Energy Return on Investment
October 31, 2012
Energy return on investment (EROI) is the ratio of energy returned from an energy-gathering activity compared to the energy invested in that process. While EROI by itself is not enough to judge the virtues or vices of particular fuels or energy sources, it is a crucial component for such assessments because it indicates whether a fuel is a net energy gainer or loser (and to what extent). EROI studies for most energy resources show a decline, indicating that depletion has been more important than technological improvements over time.
From Energy: Overdevelopment and the Delusion of Endless Growth
Edited by Tom Butler, Daniel Lerch and George Wuerthner