E&P = Exploration and Production, from Hart Energy Publishing, 1616 S.. Chapter 12A Framework for Energy Alternatives: Net Energy, Liebig’s Law and Multi-criteria Analysis Nathan John Ha
Trang 1288 E Kesslerhighest levels of government, it is often proclaimed that our problems will be solved
by research, even when the speakers have little knowledge of either science or itsnatural limitations.33
Much legislation provided by the political system in the United States is an change for financial contributions to campaigns Will our system (and others, too)remain inadequate to deal with the global warming and energy decline phenom-ena? If it does remain inadequate, it will not be because the U.S system is vastlydifferent than it used to be – although there has been concentration of control ofmedia by narrow interests, this control over news delivery has been somewhat off-set by democratizing effects of the Internet Historically, our political system hasfrequently supported powerful groups that sacrifice the good of a large sector forpersonal short-term benefits This author thinks that the last times that populace andgovernment rose to needed heights was when the critical nature of conditions related
ex-to WW II became more than obvious And subsequent ex-to WW II there was the goodMarshall Plan
In the United States and elsewhere, many research programs are well funded
As noted in a short article (Kessler, 1991), the political establishment is pleased toprovide the wherewithal, in part because the hope for favorable outcomes is a basisfor postponement of actions that are politically difficult to implement even thoughthey could be immediately effective And, of course, research must be encouraged;
a plethora of research outcomes in every field of study are the principal basis forour industrial and postindustrial worlds, and further highly favorable results seeminevitable
For example, a recent helpful outcome in Japan has produced light emittingdiodes (LEDs) that are about 50% efficient in their production of light from electri-cal energy, and the cost of LED production is being reduced rapidly LEDs may be
on track to replace both incandescent lights with efficiency about 5% and cents, 25% The U.S Dept of Energy has estimated that about 22% of electricityproduction is devoted to lighting, so the new products may lead to both reduced CO2emissions and better lighting around the world, including in communities remotefrom utility power (Ouellette, 2007)
fluores-Important developed differences between now and decades ago are more in thenature of our times than in qualities of our political system General demand hasrisen and continues to rise with increasing world population, and some basic re-sources that are essential to maintenance of infrastructure and provision of essen-tials are not as plentiful as formerly and are more expensive to obtain The immensepower of tools created by spectacular advances in science and technology means thatmalfeasance in the application of those tools leads to increasingly harmful conse-quences Thus, private automobiles have provided unprecedented and very welcomemobility to many, but they are still being promoted even though they are principalcontributors to carbon dioxide emissions and decline of liquid fuels While products
33 Of course, some problems are solved by research, but many of the political pronouncements about expectations from scientific research reflect more faith than science.
Trang 211 Our Food and Fuel Future 289
of advanced science and resultant technologies are essential to most of our dailylives, many more people in the United States than in Europe seem to reject findingsand implications of science when those findings conflict with historical matters offaith or call for specific short-term sacrifice for dimly-perceived benefits in the longterm
Science and technology are seen as the major source of means for tapping thewealth of Earth To what extent may further advances lead to means for markedreduction of our impacts? Such favorable developments will depend much more onscientific guidance to research directions than on political guidance!
