Aggregate Efficiency Index

Measuring improvement in corporate-wide energy performance can be challenging especially when manufacturers produce more than one product across a diverse portfolio of operations.  For manufacturers that struggle with understanding how the overall energy performance for the corporation has changed, US EPA’s ENERGY STAR program provides guidance for measuring that change. “Aggregate Efficiency Index,” An ENERGY STAR Guide for Evaluating Performance in Diverse Organizations explains how companies with diverse operations or products can accurately calculate, evaluate, and report changes in aggregate energy intensity.


Aggregate Efficiency Index Cover

Using an Aggregate Efficiency Index (AEI) is well suited for companies that have:

  • A range of production activities and products
  • Different sizes and types of facilities
  • Varying energy use levels across facilities
  • Recently opened or acquired facilities
  • Recently closed or sold facilities
  • Multiple business units
  • Different production or growth rates across a portfolio of facilities
  • Require a corporate-wide metric to communicate energy performance to executives, external audiences, and other stakeholders

The AEI approach is based on a similar method used by the U.S. Bureau of Labor Statistics to calculate inflation and has been used by leading ENERGY STAR industrial partners. The guide features a case study of how Corning Incorporated made use of the AEI to evaluate corporate performance that involved business unit from around the world.