Hourly Shading file for computation of production numbers(KWh)

Muhammad Farhan
Topic Author

18 Dec 2015 11:29 #3979 by Muhammad Farhan

Hourly Shading file for computation of production numbers(KWh) was created by Muhammad Farhan

I am using the SAM SDK for finding the production numbers using our own calculated Solar Access. Then problem that i am facing right now is that the production number are different on SAM tool and SAM SDK using the same weather file and same data. I would like to know that the way your are following for the computation of solar Access (both monthly and Annually) using the hourly based shade CSV. Because when i am putting my solar Access in your SDK then the results are pretty close when the solar access is greater then 90% and the difference between production numbers increases as solar access < 90% using the SAM SDK and SAM tool.

Is there any way to put our own hourly based shade CSV file in your SDK? as we do in SAM tool.
or any API for this!

Best Regards,
Farhan

Please Log in or Create an account to join the conversation.

Paul Gilman

18 Dec 2015 17:27 #3980 by Paul Gilman

Replied by Paul Gilman on topic Hourly Shading file for computation of production numbers(KWh)

Dear Farhan,
First, please make sure that you are using the same version of SSC in your API calls that SAM is using. To see the SSC version number for SAM, open the Help browser and click About.
It is possible that the inputs in SAM are not identical to the inputs in your code. You can press the Shift-F5 key in SAM to generate an LK script that lists all of the SSC input variables and their values.
You can use the

subarray1_shading

variable to read your own shading data. For example, if you have an 8760 column of beam shading losses stored in a variable called

shading_losses

for Subarray 2, you would assign it as follows (in LK script):

var( 'subarray2_shading:hourly' , shading_losses )

 
Similarly, you can assign month-by-hour shading factors to

subarray1_shading:mxh

, and azimuth-by-altitude losses to

subarray1shading:azal

. Note that the number suffix to

subarray

determines which subarray the shading losses apply to.
Best regards,

Paul.

Please Log in or Create an account to join the conversation.

Muhammad Farhan
Topic Author

21 Dec 2015 06:39 #3981 by Muhammad Farhan

Replied by Muhammad Farhan on topic Hourly Shading file for computation of production numbers(KWh)

thanks Paul for your reply.
I am working on php (ubuntu 64 bit) and i am using the pvwattsv5 module for my project.
I am adding a single line to my code and i have seen no impact on production number after adding or removing this line.

line: "sscphp_data_set_number($dat,"shading:hourly", [ 0, 0, 0, 0, 0, 100, 100, 100, 100, 75, 0, 0,...,75, 100, 100, 0, 0, 0, 0 ]);"

Best Regards,
Farhan

Please Log in or Create an account to join the conversation.

Paul Gilman

04 Jan 2016 18:11 #3982 by Paul Gilman

Replied by Paul Gilman on topic Hourly Shading file for computation of production numbers(KWh)

Dear Farhan,
Have you been able to change the values of other SSC variables in your PHP script? The

shading:hourly

variable is a one-dimensional array of 8760 percentage values, so if you correctly assign the values, you should see a difference in outputs like

gen

and

annual_energy

.
Best regards,
Paul.

Please Log in or Create an account to join the conversation.

Paul Gilman

04 Jan 2016 21:57 #3983 by Paul Gilman

Replied by Paul Gilman on topic Hourly Shading file for computation of production numbers(KWh)

Also, because the

shading:hourly

variable is an array, you should use the

sscphp_data_set_array()

function instead of the

sscphp_data_set_number()

function to assign it a value.
Best regards,

Paul.

Please Log in or Create an account to join the conversation.

Muhammad Farhan
Topic Author

07 Jan 2016 11:52 #3984 by Muhammad Farhan

Replied by Muhammad Farhan on topic Hourly Shading file for computation of production numbers(KWh)

Thank you paul for your reply,
I have already implemented this feature.
I have other questions as well.
Can you give me your email? so that i will discuss it with you.

Please Log in or Create an account to join the conversation.

Moderators: Paul Gilman

NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

NREL Home

NREL Research

Follow NREL

NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.