Directly Assigning Weather File Elements in PySAM without using a weather file

matan
Topic Author

17 Jun 2020 13:36 #8318 by matan

Directly Assigning Weather File Elements in PySAM without using a weather file was created by matan

Hello!

I am wondering weather is possible to directly run the PVwatts model without using a weather file, and directly assigning the sequences of weather data to the SolarResource.solar_resource_data attribute. I tried the following, but I always get Annual Energy = 0, and all elements of ac out = 0. What am I doing wrong? Or is what I am trying to do not possible.

Code:

import PySAM.Pvwattsv7 as pv

model = pv.default('PVWattsNone')

wspd = [0, 0, 0.83... # 8760 elements of data. ie len(wspd = 8760)
tdry = [10.3, 10.54...
dn = [0, 0...
dh = [0, 0...
year = [2019, 2019 ...
month = [6, 6 ...
day = [1, 1 ...
hour = [0, 0, ...
minute = [0, 15 ...

model.SolarResource.assign({'solar_resource_data':{'dn':dn,
                                                   'df':dh,
                                                   'tdry':tdry,
                                                   'wspd':wspd,
                                                   'lat':51.4,
                                                   'lon':1.1,
                                                   'tz':0,
                                                   'Elevation':16,
                                                   'Year':year,
                                                   'Month':month,
                                                   'Day':day,
                                                   'Hour':hour,
                                                   'Minute':minute,
                                                   'albedo':0.5}})
   
model.execute(1)
model.ac_annual #0.0 kWh

thank you,

Matan

Code:

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pgilman

17 Jun 2020 17:05 #8320 by pgilman

Replied by pgilman on topic Directly Assigning Weather File Elements in PySAM without using a weather file

Hi Matan,

You're on the right track.

The code beginning at this line in common.cpp of the SSC source code should help you see how to format the table correctly.

Best regards,
Paul.

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matan
Topic Author

17 Jun 2020 17:08 #8321 by matan

Replied by matan on topic Directly Assigning Weather File Elements in PySAM without using a weather file

Hello Paul,

Thank you for your response. I figured out my problem. I used 'Elevation' as a key instead of 'elev'. It works now.

Best,

Matan

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matan
Topic Author

02 Jul 2020 17:44 - 06 Jul 2020 09:52 #8388 by matan

Replied by matan on topic Directly Assigning Weather File Elements in PySAM without using a weather file

Hello ,

I have another followup question to this! Reading through the documentation for PVwattsV7: nrel-pysam.readthedocs.io/en/2.0.2/modules/Pvwattsv7.html , I am not sure where I would input "snow"-depth.

I am using the direct assignment method to assign weather data, rather than reading from a weather file. Looking at the SolarResource.solar_resource_data, I see that "snow" (nor "albedo") is included in the 'info' . Can I assign snow and albedo as part of a the "solar_resource_data" dictionary?

Best,

Matan

Attachments:

...ource-data.png

Last edit: 06 Jul 2020 09:52 by pgilman.

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pgilman

06 Jul 2020 09:56 #8402 by pgilman

Replied by pgilman on topic Directly Assigning Weather File Elements in PySAM without using a weather file

Hi Matan,

You can use the documentation of solar_resource_data for pvsamv1 as a reference: nrel-pysam.readthedocs.io/en/2.0.2/modules/Pvsamv1.html .

Best regards,
Paul.

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