EROEI or IOU
?
Energy Returned Over Energy Invested – a concept introduced
in a paper by Dr John Morgan, which I found in Principia Scientific under the heading The Catch-22 of Energy Storage. I was sure that it would not
only make me sit up and consider its possible implication for all matters of
energy provision, and republished it as Reality Check #6 on my blogsite.
This made me reach for what I still think is one of the most
important books on energy:
Basic Books, New York, 2005
Having now recapped
on Huber & Mills, together with some further looks at what is available
online about EROEI, I could not help thinking that there ought to be a better
way to come to understand this concept – like knowing that ‘a picture is worth a thousand words’ rather
than words alone. So here goes with some
thoughts in that direction.
EROEI expressed as a formula would look like this: ER / EI = U, where U denotes a measure of Usefulness
(for humans). We can leave out the E, because shown thus it really applies not
only to all human activities, but also to all events in the universe, come to
think of it, leaving us with R/I=U. Simplifying further in simple IN and OUT
concepts, we are left with O/I=U when following the EROEI acronym sequence.
But that irks me, because
a)
on a timeline, Input must always precede Output. Time Fact.
b)
When then written I/O=U, we become immediately
aware that the Input ‘I’ must always, and without exception, exceed the Output ‘O’
in order to achieve any Usefulness ‘U’. Thermodynamic Fact. In other words, the
investment ‘I’ is always borrowed, resulting in an IOU to the environment – but
will show as such only when we set the input boundary at this ‘Mother Nature’
level. [For practical purposes see the further discussion of FOWI and Output Tentacle A when I come to Octopus Diagrams]. Therefore, the description for the formula for
calculating should always be known as I/O=IOU, and shown and used as
IOU=I/O
c)
The formula IOU=I/O also provides not only a
familiar acronym for this method of calculating ‘usefulness to humans’ as in ‘IOU’ [I owe you], but also provides an
instant reminder that whatever energy we use, we also owe it to the environment
which provides it for us – however closely or widely one chooses or is forced
to consider the term ‘environment’. We can only transform whatever we find, and
live with the inevitable entropy losses when extracting and converting energy
sources for usefulness. No human, however sapiens,
has yet ‘created’ any energy ab initio,
or is ever likely to.
“The Creation speaketh an universal language,
independently of human speech or human language, multiplied and various as they
may be. It is an ever-existing original, which every man can read. It cannot be
forged; it cannot be counterfeited; it cannot be lost; it cannot be altered; it
cannot be suppressed. It does not depend upon the will of man whether it shall
be published or not; it publishes itself from one end of the earth to the
other.”
Staying with energy matters, we need to use measurements and
dimensions for them. For purposes of measuring energy (and work and heat) the
SI unit is the joule (which in turn is short for Nm). I prefer here to use kWh because everyone is
used to these from their energy bills – and multiplied by the cost charged for
their kWh on everyone’s respective utility bill in any location and situation, gives an
instant feel for the amount of energy under discussion and their incurred
costs.
So, from dimensional consistency requirements, we measure
IOU as I/O=IOU
or kWh/kWh=kWh. So
the value IOU always has a dimension which should be stated.
But kWh ǂ
kWh, they come in vastly different forms and qualities; for example, a barrel
of oil delivered to your door may well contain about 1650 kWh in thermal
energy, but you can’t run your television with it. Unless the QUALITY of U is
known, described or even specified for its actual or intended use, the whole
concept of IOU, or EROEI for that matter, or indeed any other discussion about
uses of energy, is just about meaningless.
So, what does IOU actually mean when calculated as in I/O=IOU?
·
It is a measure of the INPUT COST for one unit
of useful benefit when both are measured in energy terms.
·
the kind of, and the dimension always needs to be
quoted, both for input as well as for output.
o
In the laser example shown below, the usefulness
IOU is the cost of energy input when converted
from oil (ex well head, say) in terms of kWh (thermal) to achieve a single unit
in terms of kWh (power) in the form of laser photons. In the example
illustrated, the IOU cost is IOU=I/O=330 kWhth.
o
For the same amount of usefulness provided
by 1 kWhp converted from the direct output of electrons ex solar PV
panels on the roof would certainly be different for an IOU= ? kWhp.
Unit dimensions,
kind and descriptions for all three terms in the formula IOU=I/O always need to
be stated or remain useless. Back to
your utility’s energy bill: both gas and
electricity consumptions are measured in kWh, but you certainly would not like
your gas kWhth to be charged at the same rate as your electricity
kWhp.
