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    <title><![CDATA[Discussion on What EROI tells us about ROI ]]></title>
    <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306]]></link>
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    <lastBuildDate>2013-06-19T09:20:11-07:00</lastBuildDate>
             

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        <title><![CDATA[What about EROI from household wastes]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-92565]]></link>
        <description><![CDATA[Wonderful article. However, I have a querry. Is there any academic inquiry carried out on the EROI and ROI on energy from wastes?]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-92565]]></guid>
        <dc:creator><![CDATA[Rhama Parthasarathy]]></dc:creator>
        <pubDate>Tue, 05 Feb 2013 00:37:52 -0800</pubDate>
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        <title><![CDATA[EROI]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-70685]]></link>
        <description><![CDATA[I was wondering why the handy chart mentioned in the article does not include geothermal]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-70685]]></guid>
        <dc:creator><![CDATA[rlmcbc]]></dc:creator>
        <pubDate>Mon, 14 May 2012 06:51:32 -0700</pubDate>
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        <title><![CDATA[Biased numbers]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-65561]]></link>
        <description><![CDATA[Your ERoEI chart appears to be ah, slightly biased:http://en.wikipedia.org/wiki/Energy_returned_on_energy_invested]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-65561]]></guid>
        <dc:creator><![CDATA[russtf]]></dc:creator>
        <pubDate>Sat, 10 Mar 2012 14:38:02 -0800</pubDate>
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        <title><![CDATA[You still need to trace through the energy]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64418]]></link>
        <description><![CDATA[Distillers' grain may still contain enough calories to be usable as feed, but it definitely will not contain as much as the raw corn (the energy in the ethanol has to come from somewhere).You are right that it should be factored into the EROI of corn ethanol, but you would have to think a bit about how you would measure that. One way might be in terms of calories of meat produced divided by calories of grain fed (which is, AFAIK, pretty terrible -- something in the region of 0.08 for beef). If you use that calculation, it barely changes the overall EROI of the ethanol.Of course this raises a whole separate issue -- that most of the US-produced corn not going into ethanol goes into meat production, which is a terribly inefficient way to feed people. But one thing at a time...]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64418]]></guid>
        <dc:creator><![CDATA[oneillkza]]></dc:creator>
        <pubDate>Wed, 22 Feb 2012 14:03:40 -0800</pubDate>
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        <title><![CDATA[It seems as if we might be better off...]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64387]]></link>
        <description><![CDATA[...using oil for things that do not require the oil distillate to be carried from place to place. Our vehicles carry both gasoline and a heat engine, neither of which is particularly light and for safety we place ALL these things as well as ourselves inside a steel body when the goal was to simply be somewhere else only to turn around and go home again.This is crazier then growing a lawn that you have to mow to enjoy.]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64387]]></guid>
        <dc:creator><![CDATA[ShockMe]]></dc:creator>
        <pubDate>Wed, 22 Feb 2012 06:49:23 -0800</pubDate>
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        <title><![CDATA[Boundaries of analysis]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64383]]></link>
        <description><![CDATA[Defining the boundaries of EROI analysis is difficult: how far back do you go when adding up the energy required to produce a form of energy? You can easily end up with a deep regression, making analysis impossible. Likewise the time of use issue. Dave raises some important points here, although staffing a planning office, for example, falls outside the typical boundaries. The authors of EROI research papers are usually careful to identify their boundaries of analysis, and readers should note those parameters carefully.]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64383]]></guid>
        <dc:creator><![CDATA[Chris Nelder]]></dc:creator>
        <pubDate>Tue, 21 Feb 2012 21:49:41 -0800</pubDate>
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        <title><![CDATA[That's not EROI]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64394]]></link>
        <description><![CDATA[EROI is typically measured at the wellhead, mine mouth, or other point of production. Net energy at the point of use--like in a car--is a whole 'nother topic.]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64394]]></guid>
        <dc:creator><![CDATA[Chris Nelder]]></dc:creator>
        <pubDate>Tue, 21 Feb 2012 21:41:40 -0800</pubDate>
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        <title><![CDATA[Good info on Nuclear Reactor Start]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64294]]></link>
        <description><![CDATA[That is good information about the lengthy time from proposal to building the reactor.  You should also include the decommisioning costs as well as the decades it takes to break down the reactor infrastructures.  The start up costs and the decommisioning costs pretty much wipes out the cost effectiveness of nuclear power.  It is a shame that nuclear power never lived up to the hype &quot;Too cheap to meter&quot; that was part of the sales appeal of nuclear power.Nuclear power will probably be in the mix for future energy needs.  There are other types of reactors being considered, perhaps one of these would be cost efficient.]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64294]]></guid>
        <dc:creator><![CDATA[sboverie]]></dc:creator>