Geometrical orientations of Earth to Sun are projected to rule out global coolingand recurrence of glaciations for another 30 thousand years, and this means thatglobal warming will continue inexorably unless emissions of greenhouse gases aregreatly diminished or there is an unexpected diminution of Solar radiation or ex-tensive volcanism on Earth Therefore, it may well be that within a few decades,humans on Earth will have to accommodate powerful forces that will make earlyadjustments seem easy by comparison New problems may well include migrations
of millions of people forced to leave submerging habitats, shortages of water inareas now dependent on glacial runoff, hotter summers, fluctuations of food supplyfollowing intensified droughts and floods, and increased social unrest There aresolutions to global warming problems, but none is easy, and most political systemsare inhibiting Will we humans meet this immense challenge to our established waysand cultures? Delay compounds difficulty and cost of solutions
11.6 Conclusions
The United States has not yet a single program effective toward reduction of itsdependence on foreign sources for liquid fuels or toward mitigation of the loom-ing disaster represented by global warming If existing programs were effective,
we would expect that imports of petroleum products would be declining, but suchimports are continuing to increase And the existing biofuels programs are alreadydamaging the agricultural economy In large part, the programs in place are a con-sequence of a political system whose legislation is too-much based on contributionsfrom the already rich and powerful, and insufficiently responsive to conditions andfindings from advanced and still burgeoning science and technology Overall, thesituation is a consequence of the human condition, little changed during thousands
of years.34
Such programs as improved insulation of existing houses, new construction of
“green” buildings, and facilitation of transportation alternatives such as bicycling,are steps in right directions and have won grass-roots support, but all are far too
34Characterized in part in Sophocles, “No thing in use by man, for power of ill, can equal money.
This lays cities low, this drives men forth from quiet dwelling-place, this warps and changes minds
of worthiest stamp, to deeds of baseness, teaching men all shifts of cunning, and to know the guilt
of every impious deed By base profit won, you will see more destroyed than prospering ”
Trang 3290 E Kesslersmall The major programs, ethanol from corn and sugar cane and biodiesel frompalm oil, soybeans, and canola are deceptive responses They provide short-termprofit to special interests and they do provide fuels, but even the aggregate amount
of fuels produced in these programs is a trivial proportion of present consumptionand, the production processes yield, at best, no net reduction of carbon dioxide emis-sions The alternative fuels programs damage the agricultural economy by causingincreases in the price of corn and other human foods and livestock feeds, losses ofalready diminished habitat including tropical rainforests and wildlife, and losses oftopsoil and increased stress on water supplies
As noted above, unless carbon dioxide emissions are quickly reduced, globalwarming will be a very serious matter for future generations and will force large ad-justments in ecosystems worldwide Concern rises because in the United States and
in rapidly developing countries such as China and India, policies remain stronglyoriented toward economic and even physical growth with increasing emissions ofcarbon dioxide
What should be done in the United States, for example, beyond such programs
as tightening CAF ´E35 standards, weatherizing homes and utilizing energy-savingconstruction in new work, installing solar heating, and expanding use of time-of-daypricing of electricity, all of which are or would be good though inadequate? A properpractical course is difficult to identify, and an effective course may be impossible toidentify In other words, it may be too late to avoid serious damages from globalwarming and to preserve social order in face of fuel declines But, we must keeptrying, and it is clear enough that in order to confront consequences of global warm-ing and decline of liquid fuels, societies in developed (and developing) countriesmust practically be turned on their heads! And if they do not turn themselves soon,they will be turned later by large forces beyond human control
As a first step, the notion of continuous economic growth must be abandoned,36and global population, which has increased threefold in your author’s lifetime, must
be much reduced Whatever else is done, if population growth proceeds, all othersaving actions will be nullified and even overwhelmed owing to increased demand.Abplanap’s succinct statement (1999) applies, necessary changes being made, tophysical growth of many entities in the presence (or absence) of technologicaladvances: “ Any kind of agricultural ‘green revolution’ which is not accompanied
by effective population control merely resets the limiting parameters at higher levelsand enables countries with a large proportion of starving citizens to increase theabsolute numbers of starving people”
Is population reduction feasible? Population is sustained with an average birthnumber near 2.1 per female inhabitant If this average were reduced to 2.0 the impact
on individuals would be very minor but the eventual impact on world populationwould be major If world population were to decline just one percent per year,
35 Corporate Average Fuel Economy, i.e., average automotive mileage as mandated by federal legislation.
36 And replaced by increased learning, cultural growth, equity and justice A tall order!
Trang 411 Our Food and Fuel Future 291numbers would be reduced by half in 70 years and again by half in another 70.
