Hi!

The model aims to optimize the energy flow in my superstructure and minimize the cost. Most of the data in the listing file show that the status is superbasic and some of them are superbasic, at bound.

Here is the message showing on top of the listing file.

CONOPT 4.1 constructed the following irreducible infeasibility set (IIS).

The IIS consists of 1 constraint and 1 variable.

HWH(6) .. [ 9 | 273 | IIS ]

+ 1 * Techflow(HW,6) - 0.800 * NGflow(HWH,6) = 0 ; (lhs=-25630, scale=3600000) ****

name lower level upper scale

Techflow(HW,6) -inf -25630 inf 3600000

NGflow(HWH,6) 0 0 inf 3600000 <--- pivot column

The constraint is stated like this:

HWH(t):

Techflow('HW',t)=EfficiencyNG('HWH')*NGflow('HWH',t)

Attached is the zipped file for my model. I would appreciate if anyone could help me to solve this.

**Best answer by Marcel Hunting**