We must make our energy choices “carefully, intelligently and co-operatively”

EROEI is, or should be, the most important physical criterion used to assess the practicability of a proposed energy system for two reasons:

clipped from europe.theoildrum.com First, if the EROEI of an energy system is 1:1 or lower, it is no longer an energy source. As the EROEI drops below 1:1, it becomes an energy sink. This is important now, because society currently benefits from such high EROEI from fossil fuels that the low EROEI of alternatives may not be as obvious as it would otherwise be. The growth in use of corn-based ethanol as a substitute for fossil fuel in the US vehicle fleet is an example where it is uncertain that the biofuel-based energy system delivers any net energy (Cleveland et al, 2006)20. Second, the energy choices made now, if they are not made with a grasp of the wider implications of a reduction in our energy systems’ overall EROEI, will cause a profound, painful and largely unexpected and apparently inexplicable reduction in the complexity of society: in other words, an unmanaged and protracted collapse.