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Topic: EROEI

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	Reference.com/Encyclopedia/EROEI
		In physics and energy economics, EROEI (energy returned on energy invested), ERoEI, or EROI (energy returned on invested), is the ratio between the amount of energy expended to obtain a resource, compared with the amount of energy obtained from that resource.
		When the EROEI of a resource becomes equal to or lower than 1, that energy source becomes an energy sink and can no longer be used as a primary source of energy.
		Measuring the EROEI of a single physical process is unambiguous, but there is no agreed standard on which activites should be included in measuring the EROEI of an economic process.
	www.reference.com /browse/wiki/EROEI (939 words)

	Getting a decent return on your energy investment \| EnergyBulletin.net \| Peak Oil News Clearinghouse
		EROEI turns out to be one of the most important measurements in the history of humanity.
		The EROEI for oil from the 1950s, when it was very easy to find, pump and refine, was as high as 100:1.
		For better and for worse, the EROEI for fuels in the future will not be as high as it has been in the past.
	www.energybulletin.net /14745.html (1334 words)

	Playahata.com - Game Over: The Industrial Devolution June 20th, 2004
		EROEI is basically how much energy one has to expend in order to obtain a given energy resource.
		Natural Gas has an EROEI in most cases(6.9-10.3) comparable to oil, burns cleaner than oil, and most automobiles can be converted to run on it.
		Solar has an EROEI of less than 1 using today’s technologies and there is little infrastructure to support it on wide scale, as inadequate investment has been made into research and development for a number of decades.
	www.playahata.com /pages/eyecalone/gameover_appendix (1160 words)

	Peak Oil News & Message Boards Forums >> Post 43149 >> EROEI: Energy Returned on Energy Invested
		EROEI is also an essential consideration in the substitution of one energy resource for another.
		An EROEI of 1 means that for every unit of energy you put in, you take 1 unit of usable energy out.
		EROEI (Energy Return on Energy Invested) means that the accounting is done in energy units.
	www.peakoil.com /post43149.html (2081 words)

	Alternate energy - a feasible replacement?
		The EROEI is calculated by taking the energy content of your energy (in whatever units you wish) and subtracting the energy used in producing the energy.
		The only time when negative EROEI can be worthwhile is if the energy produced is in a more useful form than the energy used.
		But negative EROEI is only acceptable if you have ample supplies of the one form and it looks likely in the future that we will be struggling for all.
	wolf.readinglitho.co.uk /mainpages/altenergy.html (1019 words)

	A Theory of Power, Jeff Vail's Critique of Hierarchy & Empire
		Although the EROEI of oil and coal have been dropping for decades so there must be enough fat in the system to absorb a lot of pressure too.
		That's the strength of the price-estimated EROEI approach, is that it most accurately accounts for the portion of energy embodied in each machine that should be attributed to each portion of PV.
		And if the EROEI of PV is less than 1:1 (which I argue it is, even though, as stated above, it is possible to have a solar EROEI greater than 1 within the Earth-system due to external energy inputs) then it is not free of environmental costs.
	www.jeffvail.net /2006/11/energy-payback-from-photovoltaics.html (8032 words)

	The Oil Drum \| A Net Energy Parable: Why is ERoEI Important? (Site not responding. Last check: 2007-10-13)
		EROEI analysis assumes an energy input which is considered a "gift", and and output of "useful" energy.
		Nevertheless, EROEI is probably still a useful concept when dealing with renewable energy "gifts" (the solar energy flux), and the inputs are fossil fuels, which need to be minimized for a number of reasons.
		The physics of eroei are easily understood and it is nice to see the primer, but you must use the full equation, all of the factors.
	www.theoildrum.com /story/2006/8/2/114144/2387 (14781 words)

	EnergyPulse Article
		I think your comment about EROEI stems from the in precision in our common usage of the word "energy." There is some physical insight gained by rating energy forms in terms of "energy quality" but even then, we don't have an air-tight methodology.
		EROEI is particularly good at spotting perpetual motion proposals early on as well as hidden subsidies.
		While EROEI has merit in our analysis of energy sources and markets, I will grant that valuatiion in stable currency is the only method that can provide a relative human valuation across energy sources, processing technologies, human needs, and final consumption.
	www.energypulse.net /centers/article/article_print.cfm?a_id=1115 (4494 words)

