See also: Has Regional Imports, In-Area Import Fraction, In-Area Export Fraction
This variable specifies the percentage fraction of requirements for an Output fuel of a module that is imported from each other region within the Area. It is only visible when editing multi regional data sets and when the Has Regional Imports variable is set to Yes . In addition, this variable is only visible when you enable Allow Trade Among Regions: an option on the Calculation tab of the Settings screen.
Regional Import Fractions are specified as the percentage of requirements for each output fuel in a region met by imports from each other region in the area. Each value must be in the range 0-100% and values must sum to less than or equal to 100% across all regions.
There are two basic methods of specifying trade among the regions in a LEAP area.
Method 1 uses the Regional Import Fraction variable (described above) to directly specify imports among specific regions for each output fuel of each module.
Method 2 allows you to specify values for the In-Area Import Fraction and In-Area Export Fraction variables under the Resources branches. This approach first calculates overall import requirements for each fuel in each given area. Next, it species what fraction of those imports are met within the area (as opposed to beyond the area) using the In-Area Import Fraction variable. Finally it uses the In-Area Export Fraction variable to specify which of the regions meet those in-area requirements.