In 2007, this must be seen as only a utopian dream, since the large proportion ofyoung people in the present world population guarantees substantial growth of theglobal population in the near term.37 Further, strong diverse forces, even the U.S.government at this writing, offer little or no support for birth control,38 and Cham-bers of Commerce all across America promote growth among the highest of theirpriorities Of course, population matters are very different in different economies,demographies, and cultures, and associated problems, including treatment and edu-cation of females, are not explored here.39
Second, it would be helpful in the United States to have a massive shift in fundingfrom highway building to construction of a national rail system for both passengertravel and improved freight transport Such a system, emulating that already in placeand still under rapid development in Europe and somewhat too in Asia, would beinherently more energy efficient than automobiles and truck travel on highways, andeven further emission reductions would be achieved to the extent that trains becomemore fueled with electricity from overhead wires or from liquefied natural gas inplace of diesel fuel
Such a transportation alternative in the U.S might be paid for in part by an creased federal tax on gasoline and diesel fuels If rail were more emphasized, U.S.highways would be less burdened with cars and trucks, highway maintenance costswould decline, and emissions of carbon dioxide and health-threatening gases fromthe automotive sector in this leader country would decline And decline of trucktraffic would quicken if trucks were taxed in relation to the maintenance costs theyimpose – road damage is proportional to the fifth power of axle weight.40 Groups
in-of citizen-activists are working in these directions, but during 2007 in the UnitedStates, there is little official interest in such programs – indeed, such programs lacksubstantial support from the federal level in the United States and are opposed byhighway and automotive lobbies In 2007 there is still strong political support towardexpansion of the highway system
Third, further enhancement of already burgeoning communication technologiesmay proceed to a level that somewhat reduces energy-consumptive travel
The three items above could be resource-conserving approaches in a relativelyshort term But for true sustainability in terms of geological age, we should, barringsuccess with nuclear fusion as a source of electrical energy, begin to explore devel-opment of a very broad solar economy, because only solar energy is projected toendure much as at present for billions of years This means that solar power plantswould be built with help from fossil or nuclear fuels to support an economy with
37 Barring more serious war or pestilence, of course.
38 China has learned the hard way, and brutality properly opposed is a sometime component of birth control efforts in China, but the United States government declines to acknowledge the seri- ousness of population numbers even when those numbers strain the food supply.
39 Nor have we discussed abatement of terrorism and war and spread of justice internationally.
40 In Oklahoma, the tax on diesel fuel as this document is prepared is three cents/gallon less than
on gasoline.
Trang 5292 E Kesslerfewer human numbers indefinitely, and the solar power would be used to maintainand enhance the power system itself This vision of a farther future is mentioned
by Patzek on his website and a possible solar path has been detailed by Zweibel,
et al (2008)
So, in summary, What is our food and fuel future? It is highly problematic, and adecent future for humans is much dependent on rationalization of decision-making
at all levels to findings and implications of science and technology! The rapid pace
of change in this 21st century also calls for a much more rapid response of properdecision making to major findings of science and technology
Will humanity on Earth be a “flash in the pan”? Consider a 30-volume clopedia, each volume with one thousand pages, each page with an average onethousand words Let these thirty volumes present a linear history of Life on Earthsince multi-celled organisms became prevalent perhaps one billion years ago, withthe start of accumulation of the fossil fuels that we humans use today How muchspace is devoted to the sixty-five years since World War II, during which we humanshave extracted about half of Earth’s readily extractable liquid fossil fuels and muchcoal, and caused an astonishing increase in atmospheric content of carbon dioxide?
ency-Is the answer disturbing? Only two words on the last page of the last volume! Howlong will we endure and how much space might describe our future post-industrialsociety?