	Alternative energy: evaluating our options \| EnergyBulletin.net \| Peak Oil News Clearinghouse
		For example: an EROEI of 1 means that for every unit of energy consumed in the production process, we get 1 unit of energy to use for the next cycle of energy production.
		If the EROEI of any energy resource is less than 1, then doing that activity no longer adds to our energy stockpile.
		The concept of EROEI is usually ignored by politicians, disputed by alternative energy advocates, and distrusted by "Peak Oil" critics.
	www.energybulletin.net /14120.html (3040 words)

	Peak Oil News & Message Boards Forums >> Post 43170 >> Re: EROEI: Energy Returned on Energy Invested (Site not responding. Last check: 2007-10-13)
		When the EROEI ratio for oil exploration declines to the point that it merely breaks even--that is, when the energy equivalent of a barrel of oil must be invested in order to obtain a barrel of oil--the exercise will become almost pointless, regardless of any economic consideration.
		An EROEI of greater than 1 means you take more energy out than you put in.
		The main difficulty in having lower EROEI is that the technology is less nimble.
	www.peakoil.com /post43170.html (2082 words)

	The Hindu Business Line : Oil: On the skids
		By way of illustration, let us take an energy source which has an EROEI of 1 — which means that for every unit of energy spent, you get back one unit of usable energy.
		When the EROEI exceeds one, you are actually burning up more energy than you are getting for use.
		Eventually, the oil EROEI just will not work out — which is when people will start looking to other sources of energy such as coal and tar sands.
	www.blonnet.com /2004/08/24/stories/2004082400091000.htm (911 words)

	R-Squared Energy Blog: Fan Mail – Part I (Site not responding. Last check: 2007-10-13)
		The EROEI is a multi-step calculation: The crude portion and the refining portion.
		Also, the stated EROEI numbers for ethanol all ignore secondary inputs: the construction of the ethanol plant, the construction of the tractors, etc. So, what we have here is an apples to apples comparison between ethanol and gasoline, and the EROEI for ethanol is far inferior.
		Not only is this not true, but the ultimate irony is that due to the poor EROEI of grain ethanol (which I was addressing in the essay to which he responded), all of those infrastructure costs of petroleum are embedded within the ethanol process anyway.
	i-r-squared.blogspot.com /2006/10/fan-mail-part-i.html (4066 words)

	energy economics - extraction efficiency and costs, depletion of fossil fuels
		When an energy source that has an EROEI ratio of 4:1 is replaced with another, alternative, energy source which has an EROEI ratio of 2:1, twice as much gross energy has to be produced in order to reap the same net quantity of resulting usable energy.
		Consider that I inherited one barrel of oil, and the EROEI was 4:1.
		Remember that the EROEI for coal is, in general, lower than that for oil.
	www.abelard.org /briefings/energy-economics.asp (2275 words)

	EconLog, Oil Shale, Arnold Kling: Library of Economics and Liberty
		If EROEI for nuclear is somewhere in the 30s to 50s - minus the 1.5 for extraction of shale oil - you get a net EROEI for shale oil equal to or better than today's cheap oil.
		The trouble with EROEI is that at a practical level, not all energy is equal.
		Charging and discharging a battery obviously has an EROEI of less than 1.0, but if the production costs of an electric car with similar range and performance to petrol models were to be brought down to the point where it could be sold for less than $20k, the market would be all over it.
	econlog.econlib.org /archives/2005/09/oil_shale.html (2074 words)

	Safe Haven \| Preservation of Capital \|
		ERoEI is a valid consideration when there are reasonable alternatives.
		If the ERoEI of nuclear is low - and that seems to be the case from everything I have seen - the ERoEI of nuclear that depends on sea-water uranium is not only low, it is less than 1.
		Second, because of the low ERoEI, if nuclear energy is going to have a significant impact we will need to build many, many new nuclear power plants in the years just ahead - more than I think we will, and perhaps more than is physically possible.
	www.safehaven.com /forums-1766.htm (1510 words)

