tag:blogger.com,1999:blog-580682852993585427.post616891696061298972..comments2023-10-23T12:32:16.375-05:00Comments on Real Energy: EROEIChris Dudleyhttp://www.blogger.com/profile/14124764472206647347noreply@blogger.comBlogger18125tag:blogger.com,1999:blog-580682852993585427.post-29609257213962079252013-09-25T00:25:01.690-05:002013-09-25T00:25:01.690-05:00It great to read post like this which includes top...It great to read post like this which includes topic like EROEI, i.e. Energy returned on energy invested. EROEI is a measure of the feasibility of an energy source and so it should be useful for comparing different energy sources to try to pick which one to use.<br /><a href="http://www.sterling-energy.com/services/" rel="nofollow">Professional Power Project</a>Krista Hileshttp://www.sterling-energy.com/noreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-59306817697843457352011-10-02T15:43:30.504-05:002011-10-02T15:43:30.504-05:00Hi, I'm doing a research project on whether gr...Hi, I'm doing a research project on whether green technologies are actually green and I found your page content really interesting. Is there any way I could get information on EROEI numbers/the energy used to make the product as well? I have not seen any sites with information like this, but I'm not sure if this is credible or reliable information for my project (if you have some references, I would love to know)dragonpolaraxishttps://www.blogger.com/profile/13825798595279281449noreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-4620302329221119672009-12-18T13:39:45.985-05:002009-12-18T13:39:45.985-05:00Considering the low EROI of nuclear power it is al...Considering the low EROI of nuclear power it is already dead. Fast Breeders are nothing but a pipe dream.<br />Nuclear plants are too much of a risc considering that they can be rendered useless in a matter of seconds. (Japan has powered down a 8.7GW plant due to an Eartquake for over 2 years...) Thats wasted money and resources.<br /><br />Furthermore there are wind technologies with a C-factor of 5000-7000h/a and an EROIE of 375.<br /><br />Also we must consider adapting usage to production by automated load balancing. Peaks can be lowered by 20-30%.<br />Thats much more efficient than puffering electricity in any form.<br /><br />Here is what you are looking for:<br />http://www.kitegen.com/en/<br />http://bit.ly/dF0WK <br />http://bit.ly/13ir3n <br />http://bit.ly/8OPWFY <br />http://bit.ly/WnXMb <br />http://nextbigfuture.com/2009/04/1-mw-and-20-megawatt-kitegen-wind-power.html<br /><br />27MW are built in the province of Asti right now...should go to grid by end 09...producing power for 5cent or under 60€/MWh (lower than fossile..which is the obvious target.)<br /><br />Nuclear stays dirty no matter how you put it.<br /><br />Even in the US you are trying to catch up with Europe now...<br />http://www.makanipower.com/<br />http://www.ted.com/talks/saul_griffith_on_kites_as_the_future_of_renewable_energy.html<br /><br />In ship propulsion we have already won :)<br />www.skysails.infoheavyweatherhttps://www.blogger.com/profile/10834812282913122215noreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-80598707023081693522009-03-14T18:50:00.000-05:002009-03-14T18:50:00.000-05:00What is the EROEI for Solar Cells?What is the EROEI for Solar Cells?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-45330321717964186902008-11-08T08:45:00.000-05:002008-11-08T08:45:00.000-05:00All the arguments you apply to nuclear down rating...All the arguments you apply to nuclear down rating its ERoEI also apply to solar PV. <BR/><BR/>http://www.energybulletin.net/node/14849<BR/><BR/>And others I have seen peg the ERoEI of PV as 1, once you add back in the bits "conveniently" left out by the people doing the calcs.<BR/><BR/>HamishAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-59344201230455345362008-09-29T09:59:00.000-05:002008-09-29T09:59:00.000-05:00Your post is very similar to a project I am curren...Your post is very similar to a project I am currently doing. I would love to be able to site your World Nuclear Association information, but your link doesn't work at the moment. Could you possibly update this? It would be much appreciated!<BR/>Thank you!Sarahhttps://www.blogger.com/profile/12697351877388054330noreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-6561045596467163252008-06-10T11:25:00.000-05:002008-06-10T11:25:00.000-05:00Brad F: what's your point? There's not much to imp...Brad F: what's your point? There's not much to improve from 90%. Just can't go much higher. 100% is the theoretical maxiumum. Wind can improve relatively more. One caveat is due here as well. The average capacity factor for all electric generators in the US is less than 45%. Moreover, it is dynamic - it fluctuates during the day (diurnally) as well as over the year (seasonally).