Acknowledgments Thanks to Marjorie Bedell Greer and Richard Hilbert for suggestions based
on their readings of an early typescript, to Hilbert and to Charles Wright for sociological insights and to Tom Elmore for imparting some of his encyclopedic knowledge of the railroad history
of Oklahoma David Sheegog contributed to the discussion of ethanol, and Steve Shore helped with the table in Section 11.4 Before semi-retirement, Dr Greer was a professor of anatomy at the Oklahoma University Health Sciences Center in Oklahoma City, Dr Hilbert was Chair of the Sociology Dept at the University of Oklahoma in Norman, and he continues to lecture, and Charles Wright is an attorney and sociologist Tom Elmore is Executive Director of the North American Transportation Institute, Moore, Oklahoma, David Sheegog is a psychologist and rancher, and Steve Shore is a professor of chemistry at Oklahoma City Community College Thanks also to David Pimentel for several important suggestions.
References
Abplanap, P L (1999) A letter to Technology Review, Sept–Oct.
American Wind Energy Association (2007) http://www.awea.org/projects/, retrieved August 28, 2007.
Anthony, R (2007) Safe at Sea, Spectrum, Massachusetts Institute of Technology, XVIII, X, 17.
Apricus.com (2007) See this webpage, http://www.Apricus.com, Retrieved Dec 3, 2007 Bullis, K (2006) Abundant Power from Universal Geothermal Energy, http://www/ technologyre- view.com/Energy/17236/, retrieved Oct 11, 2007
Castro, F R (2007) The Internationalization of Genocide, Granma Internacional, April 3.
Center for Rural Affairs (2007) Monthly Newsletters from P.O Box 136, Lyons, Nebraska 68038–0136.
Clery, D (2006) ITER’s $13 Billion Gamble, Science, 314, 5797, 238–242.
Congressional Research Service (2005) Alcohol Fuels Tax Incentives, CRS Order Code RL2979.
Trang 611 Our Food and Fuel Future 293
Crabtree, G W., Dresselhaus, M., & Buchanan, M V (2004) The Hydrogen Economy Physics Today, 57, 12, 39ff.
Crabtree, G W & Lewis, N S (2007) Solar Energy Conversion Physics Today, 60, 5, 37–42 Duncan, M & Webb, K (1980) Energy and American Agriculture From the Research Division
of the Federal Reserve Bank of Kansas City, U.S.A., Thomas E Davis, Senior Vice President 41pp.
Environmental Protection Agency (2007) National Lake Fish Tissue Study, Retrieved 1 Sept and earlier from www.epa.gov/waterscience/fishstudy/ (Much detail has been available on the web sites, and your author has been told that a formal summary report is in review and may be available during 2008.)
E&P (2007) Coalbed Methane, 80, 6, 41–55 (A series of presentations on new and developing
technologies) (E&P = Exploration and Production, from Hart Energy Publishing, 1616 S Voss Road, Houston, Texas, 77057.)
Ghazvinian, J (2007) Untapped – The Scramble for Africa’s Oil (New York, Harcourt) 320pp.
Hansen, J., Sato, M., Kharecha, P., Russell, G., Lea, D W., & Siddall, M (2007) Climate Change
and Trace Gases Philosophical Transactions of the Royal Society A, 1925–1954.
H¨aring, M.O., Ladner, F., Schanz, U., & Spillmann, T (2007) Deep Heat Mining Basel, liminary Results Retrieved August 5, 2007 from website: http://www.geothermal.ch/ down- loads/dhm egc300507.pdf
Pre-Hart Energy Publishing (2006) Unleashing the Potential of Heavy Oil A supplement to E & P Oil and Gas Investor (Principally a description of facilities and investments in the tar sands of Alberta, Canada.) 1616 S Voss, Ste 1000, Houston, Texas 77057.
Hart Energy Publishing (2007) Unleashing the Potential of Heavy Oil A supplement to E & P Annual Reference Guide (A discussion of new technologies.) 1616 S Voss, Ste 1000, Houston, Texas 77057.
