Welcome to WEAP's Website WEAP
WEAP is an initiative of the Stockholm Environment Institute.


About WEAP

Home
Why WEAP?
Features
What's New?
Sample Screens
Demonstration
Publications
History and Credits

Using WEAP
Download
Licensing
User Guide
Tutorial
Videos (YouTube)

User Forum
Discussions
Members List
Edit Profile

Additional Support
Training
University Courses
Collaboration

About Us
SEI-US Water Resources Program
Please Contact Us

LEAP
Interested in Energy?
Read about LEAP: SEI's software for energy planning.

Link WEAP and LEAP for combined Water-Energy planning.
Watch a video demo!
   

User Forum

All Topics | Topic "Importance of order of addition of transmission links"
Log in to post new messages or reply to existing messages.
 
Author Message
Mr. Adil Mounir

Subject: Importance of order of addition of transmission links   
Posted: 7/28/2020 Viewed: 6393 times
I made an experiment where I would add transmission links from 4 rivers to 1 demand node. Each time, I would obtain different results despite having the same parameters. I have made a video to better illustrate my confusion. Here is the link to the video:

https://www.youtube.com/watch?v=j2lBWmPpBFg&t=92s
Mr. Jack Sieber

Subject: Re: Importance of order of addition of transmission links   
Posted: 7/28/2020 Viewed: 6390 times
Dear Adil,

WEAP does not try balance or make equal the amounts supplied from sources with the same supply preference (e.g., River 1 and River 2), as long as all other constraints are satisfied. Therefore, I am not surprised that the allocations from those two sources can vary based on their creation order – this would affect the order in the equation matrix created for the linear program solver used by WEAP, and because it has many degrees of freedom in solving the allocation equations, the results can be arbitrary. (That’s just in the nature of LP solvers when there is not just one unique corner solution.) However, I am surprised that the allocations from River 3 and River 4 vary. Because the preference for River 3 is higher than River 4, WEAP should allocate as much water as possible from River 3, and only then allocate from River 4.

By the way, which solver did you use, lpsolve or XA?

Can you please send me your WEAP area so that I can test it? The easiest way to do this is from WEAP. On the main menu, go to Help, Send Email to WEAP Support. Make sure to select "Attach area" so that WEAP will attach your area to the email to me.

Best regards,
Jack

Topic "Importance of order of addition of transmission links"