“To troubleshoot, I set system capacity to zero to force no production or at least reach a positive result, but it hasn’t worked”
Would you give some details, what doesn’t work as expected? What other components drive the negative result? For example, if capacity is zero, then production variable is zero, but the fix cost or investment, drives the negative objective function? Or there are some constraints?
You may use AIMMS Mathematical Program Inspector under the diagnostic tool to check your model.
 

Hello,

First of all, thanks for your answer,

yes, i use the program inspector, honestly, my problem, is that i cant understand how the program inspector can help me!
I try to understand, by considering the demand of my clients, how much energy i buy from outside and how much energy the system produce!
little bit lost,
since, the capacity of different system in IES are variable and not parameter that i change them, 
when i put my energy exchange cost = 0(only the price, which the quantity that i can buy, the system will choose), obviously my profit is +, but has no sense, since it means that i have free energy!
Thanks for your support,

Hi, I’m afraid I could not get how your model works. If you would like to, you can share your AIMMS project with the running instruction, and I may look further.

Hi, I really appreciate your support, but since the model comes from my professor (it's my thesis), I suppose I can't share it. However, if possible, I can share some screenshots. Thanks a lot!

Hello,

still, Is there any possibility to share with you the model?
I really appreciate your support,
Any time, it's possible, i can share the model and structure,

thanks

If it is okay with you, you can share the project here. Screen shots with sufficient information is fine too, I guess..