For a hunter-gatherer, Usefulness would mean finding enough
berries, vegetables, and killing enough deer or other animals to feed himself, plus
fending for family, shelter, clothing, firewood, provided from the quality of
flora and fauna, and area of roaming range etc. Here is the energy pyramid for
this situation:
IOU=I/O=
~140 Btu/m2/year
A hunter-gatherer would be an omnivore, let’s say halfway
between a herbivore and first-level carnivore, to find his physical strength
and stamina for his only input, giving an IOU ratio of 150000/1100=136.4; here
measured in Btu/m2/year; which when used on both sides of the
equation still gives a valid ratio between input and output. But again, the
QUALITY (kind) of input needs to be known or specified; here we start with
Plants – not with, say electrons coming directly from a solar PV panel. And another
measure appears: area of land required as ‘input’ for plant-life energy. So
even our single hunter-gatherer level human is, in energy terms, permanently in
hock to the environment to the tune of, say 140 times his own possible adult input
valour. The term ‘environment’ can be any four-dimensional region (time always plays
a role, even when kept tacit) between the tip of your nose and the furthest
region of the universe; we are all just stardust on that ‘boundary’ assumption.
A realistic boundary needs to be defined before making meaningful comparisons
between different situations – to be discussed below.
At the other extreme of a situation to be assessed,
providing 20 kWh of laser quality photons for, say eye surgery, requires app.
6,600 kWh thermal energy at start of the chain of conversion and refinement
necessary from coal, oil or gas, that is I/O=U
or 6600/20=330/1 or an IOU ratio
of 330 kWh Input for every single kWh of laser output.
Again, this is most intuitively understandable when shown graphically:
IOUkWhp=I/O=330
kWhth
One last example for comparison: the SUV version of the horseless carriage:
The author’s 2% stated usefulness
from the original oil source, giving an
IOU=I/O=132 kWhth
Where does all this Input energy disappear to with so little Output
energy ending up as Useful for us humans? Best illustrated with Sankey diagrams [try http://www.e-sankey.com/en/].
Here
is the first one I ever saw, created in 1949 showing the World’s Energy Flux in
1937:
When I first saw this, I was reminded of seeing an octopus
and called it an Octopus Diagram, with the octopus’ head at the input end at left, and the tentacles on the right, in between digesting and distributing
everything that the various mouths at
the head can gobble up. cf.
http://altenergymag.com/emagazine.php?art_id=1673
The other advantage is the possibility to arrive at boundary
definitions for arrival of energy sources at the various ‘mouths’, from where
they enter the octopus’ digestive system.
Perhaps a simple convention for all entry boundaries could
be the first entry level to wholesale points, Free
at Top-level Onshore Wholesale Intake
– FOWI perhaps – from where only direct distribution levels, routes and conduits
to reach any end user depart, albeit via further intermediate refinement and
conversion operators and processes [most notably for electricity generation, as
identified in the US 2009 diagram below].
If on further scrutiny, FOWI would form a practicable
boundary definition for the ‘food’ intake at the various mouths of any Octopus,
it would also be the point of total energy expenditure needed to provide its
different kinds of ‘food’, in order to arrive from whatever source found in the
environment at a comparable level of entry into the Octopus’ metabolism.
One entry shown in the 1937 World Energy Octopus is the tentacle
labelled A in the black CONSUMED box at the output end of the diagram, labelled
‘extraction of raw materials’.
I propose to retain a
tentacle A as in this 1937 Octopus of energy use perhaps as label A1 because it
is, after all an output used, and not just as ‘extraction of raw materials’ but
including all energy expenditure for ‘food’ right up to the ‘mouths’ identified
as FOWI gates. A1 uses need to be known when used for calculating energy
embodiments in their respective primary energy headings by the time they arrive
at FOWI input boundaries. Further tendrils at tentacle A, say as A2. A3…
An might collectively be described as Culture uses, which would include headings
like education from kindergarten to university and beyond, science, fundamental
research (Iter, Cern, Fusion etc), all of the Arts, leisure activities, etc etc; in short anything using energy
not suitably classifiable as belonging strictly under headings like Electricity
Generation, Residential, Commercial, Industrial and Transportation as categorized
in the 2009 US diagram.
One fundamental other resource is needed for our Octopuses just as for any other
creature, including humans, with all their bodily internal and external
transformation processes – and that is
WATER. In discussions of IRREPLACABLE energy sources, often the
use of Peak Oil, Peak Coal appears for any other irreplaceable source peaking and
then beginning to become unavailable for ever.
Yet Water is never explicitly mentioned
in spite of being essential in the extraction, transformation and as processing
ingredient in all primary energy sources and their uses. I have made a
rough-and-ready assessment of the water requirements of electricity production
and came to surprising results, peaking in PEAK WATER becoming apparent. While water is not strictly irreplaceable, – with oceans and polar
ice caps being about as limitless as could be desired – but water will (where
it not already is) become a very energy-hungry resource due to transportation, desalination and waste-water treatment
and purification necessities..