        <pubDate>Mon, 20 Feb 2012 13:04:57 -0800</pubDate>
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        <title><![CDATA[Even now not all electricity is fossil fueled.]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64268]]></link>
        <description><![CDATA[Electric cars run on whatever source of electricity they use.  Here is the Pacific Northwest where I live we get a significant amount from hydroelectric and some from wind.  Even if it is fossil fuel powered electricity it is probably more efficient than the approximately 20% efficiency of an internal combution engine.  If some of the battery technology that's being developed comes to fruit batteries and hybrids won't be an issue.]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64268]]></guid>
        <dc:creator><![CDATA[riverat1]]></dc:creator>
        <pubDate>Mon, 20 Feb 2012 10:16:58 -0800</pubDate>
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        <title><![CDATA[EROI isn't as important as the energy budget over time]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64210]]></link>
        <description><![CDATA[EROI being a single number derived from a lot of data, doesn't reflect everything you need to know about the energetics of a particular technology. One critical factor is time - not only how much energy needs to be spent, but also WHEN it has to be spent compared to when you get your Energy Return.Ten years or so before a nuclear plant is commissioned, you have to build a large office and fill it with planners, engineers, lawyers, etc, desks, computers, lights, air-conditioning, etc. Some years later when construction starts, you need to buy lots of concrete and steel (both energy-intensive materials), and the usual load of trucks and bulldozers and construction workers (with their cars). As construction gets more advanced, the need for copper, aluminium and a whole host of exotic materials comes to the fore.Meanwhile somebody has to be digging up uranium ore and processing it into fuel rods, and that means finding twice as much Zirconium as Uranium for the tubes, and removing the Hafnium contamination from it.Eventually you get your reactor running and it produces a lot of energy, but it will still takes X years to repay the energy used to build it, so some of that energy has been spent (10+X) years before it gets repaid. Only then does the nuclear plant turn into an energy-positive project.But in the meantime, you have had to make a start on several other nukes, and they will still be in their energy-negative phase, so the industry as a whole is still energy-negative. And if you go on building more new plants, as you would have to do to scale up, there is a danger that you will NEVER reach the industry-wide energy-positive stage, before the general lack of energy collapses the economy.This applies whatever the technology, but affects low EROI and &quot;long building phase&quot;  technologies most. More at www.peakoil.org.au/news/index.php?energy_profit.htm]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64210]]></guid>
        <dc:creator><![CDATA[DaveKimble]]></dc:creator>
        <pubDate>Sat, 18 Feb 2012 16:28:26 -0800</pubDate>
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        <title><![CDATA[solar and wind]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64197]]></link>
        <description><![CDATA[PV solar has a very poor EROI, the next worst after ethanol. This is due to the energy needed to refine the silicon to ultra-pure standards. The ultra-clean, air-conditioned factory that makes those panels has to be built first (with fossil fuels) and it will operate for maybe 30 years if you're lucky. So some of the Energy Input must wait for 30+ years to be repaid with Energy Output.Wind turbines in windy places do much better, but even then they have limited lives. A wind farm on Hawaii ran for 20 years and then needed a major refit, but they scrapped it and built another one instead. This sort of thing is only possible in an energy-plentiful economy. When we change to an energy-scarce economy, these projects will be un-doable.]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64197]]></guid>
        <dc:creator><![CDATA[DaveKimble]]></dc:creator>
        <pubDate>Sat, 18 Feb 2012 15:59:22 -0800</pubDate>
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        <title><![CDATA[elasticity]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64213]]></link>
        <description><![CDATA[That assumes that all driving is discretionary, when in fact it's not. People have to get to work, and if they live in the suburbs they are unlikely to be serviced by public transport, so driving is effectively compulsory.Commercial vehicles, likewise, cannot just choose to use a bit less, because the amount of transporting of goods is directly related to profit. If a business can't make a profit, it goes out of business, and THAT is where you will see the reduction in consumption coming from - mass lay-offs.During the price rises of early 2007 to mid-2008, the price of WTI Crude Oil rose 72%, and consumption remained flat (instead of growing at 1.6% like the previous 20 years). Not much price feedback there.]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64213]]></guid>
        <dc:creator><![CDATA[DaveKimble]]></dc:creator>
        <pubDate>Sat, 18 Feb 2012 15:43:50 -0800</pubDate>
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        <title><![CDATA[NOT quite so]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64209]]></link>
        <description><![CDATA[Electric cars don't run on electricity, they run on the fossil fuels that fired the electricity generating plants. There are the usual losses due to inefficiency in this process, plus the losses in transmission, plus the losses in charging the batteries, plus the losses in drawing energy from the batteries, plus the energy cost of lugging the batteries around. And to make things more ridiculous, to overcome the limited mileage of the batteries, hybrids have a gasoline motor and a gas tank to lug around as well !]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64209]]></guid>
        <dc:creator><![CDATA[DaveKimble]]></dc:creator>
