Over the falls with ERoEI

SUBHEAD: The cliff we are about to go over with Energy Returned on Energy Invested.

By Euan Mearns on 2 February 2009 in The Oil Drum -
http://europe.theoildrum.com/node/5051
  



Image above: Over the falls in a high tech cocoon. From http://blog.wwaraft.com/blog/dc-weekend-trips
"We will discuss the intersection between Energy and the Economy, and I will make the point that it was no accident that our exponential, debt-based money system grew up at precisely the same moment that a new source of high quality energy was discovered that proved capable of increasing exponentially right alongside it. Now we embark on the precise line of thinking that completely dominates my investing and purchasing habits. I call it energy economics. With sufficient surplus energy, humans can construct remarkably complex creations in short order. Social complexity relies on surplus energy. Societies that unwillingly lose complexity are notoriously unpleasant places to live. Given this, shouldn’t we pay close attention to how much surplus energy we’ve got and where it comes from?"
- By Chris Martenson from Crash Course Chapter 17b: Energy Budgeting
Energy Efficiency of Energy Procurement Systems  

We are set on a disastrous course. Governments must accept that the way we use energy must change and that a painful period of adjustment lies ahead. The energy efficiency of energy use and procurement should lie at the heart of decision-making and a good starting point is to ensure that reliable efficiency data is available to guide this process.
Energy efficiency now supposedly lies at the heart of EU and US energy policies. Whilst we are most aware of the merit of energy efficiency of energy consumption, e.g. fuel-efficient cars and well-insulated buildings, the concept of energy efficiency of energy procurement is one that has been largely overlooked. One reason for this has been the vast energy surplus provided by historic supergiant oil and gas fields of the Middle East, Russia and the Americas and vast surface coal deposits of Africa, Asia and Australia. As production from these historic fossil fuel deposits starts to decline, the OECD economies are being forced to procure energy from other sources such as wind, tidal, solar, bio-fuel and nuclear. Without most of us being aware of the fact, it has suddenly become important to understand the energy efficiency of new energy procurement systems, if industrial society as we know it is to survive the next great energy transition away from fossil fuels. The Energy Return on Energy Invested (ERoEI) provides one measure of the efficiency of energy procurement and is quite simply defined as:

Energy procured / Energy used to procure energy


The chart shows how the proportion of net energy available for society to use varies with ERoEI. There is in fact much uncertainty in the data displayed and many large gaps in knowledge. 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. With falling ERoEI <>The chart is not zero scaled and shows that for ERoEI = 1, no net energy is produced. The yellow arrow, pointing to ERoEI = 9 is intended to provoke some debate since we do not know with any certainty what the minimum ERoEI for modern industrial civilisation is.

One thing that we do know for sure is that we have used a significant proportion of the easy to access fossil fuels and that new resources scheduled for exploitation will require much larger amounts of energy to procure. The average energy pool available to the global economy is therefore relentlessly marching towards lower aggregate ERoEI.

As society uses more energy to procure energy, an inevitable consequence is that less energy is available for everything else, in a stable energy production environment. Certain areas of current energy use must fail and the way the free market is trying to resolve this problem is to select energy intensive industries for extinction, for example air travel and motor vehicle manufacture, however, current Government policies are trying to prevent this natural selection process, propping up the motor industry on both sides of the Atlantic, expanding airports, whilst subsidizing inefficient means of procuring energy such as temperate latitude bio-fuels.

We are set on a disastrous course. Governments must accept that the way we use energy must change and that a painful period of adjustment lies ahead. The energy efficiency of energy use and procurement should lie at the heart of decision-making and a good starting point is to ensure that reliable efficiency data is available to guide this process.

• Some ERoEI data sources wind, tar sands, ethanol, solar pv (pdf file) and references therein. Nuclear: M. Lenzen, Energy Conversion and Management 49 (2008) 2178–2199. Hat tips to Will and Nate for solar and nuclear sources. 

See also: 
 Ea O Ka Aina: How Civilization will Collapse 4/16/09
Island Breath: The Bad, The Worse and The Seriuouslt Ugly 4/14/08


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