Hinze, W J., Marsh, B D., Weiner, R E., & Coleman, N M (2008) Evaluating Igneous Activity
at Yucca Mountain EOS, 89, 4, 29–30.
Intergovernmental Panel on Climate Change (2007) Numerous reports available on the Internet, http://www.ipcc.ch/
Kahn, J & Yardley J (2007) As China Roars, Pollution Reaches Deadly Extremes, The New York Times, August 26.
Kessler, E (1991) Carbon Burning, the Greenhouse Effect, and Public Policy, Bulletin of the American Meteorological Society, 72, 4, 513–514.
Kessler, E (2000) Wind power over central Oklahoma, Report prepared for the Bergey Wind
Power Company, Norman, Oklahoma 2000, x + 25 pp + 46 figures January.
Kessler, E & Eyster, R (1987) Variability of wind power near Oklahoma City and implications
for siting of wind turbines Final Report on DOE Interagency Agreement No DE-A1-6-81RL
10336 Pacific Northwest Laboratory, Richland, Washington September, 74 pp + appendices [This report was reprinted by the Oklahoma Climatological Survey, Norman, Oklahoma, in
1994 in a condensed format with small editorial adjustments and some additional notes.]
Komar, P.D (2007) Higher Waves Along U.S East Coast Linked to Hurricanes EOS, 88, 30, 301.
Lagercrantz, J (2006) Ethanol Production from Sugar Cane in Brazil Retrieved August 10, 2007, from http://www.gronabilister.se/file.php?REF=39461a19e9eddfb385ea76b26521ea48&art= 376&FILE ID=20060511084611.pdf.
Mao, W L., C A Koh, & E D Sloan (2007) Clathrate hydrate under pressure, Physics Today,
60, 10, 42–47.
Marland, G., T.A Boden, & R.J Andres (2005) Global, Regional, and National Fossil Fuel CO2
Emissions, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S.
Department of Energy, Oak Ridge, Tenn., U.S.A.
Mayes, J (2007) Warmest 12 months in British Isles instrumental records, Weather, 62, 4, 86.
McCain, J (2003) Statement of U.S Senator John McCain on the Energy Bill (November 21st) National Academy of Sciences (2007) Water Implications of Biofuels Production in the United States October, 86pp Summaries and the complete report are available on the Internet: http://www.nationalacademies.org/morenews/20071010.html
Trang 7294 E Kessler NOAA (U.S National Oceanic and Atmospheric Administration) (2007) http://www.cdc noaa.gov/map/images/rnl/sfctmpmer 01b.rnl.html
Oklahoma Mesonet (2007) http://www.mesonet.org/public/
Oklahoma Wind Power Initiative (2007) http://www.ocgi.okstate.edu/owpi/
Ouellette, J (2007) White LEDs poised for global impact Physics Today, 60, 12, 25–26.
Pimentel, D., Patzek, T W & Gerald, C (2006) Ethanol Production: Energy, Economic, and
Environmental Losses Reviews of Environmental Contamination & Toxicology, 189, 25–41 Pennisi, E (2007) Replace Genome gives Microbe new identity Science, 316, 5833, 1827 Roach, W T (1998) Can Geothermal Heat Perturb Climate? Weather, 53, 1, 11–19.
Schneider, D (2007a) Coal Futures American Scientist, 95, 4, 314–315.
Schneider, D (2007b) Who’s Resuscitating the Electric Car? American Scientist, 95, 4, 403–404.
Shady Point (2007) Retrieved October 17, 2007: http://www.CO2captureandstorage.info/ project specific.php?project id=22
Shapouri, H., Duffield, J A & Wang, M (2002) The Energy Balance of Corn Ethanol: An Update.
United States Department of Agriculture (USDA), Agricultural Economic Report Number 813 Simmons, M R (2005) Twilight in the Desert (New York, Wiley) 428pp.
Special Section: Sustainability and Energy (2007) Science, 315, 5813, 781–813.
