Getting energy is getting less efficient
February 2nd, 2009A post by Euan Mearns at The Oil Drum: Europe contains this graph that illustrates what our energy crisis is all about.
The chart shows how the proportion of net energy available for society to use varies with EROEI. The shape of the curve shows that for EROEI > 10, the bulk of energy procured is available to society – to power industry, transportation, schools and hospitals. When EROEI falls < 10, there is an exponential increase in the amount of energy required to procure energy. Consequently, there is a corresponding decline in net energy available for society.
Mearns concedes that there is much uncertainty in the data and many large gaps in knowledge, and that the yellow arrow at EROEI = 9 is just a stab in the dark – we don’t know with any certainty what the minimum EROEI for modern industrial civilization is. But the overall picture is pretty clear. We’ve used up a significant portion of the easy-to-access fossil fuels and the average energy pool available to the global economy is therefore relentlessly marching towards lower aggregate EROEI.
Mearns warns that government policies aimed at propping up our old energy-squandering ways and subsidizing inefficient energy sources will lead to disaster.
Governments must accept that the way we use energy must change and that a painful period of adjustment lies ahead.