After all, no one has described the essence of the design objective
for all of us, better than Buckminster Fuller in his address to the 1963
Congress of the International Union of Architects in Paris:
".... to render
the total chemical and energy resources* of the world, which are now
exclusively preoccupied in serving only 44% of humanity, adequate to the
service of 100% of humanity, at higher standards of living and total enjoyment
than any man has yet experienced."
*I think we
should include information resources
Back to the original Octopus version, figures for which are
given in Millions of Millions of Kilowatt-hours/year (1937).
During that year, the world used – for other than food –
(0.3 +0.2 +1.8 +0.9 +3.6 +0.1 +0.7 +10.9)
=18.5^12 kWh/y , of which (0.3+1.8+0.8+0.8)=3.7^12 kWh/y were useful, giving an
IOU=5^12 kWh/y, or as plain ratio
with identical I and O dimensions assumed, an
IOU=5.
Overall, during that year the World Octopus gobbled up (7.0+16.2)
= 23.2 trillion kWh and ‘excreted’ (23.2-3.7) =19,5 trillion of these, that is a
seeming ‘waste’, but better called
entropy* = 84%
because that ‘waste’ is not wasted:
without it there would be NIL output;
useful output
= 16%
* Entropy is a thermodynamic property that is a measure of the energy not
available for work in a
thermodynamic process. It
is defined by the second law of thermodynamics
A more recent Sankey
diagram for US energy in 2009:
IOU=94.62/39.97= IOU = 2.37
entropy is 54.64/94.62= entropy
= 58%
useful
output = 42%
These two diagrams are different in size, time and
construction and are not strictly comparable in detail, kind or volume, but seen
as a type comparison, they do show,
that the US had about half the IOU ratio of energy drawn from the environment
with an efficiency of conversion processes of ~40% useful output with ~60% incurred
entropy losses, compared to the whole World conversion process (1937) showing
an efficiency of ~20% useful output with
~80% incurred entropy losses from an IOU ratio of energy drawn from the
environment
about twice that of the US 2009 situation.
about twice that of the US 2009 situation.
A notable difference between the two Sankey diagrams shown, is that US 2009 does not contain any mention of Octopus mouths for Food and Fuel for which, say artificial fertilizers amongst other needs for processes might be seen as a significant energy input requirement. In the discussion of water needs below, agriculture would be a major contributer to Peak Water.
There is one other enlightening use of octopuses. Using the
2009 US diagram, the annual Residential consumption is shown as 11.26 Quads/y,
derived from (0.01 +8.35 +2.68 +0.7 +0.37 +23.37 +19.76 +3.88) = 59.12 Quads/y
applicable national primary inputs. Some assumptions here: Residential is taken
to include everything from construction, use and maintenance and demolition
during that year. The pure lighting use is probably no more than 1% of that
total, but is pure electricity. It is therefore arriving from the inputs to
Electricity Generation of 38.19 Quads/y. Saving 1% (assumption, here purely for
illustration purposes) of residential energy use from changing ‘lightbulbs’
would save 1.126 Quads/y [that is equal to 329,998,039,833 kWh/y, or 330 billion
kWh/y] out of 38.19 Quads/y, or 0.3% of national electricity production costs
in energy terms. Out of total national
primary energy, those 330 billion kWh/y saved would represent a national saving
in primary energy of 1.126/59.12 = 0.2%. This is just to illustrate one other useful
aspect of making use of Sankey diagrams by following any end (or inter-process
stage) use upstream to see what effect any
change will have on primary input.
I would like to quote from the inside cover blurb of this ‘Basic Book’ that triggered me to think
of octopuses and IOUs:
“For all the talk about energy prices, and energy policy on both sides
of the political aisle we actually know very little about what’s really at stake.
In their explosive new book The Bottomless Well, Peter W Huber and Mark R Mills
shatter the prevailing myths and show that across the board, energy isn’t the
problem – energy is the solution.
Writing in take-no-prisoners, urgently
compelling prose, Huber & Mills
explain:
-- why
demand for energy will never go down
-- why most of what we think of
as “energy waste” actually benefits us
-- why more efficient cars,
engines, and bulbs will never lower demand
-- why energy supply is
infinite
-- why gasoline prices matter
less and less
-- and
why hybrid engines will most likely lead us to cars propelled by the
coal-fired
and uranium-fired grid.
As for the much-maligned power grid itself, it’s the Worst system we
could have except for all the pro-posed alternatives. Expanding energy supplies
mean higher productivity, more jobs, and a growing GDP. The Bottomless Well
shows how a better understanding of energy should radically change our views
and policies on a number of highly controversial issues.
I hope this trailer sounds
intriguing enough to make you reach for this book, from which all illustrations
but the US 2009 diagram, have been borrowed.