Srivastava, R K., Hutson, N., Martin, B., Princiotta, F., & Staudt J (2006) Control of Mercury
Emissions from Coal-fired Electric Boilers Environmental Science and Technology, March 1,
Tyner, G., Sr (2002) Net Energy from Wind Power Retrieved April 3, 2007 from Minnesotans for
Sustainability website: http://www.mnforsustain.org/windpower tyner g net energy.htm Vago, S (1981) Law and Society (Englewood Cliffs, New Jersey, Prentice Hall) xi + 372pp (See esp pp 132–135)
Wallace, Linda, L (2007) Switchgrass is no energy panacea Essay in The Norman Transcript, on
Page 4, October 11, and personal conversation Prof Wallace is with the Dept of Botany and Microbiology at the University of Oklahoma, Norman.
Weiskel, T C (1990) The Need for Miracles in the Age of Science Harvard Divinity Bulletin,
XX, 2 5ff.
Zweibel, K., Mason, J., & Fthenakis, V (2008) A Solar Grand Plan American Scientist, 298, 1,
64–73.
Trang 8Chapter 12
A Framework for Energy Alternatives: Net
Energy, Liebig’s Law and Multi-criteria
Analysis
Nathan John Hagens and Kenneth Mulder
Abstract Standard economic analysis does not accurately account for the physical
depletion of a resource due to its reliance on fiat currency as a metric Net energyanalysis, particularly Energy Return on Energy Investment, can measure the bio-physical properties of a resources progression over time There has been sporadicand disparate use of net energy statistics over the past several decades Some anal-yses are inclusive in treatment of inputs and outputs while others are very narrow,leading to difficulty of accurate comparisons in policy discussions This chapterattempts to place these analyses in a common framework that includes both energyand non-energy inputs, environmental externalities, and non-energy co-products
We also assess how Liebig’s Law of the minimum may require energy analysts toutilize multi-criteria analysis techniques when energy may not be the sole limitingvariable
Keywords Net energy · EROI · EROEI · liebig’s law · ethanol · biophysicaleconomics· oil · natural gas
12.1 Introduction
Human energy use, ostensibly the most important driver underpinning modern ciety, may soon undergo a major transition of both kind and scale Though numer-ous energy technologies are touted as alternative supplies to fossil fuels, scientistsand policymakers continue to lack a meaningful and systematic framework able toholistically compare disparate energy harvesting technologies Net energy analysisattempts to base decisions largely on physical principles, thus looking a step ahead
Green Mountain College, Poultney VT, USA
D Pimentel (ed.), Biofuels, Solar and Wind as Renewable Energy Systems,
C
Springer Science+Business Media B.V 2008
295
Trang 9296 N.J Hagens, K Mulder
of political and/or market based signals distorted by fiat monetary data The portance of net energy has been overlooked, primarily as a result of confusing andconflicting results in energy literature In this chapter, we (a) provide an introduction
im-to the hisim-tory, scale and scope of human energy use (b) reiterate the role of netenergy analysis in a world of finite resources, (c) establish a two dimensional netenergy framework synthesizing existing literature and (d) illustrate (via the example
of corn ethanol) why multi-criteria analysis is important when energy is not the onlylimiting variable
12.2 Net Energy Analysis
Energy, along with water and air, completes the trifecta of life’s most basic needs.Organisms on the planet have a long history of successfully obtaining and usingenergy, mostly represented as food Indeed, some have suggested that the har-ness of maximum power by both organisms and ecosystems from their environ-ments is so ubiquitous it should be considered the Fourth Law of Thermodynamics(Odum 1995) Cheetahs, to use one example, that repeatedly expend more energychasing a gazelle than they receive from eating it will not incrementally survive toproduce offspring Each iteration of their hunting is a behavior optimized to gainthe most energy (calories in) for the least physical effort (calories out), thus freeing
up more energy for growth, maintenance, mating and raising offspring Over tionary time, natural selection has optimized the most efficient methods for energycapture, transformation, and consumption (Lotka 1922) This concept in optimal
