NEMO

See also:  Introduction to Optimization

Syntax

NEMO(Solver)

Description

When editing the Optimize and Energy System Optimization variables, you can simply enter the value Yes to enable partial or full energy system optimization respectively.  Entering a Yes value instructs LEAP and NEMO to run using whatever is the fastest solver installed on your PC. For example, if GUROBI, CPLEX, or XPress are installed on your PC, LEAP will use those in this situation in preference to the built-in solvers (Cbc, HIGHS and GLPK).  

We recommend simply entering a Yes in most circumstances as your model can then be shared with and run by another user, even if they do not have that particular solver installed on their PC.

For finer grade control, you can make use of the NEMO function to specify a particular solver.  You can even use different solvers when calculating different scenarios.  This can be useful for checking that different solvers are yielding the same results.  In some rare cases, different solvers may yield slightly different results (most often due to optimizations of the solver code designed to speed up calculations).  The allowable keywords used for the Optimize and Energy System Optimization variables are currently as follows:

  • Yes: Optimize using NEMO and the fastest available solver installed on your PC.
  • No: Use LEAP's accounting and simulation calculation methods.
  • NEMO(GLPK): Optimize using NEMO and GLPK.
  • NEMO(CBC): Optimize using NEMO and Cbc.
  • NEMO(CPLEX): Optimize using NEMO and CPLEX.
  • NEMO(GUROBI): Optimize using NEMO and GUROBI.
  • NEMO(HIGHS): Optimize using NEMO and HiGHS.
  • NEMO(MOSEK): Optimize using NEMO and MOSEK.
  • NEMO(XPress): Optimize using NEMO and XPress.

Note that the commercial solvers CPLEX, GUROBI and XPress must be purchased and installed separately from LEAP and NEMO. MOSEK is installed with NEMO but you must have a properly purchased and installed license file for it in order for it to calculate. Use the orange  Exp button () in the data entry table to quickly choose a solver from among those installed on your PC.