        <pubDate>Sat, 18 Feb 2012 15:33:04 -0800</pubDate>
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        <title><![CDATA[Further clarification]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64208]]></link>
        <description><![CDATA[When a process produces more than one product which is valuable, it complicates the EROI maths, but it can be overcome. Essentially what you do is apportion the Energy Inputs to the various Energy Outputs (co-products) based on the proportions of energy the outputs contain. This is standard practice among EROI mathematicians.]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64208]]></guid>
        <dc:creator><![CDATA[DaveKimble]]></dc:creator>
        <pubDate>Sat, 18 Feb 2012 15:23:39 -0800</pubDate>
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        <title><![CDATA[The big picture]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64179]]></link>
        <description><![CDATA[It's true that producing solar and wind devices does require material and energy input that is currently largely supplied by fossil fuels but once they are in place, other than normal maintenance, they don't require additional fuel input to produce energy.  And potentially much the energy required for their production could be supplied by already built solar/wind.  I wonder how much the fact that solar and wind have zero fuel cost affects their EROI.]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64179]]></guid>
        <dc:creator><![CDATA[riverat1]]></dc:creator>
        <pubDate>Fri, 17 Feb 2012 13:53:03 -0800</pubDate>
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        <title><![CDATA[ERoEI plus]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64176]]></link>
        <description><![CDATA[I am not disputing the relationship of ERoEI to ROI.  What I question is its basic relevance in judging solar and wind devices. These devices are extensions of the fossil fuel supply system.  There is a vast infrastructure of mining, complex processing, massive machines, large manufacturing facilities, multiply means of transportation as well as the regular accounted ERoEI inputs.  The actual direct energy contribution of this infrastructure may by small but the devices do not get made without it.  How are they factored in?  This makes these devices questionably renewable, alternative, clean, green or even sustainable.                                                                                                                  See: A story in pictures and diagrams:From Machines making machines making machineshttp://sunweber.blogspot.com/2011/12/machines-making-machines-making.html]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64176]]></guid>
        <dc:creator><![CDATA[john Weber]]></dc:creator>
        <pubDate>Fri, 17 Feb 2012 13:08:27 -0800</pubDate>
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        <title><![CDATA[Would like to see that data]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64172]]></link>
        <description><![CDATA[Jeremy, I'd be very interested in seeing any data you may have on the EROI of oil shale. I am working through some of Brandt's papers. Please contact me through the contact form here http://www.smartplanet.com/search?q=chris+nelder]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64172]]></guid>
        <dc:creator><![CDATA[Chris Nelder]]></dc:creator>
        <pubDate>Fri, 17 Feb 2012 10:26:52 -0800</pubDate>
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        <title><![CDATA[EROI of oil shale]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64130]]></link>
        <description><![CDATA[I have not seen EROI reported for oil shale at 1, although I have discussed Adam Brandt's values for two type of oil shale system with him extensively. I would suggest that the uncertainty is far larger on the high end, given values reported by technology developers at annual oil shale symposia which I co-chair.  While these have not yet been as rigorously tested, they provide suggestions that the EROI could be substantially enhanced once real systems are working. If only the values reported by a select few researchers are to be allowed, then perhaps the cited range is adequate.  I will certainly be delving deeper into the literature, especially regarding the feasible EROI cutoff for the traditional fuels, as well as trying to understand the potential EROI for electric vehicles, which perhaps you have already commented upon.]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64130]]></guid>
        <dc:creator><![CDATA[JeremyBoak]]></dc:creator>
        <pubDate>Fri, 17 Feb 2012 06:55:37 -0800</pubDate>
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        <title><![CDATA[Not necessarily]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64124]]></link>
        <description><![CDATA[Possible, but I tend toward the &quot;narrow ledge&quot; view I've written about previously. We could teeter at the edge of an EROI of 10 for years, as emerging economies slowly outbid the OECD for free-market oil. But eventually--I can't say when--high prices brought on by EROIs below that threshold will kill their demand, too.]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64124]]></guid>
        <dc:creator><![CDATA[Chris Nelder]]></dc:creator>
        <pubDate>Thu, 16 Feb 2012 12:40:33 -0800</pubDate>
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        <title><![CDATA[Thanks for the Clarification]]></title>
        <link><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64097]]></link>
        <description><![CDATA[I knew that plastics are made from what was left over from distilling fuel out of crude but I didn't know that the other products came out of the precipitates.  The point I'm trying to make is that the same crude oil is used for more than just fuel and what effects the cost of oil effects all the products derived from crude oil.]]></description>
        <guid><![CDATA[http://www.smartplanet.com/forum/discussions/1-9306-64097]]></guid>
        <dc:creator><![CDATA[sboverie]]></dc:creator>
        <pubDate>Thu, 16 Feb 2012 12:10:05 -0800</pubDate>
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