	Clean Energy Protest March 27th Midday State Parliament : Melbourne Indymedia
		And keep in mind that if over the life of a solar panel its ERoEI has been determined at (say) 1.2, then it will return only a tiny bit more energy than was required to construct, deliver, install and decommision.
		EPR (energy Payback Ratio) is more commonly used than ERoEI --Ratio of energy produced by a power plant during its life-span divided by the energy required to build, maintain and fuel the power plant.
		How can they realistically assign an EPR or ERoEI to a technology that basically doesn't exist, that has been 30 years off for well, the last 30 years, and looks like it'll be 30 years off forever, remaining perpetually just out of reach.
	www.melbourne.indymedia.org /news/2004/03/65069_comment.php (1497 words)

	EROEI - Wikipedia, the free encyclopedia
		Further information might be found on the talk page or at requests for expansion.
		In terms of abundance of elements, hydrogen is by far the most common in the universe, but that doesn't mean that hydrogen in Jupiter's atmosphere is an energy resource for humanity.
		EROEI is slowly becoming recognized as the ratio which underlies the very possibility of maintaining a civilization or a life form.
	en.wikipedia.org /wiki/EROEI (1134 words)

	The Ergosphere: Payback time
		One of the major issues of energy policy is EROEI, Energy Return On Energy Invested.
		Greater levels of insulation may pay off faster if combined with a smaller, cheaper heating plant or other economies made possible by the reduced heating load, and tax deductibility of mortgage interest versus operating expenses also adds a bias towards insulation.
		On a straight EROEI basis, retrofits of foam insulation appear to be a very good investment.
	ergosphere.blogspot.com /2006/02/payback-time.html (1784 words)

	Wind Blog » Blog Archive » Energy Payback of Wind Turbines
		The low EROEI is largely because of the intensive use of fossil fuels in fertilizer to grow corn.
		It seems to me that the EROEI for consuming fossil fuels is going down.
		We have tapped the easy to access oil and natural gas, with a good EROEI, and are now moving on to the harder to access sources like tar sands, arctic, and deep offshore.
	www.biofuels.coop /windblog/?p=13 (605 words)

	Thesis #18: Peak Oil may lead to collapse. (The Anthropik Network)
		Petroleum once had an ERoEI near 100--for the energy equivalent of 1 barrel of oil, you could extract 100 barrels of oil.
		On the subject of ERoEI -- the above person was (perhaps unintentionally) making the point that oil is such a valuable resources, that even when it does not return energy on energy investment, energy should still be invested to extract it.
		At an EROEI of 1, oil ceases to be an energy source and simply another energy-expensive product we rip from the Earth.
	anthropik.com /2005/12/thesis-18-peak-oil-may-lead-to-collapse (16396 words)

	Bad Money Drives Out the Good Service (Site not responding. Last check: 2007-10-13)
		EROEI was so favorable that people came to take it for granted, as some sort of immutable law of nature.
		In this respect, EROEI is currently a negative number when it comes to the search for oil.
		A negative EROEI means that mankind is throwing "good" energy away to move "dirt" and, in the end, recover low-grade raw hydrocarbon material that requires even more energy to upgrade to some useable form.
	www.whiskeyandgunpowder.com /Archives/2005/20051208.html (3746 words)

	Is the world about to run out of oil?
		An EROEI of one means that for every unit of energy spent or invested, you get back one unit of usable energy.
		When the EROEI is negative, you are actually burning up more energy than you are getting for use.
		The US figures for EROEI for non-renewables are all "plus", while for renewables, these are less than one for ethanol, switch grass and wood and negative for bio-diesel.
	www.rediff.com /money/2006/sep/30oil.htm (1139 words)

	EROEI Link \| Post Carbon Institute
		EROEI refers to Energy Returned on Energy Invested.
		In the case of Peak Oil when EROEI is 1 for 1 it will no longer be economically viable to continue to use this resource as a form of energy.
		When the energy descent occurs the EROEI ratio will continue to decrease until it reaches one to one or less than one for one unit of energy expended.
	www.postcarbon.org /node/3021 (282 words)