evolu-foraging analysis extrapolates to the human sphere via net energy analysis, which
seeks to compare the amount of energy delivered to society by a technology to thetotal energy required to transform that energy to a socially useful form Biophysicalminded analysts prefer net energy analysis to standard economic analysis when as-sessing energy options because it incorporates a progression of the physical scarcity
of an energy resource, and therefore is more immune to the signals given by marketimperfections Most importantly, because goods and services are produced from theconversion of energy into utility, surplus net energy is a measure of the potential toperform useful work for social/economic systems
12.3 An Introduction to EROI – Energy Return on Investment
Knowing the importance of energy in our lives, how do we compare different ergy options? Unfortunately, the word ‘renewable’ does not automatically connote
en-‘equality’ or ‘viability’ when considering alternatives to fossil fuels In assessingpossible replacements for fossil fuels, each alternative presents special trade-offsbetween energy quantity, energy quality, and other inputs and impacts such as land,water, labor, and environmental health (Pimentel et al 2002, Hill et al 2006) Whenfaced with these choices, energy policymakers in business and government will
Trang 1012 A Framework for Energy Alternatives 297require a comprehensive and consistent framework for accurately comparing allaspects of an alternative fuel.
Many criteria have historically been used to assess energy production nologies based on both absolute and relative yields and various costs (Hanegraaf
tech-et al 1998) Many assess economic flows (e.g Bender 1999, Kaylen 2005) whileothers focus on energy (e.g Ulgiati 2001, Kallivroussis et al 2002, Cleveland 2005,Farrell et al 2006) or emissions (e.g EPA 2002) With the recent acceptance ofglobal climate change as a problem, energy analyses favoring low greenhouse gasemissions are becoming more frequent (Kim and Dale 2005, Chui et al 2006).Though not yet widely accepted by market metrics, some other analyses haveattempted to include environmental and social inputs as well as energy costs.(e.g Giampietro et al 1997, Hanegraaf et al 1998, Pimental and Patzek 2005,Reijnders 2006)
The objective of an energy technology is to procure energy A common sure combining the strength/quality of the resource with its procurement costs isthe ratio of energy produced to energy consumed for a specific technology/source.This concept has many labels in energy literature including the energy profit ratio(Hall et al 1986), net energy (Odum 1973), energy gain (Tainter 2003), and energypayback (Keoleian 1998) In this chapter, we focus on Energy Return on Investment(EROI) (Hall et al 1986, Cleveland 1992, Gingerich and Hendrickson 1993) EROI
mea-is a ratio and mea-is equal to ‘net energy+1’ Total energy surplus is EROI times thesize of the energy investment, minus the investment We will use the terms energygain, net energy and EROI interchangeably, throughout this chapter
12.4 Humans and Energy Gain
Ancestral humans first major energy transformation came from the harnessing offire, which provided significant changes to daily tribal life by providing light,warmth and eventually the ability to work metals, bake ceramics, and produce tools.(Cleveland 2007) More recently, the energy gain of agriculture further transformedhuman culture Though the per unit energy gain of widespread agriculture was actu-ally lower than many hunting and gathering practices, a large amount of previouslyunused land was brought under cultivation, thus freeing up substantially larger en-ergy surplus for society as a whole (Smil 1991) This is a first example of how anenergy return combines with scale to determine an overall energy gain for society.Much more recently, the development of the steam engine catapulted mankind intothe fossil fuel era by leveraging the embodied energy in coal deposits The highenergy gain of coal rippled its way through the economy akin to a deposit in afractional banking system, and the industrial revolution had its first power source
In the 19th century, modern humans learned to unlock the hydrocarbon bonds in thehigher quality fossil fuels of crude oil and natural gas, freeing up orders of magni-tude more energy than our evolutionary forbears even dreamed about The changingsize of this subsidy, how to measure it and meaningfully compare it to potential
