 2012 08:07 #1048 by solarjoe

Replied by solarjoe on topic Could not find output fields (SamUL, Molten Salt Tower)

Hello Paul,

thanks for you quick response.

Ok, I get that so far. But it is possible to read all variables
that are used to calculate the "calculated values" ?

Since I would like to get the total heliostat field costs
(costs/m^2 field * installed mirror area m^2) I need the installed
mirror area as the costs/m^2 are an input variable.

But I can not find something like that using "Browse Output Variables"
in the SamUL Editor. If I type "helio..." in the textbox the only variable
available is "heliostat drive electical consumption".

Kind regards,
Joe

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Paul Gilman
Platinum Member

04 Dec 2012 21:22 #1049 by Paul Gilman

Replied by Paul Gilman on topic Could not find output fields (SamUL, Molten Salt Tower)

Hi Joe,

Those variables are inputs, so you should use the SamUL input browser to find them, not the output browser. For example, the heliostat cost in $/m^2 is listed in the browser under "Tower Capital Costs" as "Heliostat Field Cost per m2 ($/m2) (DOUBLE)." Its variable name is csp.pt.cost.heliostats_per_m2.

Best regards,
Paul.

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solarjoe
Topic Author
Senior Member

05 Dec 2012 07:28 #1050 by solarjoe

Replied by solarjoe on topic Could not find output fields (SamUL, Molten Salt Tower)

Hello Paul,

as I wrote before, the problem is not the variable
"Heliostat Field Cost per m2 ($/m2) (DOUBLE)".
I found that one quickly in amongst the input variables.

I need the "calculated variable"
"Total reflective area" or "Number of Heliostats"
to calculate the total heliostat field costs.

One way I found is to sum the values in the azimutal/radial zones table
to get the number of heliostats.

Is this how the field is calculated or is there a more elegant way?

Kind regards,
Joe

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solarjoe
Topic Author
Senior Member

05 Dec 2012 07:52 #1051 by solarjoe

Replied by solarjoe on topic Could not find output fields (SamUL, Molten Salt Tower)

Ok, I found a workaround to get the number of heliostats:

GetInput("csp.pt.sf.user_field")

returns an array, with the numbers of helistats in the
radial/azimutal zones.

But you have to look out:
The first two numbers in that array are
"Number of radial zones" and "Number of azimutal zones",
the last number in this array is "Span Angle".

It is a bit cryptic, but it seems to work that way.

Still, is there an easier way?

Kind regards,
Joe

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