	M of A - EROEI PR
		Of course, as it comes from the World NuclearAssociation, hardly a neutral party, I took it with a grain of salt and chose not to include it in my post.
		I think the PR agencies have figured out that the EROEI concept/meme is percolating outward to people in the investor class, to the intelligentsia in the managerial class, and even to the proles.
		EROEI meant, but I am half way through "The Long Emergency", it is mentioned in there and for the first time I link here thru Billmon into an energy thread.
	www.moonofalabama.org /2005/04/eroei_pr_1.html (4827 words)

	The Cost of Energy: Some thoughts on EROEI and hydrogen
		One of the things we hear energy geeks flap their gums about endlessly online is the concept of EROEI (energy return on energy invested), a somewhat opaque term for a simple notion: In the long run you can't expend more energy to obtain an energy source than that energy source contains.
		In fact, the energy payback period is much shorter than the financial payback period, as the initial cost of a turbine has to be amortized over 15 or 20 years to yield a decent cost/kilowatt hour figure.
		All the processing of materials, bending and printing of the metal jacket, packaging, shipping of the batteries to the store, etc. are surely many times greater than the wisp of energy they produce.
	www.grinzo.com /energy/blog_entry_archive/2006/03/2006x03x13_2.html (1103 words)

	Cascadia Scorecard Weblog: Everybody Loves Biofuels
		With these caveats, my opinion is that the EROEI of cellulose ethanol is positive enough for it to be worth doing, or at least taking a very serious look at.
		In other words, Pimentel's EROEI figure could be close to the mark for the specific land that would go out of production if ethanol subsidies ceased.
		Your EROEI math was fine, by the way, there is no set way of doing it.
	cascadiascorecard.typepad.com /blog/2005/03/everybody_loves.html (3306 words)

	Response to Cobb's article
		Strictly speaking "net energy" is the difference between the energy input into a system (for example, an energy producing project like a power station and all the associated resources and infrastructure) and the energy output by the system over its lifetime.
		An ERoEI for an energy project is 1.00 when the process is at the break-even point, that corresponds to the net energy being zero.
		Nevertheless, such processes with ERoEI of much less than 1 can be worthwhile conversions, if the output energy form is more useful than the input energy form.
	home.austarnet.com.au /davekimble/cobb.reply.htm (1615 words)

	The Oil Drum \| Coal rank and thoughts on EROEI
		Often when we talk about different fuels, the fuel itself is considered to be something that can easily be defined.
		For those who wonder what is going on, this is a weekend tech talk, where some underlying aspect of fossil fuel energy is discussed.
		EROEI goes down as the interparticle bonding strength increases.
	www.theoildrum.com /story/2006/2/6/0505/48673 (4291 words)

	AN ACT ESTABLISHING THE RENEWABLE ENERGY DEVELOPMENT INSTITUTION.
		The institution shall consider the reasonable potential to achieve an EROEI of at least one in considering replacement values; (2) second priority shall be given to projects, technologies, equipment and other items that replace or conserve depletable fuels or energy.
		The reasonable potential to achieve an EROEI of at least one shall be the greatest factor in determining funding priority within this category of projects while reductions in pollution and global warming gasses shall be the second greatest factor in determining funding priority for projects in this category.
		“Depletable energy” is energy from nonrenewable resources and “EROEI “is the ratio of the amount of energy expended to obtain a resource to the amount of energy obtained from the resource.
	www.cga.ct.gov /2006/FC/2006HB-05728-R000467-FC.htm (1259 words)

	Oil stocks, anyone? - Page 2 - Jason Hommel's Silver Stock Report Forum
		The EROEI creep means that higher gross energy input with subsidies create an illusion of more available energy even if the net energy is not growing or downright diminishing.
		(4) The EROEI estimates for nuclear include bloated costs for the anti-nuclear regulatory climate in much of the world, lack of economy-of-scale in building reactors, excessive labor costs in 1st World due to debt bubble, emotionally wild overestimates of fuel storage costs, not amortizing build cost over the longer-life of newer plant designs, etc..
		The 100-to-1 EROEI stuff is long gone, the 10-to-1 stuff is peaking or fading, and so we are being enticed to invest into the 2 - 5-to-1 fossil stuff now.
	jasonhommelforum.com /forums/showthread.php?p=866 (4663 words)

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