The above graph is adapted from Limits to Growth, Revisited. It is not a hard and fast prediction, but rather the product of a model with 40 years of high correspondence with developments. We are, at present, at the top of the growth curves, many of which have already begun to plateau. Slopes of decline do not factor in such worst-case scenarios as widespread urban- or domestic nuclear facilities collapse consequent to economic collapse.

I've added the shading and 'crossover' circle' (coincident with 'peak everything') to indicate my best guess as to the high probablility zone for global, economic collapse, triggering the onset of TEOTWAWKI.

I fear a hard landing... no 'reboot' or 'transition' to a lower functioning economy. I urge high priority preparation now.

I've got a short glossary of terms at the bottom of this page... if you come across an unfamiliar term, please scroll down and check it out.

Information I'm including or pointing to doesn't mean I necessarily agree with it. Rather, I've found it to be stimulating and worthy of consideration. I'm sure you'll exercise your own judgement... we're nothing if not independent! 8)

Friday, November 8, 2013


EROEI: Energy Return On Energy Invested

I didn't hear this term until relatively recently, but when I did, it rang a bell.

EROEI is a measure of net gain. As ER and EI are always positive numbers, EROEI must also be positive. But an EROEI of one (where ER equals EI) is a watershed, break-even value. For values greater than one, a net gain is achieved. Values between zero and one represent net loss.

Any (local) venture - be it a hummingbird, a steam shovel, a corporation - with an EROEI substantially greater than one tends to thrive. With an EROEI close to one, it's living on the perilous edge. An EROEI between zero and one, and it's operating at a loss.

In an economy that depends on growth, if we're not getting more out than we're putting in, we're on Skid Row.

I find it to be a dang useful concept in life, as a focus of assessment, for just about any decision. Energy is a catch-all term... expenditures of time, effort or  assets, had best bring a return (I'll accept pleasure, joy and yum as countable toward the ER side!).

But in TEOTWAWKI circles, it is often noted that the EROEIs of 'fossil fuels' - those miracles of useful energy - are dropping like rocks in the post-peak-everything environment. Ditto for virtually anything, including the 'harvest' of renewable resources. Despite advances in extraction technologies, we're spending more and more energy to extract each calorie.

NOTE: Fracking is not an exception. Even early data confirms that it is following the same EROEI curve as any other limited resource. One expects BOTH initial boom AND eventual bust. As demand continues to grow exponentially, the curve can't help but compress.

I have some questions...

EROEI is a context number. ER is fairly straightforward. Let's say the energy equivalent of a barrel of crude. But what we accept as the EI is critical to the full result. Do we mean energy required for extraction machinery? For transport (including the pro-rated transport infrastructure?)? Refinement? Transport, again? 

It's hard to imagine that the numbers include much more than these, and I've not heard if there's even that much.

But there is more... the so-called hidden costs

How much to feed, clothe and transport workers all along the way? How much goes to infrastructure necessary to use the fuels (pumping stations, roads and automobiles; railways and trains; ships, harbors, nav aids and shipyards; power plants and factories, homes and other clients of the grid? How much to loss; to spills, inefficiency and entropy? How much to remediation (evironmental impact and clean-up, medical costs related to pollution, accidents, etc.). Ultimately, how much to climate change, ocean acidification and rise? Every barrel we extract has a share in each of these.

This is supposed to be a plus-sum game. GROWTH = ER > EI, right? So long as EROEI > 1, we're okay, right? Right??

But if EI is grossly underestimated, what then is our trajectory?

Note: It's interesting to note that sustainability depends on an EROEI of one. Neither growth nor its opposite are sustainable for a successful species.

1 comment:

  1. Astute reader JOHN picked up on my confusion between ER and EROEI.

    Whereas I had written:

    > EROEI is a measure of net gain. Any venture - be it a hummingbird, a steam shovel, a corporation - with high positive EROEI tends to thrive. With neutral (low to equal) EROEI it's living on the perilous edge. Negative, and it's operating at a loss.

    John points out:

    > This is a minor detail which doesn't really affect the accuracy or importance of your major points, but since both the numerator and the denominator of EROEI are both positive numbers, EROEI must also always be a positive number.
    > The water-shed number for this equations is ONE (not ZERO), which is the point where Energy delivered and Energy absorbed balance each other. A restatement of your above statement might read:
    > "Any venture - be it a hummingbird, a steam shovel, a corporation - with an EROEI substantially greater than ONE tends to thrive. With an EROEI close to ONE it's living on the perilous edge. An EROEI between ZERO and ONE, and it's operating at a loss."

    Absolutely correct!. I had misunderstood EROEI to equal ER MINUS EI, rather than ER OVER EI. Sloppy reading! 8)

    Since I do consider this to be such an important concept, I've
    corrected the post, rather than leave buried in comments.

    Thanks for the feedback!

    Dave Z


Hey Folks... I'm not in a position to moderate comments. If discussion remains respectful and on topic, I welcome comments (passion okay). If it spins out of control, I'll have disallow them... I thank you for your civility.

I've opened comments to all 'Registered Users' (whatever that means!) to help weed out pesky spam.

- Dave Z