WIRED magazine
[UK Edition OCT 14]
provides, as always, fascinating reading; making inter alia no less of an
announcement on the front cover than:
SOLVED! THE
GLOBAL FOOD CRISIS
Enticing no doubt, but would be digressing
here because on page 139 surfaces an article by Jeremy White [WIRED’s Product Editor]
from which I would like to quote an excerpt relevant to the IOU discussion
here:
POWER PLANT
When BMW began making electric and hybrid
cars, it also rethought what its Leipzig factory should be.
you might call it post-fordist…
“From Henry Ford’s industrial production model to the introduction of
robots in the late 20th century, there has been significant change
in the way mass-market cars are made….
Take BMW. The German company was aware that the assembly of its i
Series of electric and hybrid vehicles (the i3 was launched in November 2013,
the i8 in June this year) required a new approach to manufacturing. So, between
2009 and 2012, it spent €400 million (£310 million) building a new factory near
Leipzig in east central Germany.
The company claims that the facility, which covers an area of 2.1
million m2, is one of the most sustainable automobile plants in the world. The differences
with the older plants are striking. On the new line, there is no need for a
paint shop as the thermoplastic outer body panels can be sprayed in small,
shed-like rooms. A traditional press shop is absent because the construction of
the passenger section of the vehicles doesn’t require steel or aluminium. In
the body shop, there is no more welding, just robots silently applying glue.
The result is that making the i models requires 50 per cent less power
and 70 per cent less water per car compared to the BMW production average which,
in 2011, was 2.43 MWh per vehicle. All of the electricity needed for the i
models is generated on-site using wind power from four 2.5 MW turbines.
Generating around 26 GWh per year, these turbines produce 2GWh more electricity
than is required for the i Series. The surplus is channelled into other areas
of the plant….”
WOW, I thought what a topical
real-life example for exploring with IOU analyses: an on-site windmill powered industrial plant,
usually thought of necessarily being hooked to that ‘baseload grid’, producing
surplus energy for export, perhaps on a 24hour production basis (?) using what
(?) for wind power variability bridging, comparing its installed IOU with the
same 26 GWh/y output derived from Baltic or North Sea offshore wind, or from a
possible grid connection, or what-if from solar PV perhaps on factory roofs –
using the IOU calculation method here described together with the graphical
views like the Pyramids and Octopus diagrams to compare and understand the
various options?
Have some fun with that :-)
I can see a liberal necessity for ‘midnight
oil’ coming up…
ooo000ooo
ADDENDUM
Added on 16 March 2015:
On 17 January 2015 The Economist published a
Special Report on Energy and Technology. The
first article in this report, headed Let there
be light included this Sankey
diagram
Source: The Economist 17 JAN 2015, Special
Report: Let there be light
IOU = I/O = 97.14/38.4 = IOU
= 2.63
entropy is 59.0/97.14 = entropy = 61%
useful
output = 39%
Converting
all energy units to TWh as in the first Octopus
for the World Energy use in 1937, we can make the following comparison:
WORLD 1937
Total
IN: 23.2 TWh = 100% IOU = 5.49
Useful
OUT: 3.7 TWh = 16% entropy = 84%
USA 2009:
Total
IN: 94.62 Quads = 27 730
TWh = 100% IOU = 2.37
Useful
OUT: 39.97 Quads = 11 714 TWh = 42% entropy = 58%
USA 2013:
Total
IN: 97.14 Quads = 28
469 TWh = 100% IOU
= 2.53
Useful
OUT: 38.40 Quads = 11 254 TWh
= 39% entropy = 61%
Which
together show these useful order-of-magnitude comparisons:
-- in
2013, the USA alone consumed 1227 times as much energy as the whole World did
in 1937, with a 231% improved conversion
efficiency (measured by the IOU ratio, after the 2.9 TWh used for ‘food’ in the
1937 world total – not used in the USA diagrams – has been allowed for)
-- USA
consumption had increased by 2.66% since 2009, with a 7% entropy increase over 2009 (= loss
in conversion efficiency = IOU ratio).
ooo000ooo
[1] PS added 01 DEC 2014
Oxford University Press Inc, New York, 2007
Addendum 07 July 2016:
Since writing this essay about
three years ago, the IOU concept has led to further insights from a fuller understanding of
Peter Atkins' FOUR LAWS when combined with the BIRTH OF THERMODYNAMICS at http://cleanenergypundit.blogspot.co.uk/2015/07/thefour-laws-withoutwhich-nothing.html ,
which in turn led to an
expanded edition of SUSTAINABILITY – THE FULL MONTY,
published by Lulu Press at http://www.lulu.com/spotlight/CleanEnergyPundit
All of which finally allowed me to arrive at a definition of SUSTAINABILITY, now added to the earlier definition of CLEAN ENERGY
And not to forget: 'sustaining itself in future' is, of course, the ultimate definition of
WEALTH.
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