First check to determine if Solver is already installed by clicking on 'Tools' on the main EXCEL toolbar and then on 'Add-Ins' on the dropdown menu, as indicated in figure 1 below.
The window shown in figure 2 will open and the box should be checked on the line Solver Add-In. If it is not, check the box, then click on the 'OK' button. Note that when GETEM was opened, the user was prompted regarding whether Enable or Disable Macros. If the user opted to Disable Macros, the file should be saved and then re-opened with the macro Enabled.
If the macro will not run after completing these steps, click on the 'Macro' option on the dropdown menu from the main tool bar 'Tools' icon (see figure 1). Click first on the macro "BinaryOptimum", and then on the Edit button. This will open the Visual Basic editor. Click on the main editor tool bar "Tools" icon and then References option shown in figure 3.
The window shown in figure 4 will open. Confirm the box next to SOLVER is checked, then click OK to close this window. Next close the Visual Basic editor, which should return the user to the GETEM spreadsheet. At this point the macro to optimize the binary cycle performance by minimizing the LCOE should run.