Trang 11298 N.J Hagens, K Mulder
Fig 12.1 Composition of US energy by (Cleveland 2007)
energy substitutes that will be required to power future society is the subject of thischapter (Fig 12.1)
12.5 Current Energy Gain
The current scale of our energy gain is unprecedented When coal, oil and ral gas are included, the average American uses 57 barrel of oil equivalents peryear (BP 2005) Each barrel of oil contains 6.1178632× 10ˆ9 Joules of energy Anaverage man would need to work about 2.5 years to generate this amount of heatwork1 Multiply it by 57, and the average American uses a fossil fuel subsidy equal
natu-to over 150 annual energy slaves But the quality of oil is also fantastic – liquid atroom temperature and highly dense – oil possesses energy quality that human laborcannot
An important nuance underlying the concept of net energy analysis, is that fossilfuel production is itself cannibalistic, as oil production uses a great deal of naturalgas (and some oil) to procure Coal production, wind turbine creation, solar photo-voltaic panels, etc all require liquid transportation fuels to generate their products
1 An ‘average’ worker utilizes 300 calories per hour At 8 hours per day, 5 days per week and 50 weeks per year this is 600,000 calories per year (6.1178632 × 10ˆ9 Joule) per barrel / (600,000
Calories× 4,184 joules required work energy per year) = 2.44 years/barrel.
Trang 1212 A Framework for Energy Alternatives 299
in a modern economy In fact, over 90% of world transportation is accomplishedusing liquid fuels (Skrebowski 2006)
The scale of remaining recoverable crude oil is a topic under much debate, withmany analysts saying we are already past peak production (Deffeyes), and others(IEA, Cambridge Energy Research Associates) saying we will reach a broad plateau
by 2030–2040 A large number of analysts believe a peak in oil production willoccur sometime in the next decade However, few if any of these analysts look athow much of future oil and gas production nets down to the societal use phase afterthe energy costs have been accounted for Nor is there a distinction made in ‘crudeoil’ statistics between actual crude oil, ethanol, coal-to-liquids, etc all of which notonly have disparate energy costs, but different BTU contents as well
The Hubbert curve of resource extraction is roughly Gaussian in shape, andthe energy surplus (or lack thereof) drops down dramatically after its peak (seeHall et al., 1986 for an example on Louisiana) If oil is peaking soon, asking howmuch is still in the ground is not the most important question How much can bebrought to market at one time? How much energy is left after energy companies usewhat they require internally to procure the harder to find, deeper, more sulfurous,more environmentally and socially sensitive drilling locations, etc.? These questionsultimately address how much of our remaining fossil resources will be available fornon-energy, non-government society
12.6 An Energy Theory of Value
There is a rich history over many decades of the concept of an energy theory ofvalue, dating back to Howard Scott and the Technocrats who stated that ‘A dollarmay be worth – in buying power – so much today and more or less tomorrow,but a unit of heat is the same in 1900, 1929,1933 or 2000’ (Berndt 1983) In the1970s, Senator Mark Hatfield argued that ‘Energy is the currency around which
we should be basing our economic forecasts, not money supply.’ His efforts sulted in the passing of (now defunct) Public Law 93.577 which stipulated that allprospective energy supply technologies considered for commercial application must
re-be assessed and evaluated in terms of their ‘potential for production of net energy’.(Spreng 1988) And in a still broader sense, ecological analysts have long stated thatmoney does not properly account for externalities – ecologist Howard Odum stated
‘Money is inadequate as a measure of value, since much of the valuable work uponwhich the biosphere depends is done by ecological systems, atmospheric systems,and geologic systems.’
12.7 Why is Net Energy Important?
This ‘work’ Professor Odum alluded to requires an energy surplus (Odum 1994) In
a world where energy is likely to become scarcer, net energy analysis is more ward looking than conventional economic analysis, and as such can be an important