<BR/><BR/>What this means is that 90% capacity factor nukes isn't as useful as one might think, especially when you realize that flexible nuclear powerplants are commercially completely unproven. France, for example has had issues with large amounts of nuclear power on the grid, and is only able to do it because of shutting the plants down during weekends and because of flexible hydro-electric plants but also because of exporting significant amounts of nuclear power abroad to European countries. Of course, that has diminishing returns if all countries in Europe go mostly nuclear, same for the US case. Who's going to buy power from the US? Canada already has loads of nuclear plants. Mexico maybe, but it's not a lot compared to the US use. And the US has relatively less flexible hydro potential because of it's much higher electricity consumption. Well there's your problem!<BR/><BR/>What we really need is flexible load following powerplants. Correlation with the load is one of the best measures for this. Wind isn't too good, even high capacity factors are generally less than 20-30 percent correlated (or so, don't remember the exact figures and it depends on which grid). Solar thermal with heat storage, for example is really good in this respect, so there's a very high limit to how much of such plants can be put on the grid with only a modest backup needed for the occasional rainy day or week (literally).<BR/><BR/>Now, a nuke running at theoretical 100% capacity factor would have perhaps 45% correlation with the load. Reasonable, but not great. We'll end up building more natural gas capacity than nuclear capacity just to be able to follow the load.<BR/><BR/>On the topic of this post, nuclear ERoEI will suffer from tuned down capacity factors due to higher penetrations of baseload nuclear. The reason is fairly straightforward: lower capacity factor means less energy out, lowering ERoEI.<BR/><BR/>Vehicle-to-grid offers a lot of potential to solve these issues, both on the nuclear as well as on the renewables side.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-55977352371428998872008-05-19T21:56:00.000-05:002008-05-19T21:56:00.000-05:00Has anyone calculated the EROEI for candu or other...Has anyone calculated the EROEI for candu or other heavy water reactors that do not require any fuel enrichment?<BR/><BR/>Also, the melting point of uranium is not relevant, as reactor fuel is uranium dioxide. This is a refactory ceramic that melts at around 2800C, although the zirconium metal fuel rods will fail at a substantially lower temperature.C W Mageehttps://www.blogger.com/profile/09706100504739548720noreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-4802662929083419832008-05-04T00:59:00.000-05:002008-05-04T00:59:00.000-05:00"Now, these are all nameplate capacities and we do...<I>"Now, these are all nameplate capacities and we do need to look at the capacity factors which are 82% for nuclear power worldwide, about 35% for wind and about 20% for solar, so wind is ahead of solar by a factor of nine."</I><BR/><BR/>Cyril, Chris was comparing what *is* a measured capacity factor for nuclear plants and so a measured capacity for what wind power is providing today is appropriate. <BR/><BR/>If you want to discuss what *might be*, then I could point out that the US nuclear industry has achieved a 90% capacity factor for several years running, and the design capacity factor for new baseload nuclear plants is 90% or better.<BR/><BR/>I don't disagree that the capacity factor for wind is capable of rising, if most new wind turbines are installed in the best locations. But the capacity factor is still low, and there will still be (hopefully small numbers of) turbines installed for greenwashing purposes in visible, but non-ideal locations to bring down the average.<BR/><BR/>To reiterate, the comparison was for *what is*, not *what might be*.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-48630231400374676422008-04-28T09:53:00.000-05:002008-04-28T09:53:00.000-05:00Those low capacity factors include older, smaller ...Those low capacity factors include older, smaller windmills. The new larger ones are getting higher capacity factors. And since we're building new ones, mostly big ones, that seems like a better figure to use.<BR/><BR/>Also, with larger amounts of wind installed, the economics of wind and electric transmission favour better but remote wind locations over suboptimal locations that are closer to the grid.<BR/><BR/>Typical capacity factors of modern large ~2 MWe turbines in good to very good locations is about 30-40%. This already includes some downtime for maintenance.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-87441162325482476702008-04-17T07:58:00.000-05:002008-04-17T07:58:00.000-05:00Chris,You were careful with your capacity factor f...Chris,<BR/><BR/>You were careful with your capacity factor for nuclear, but the capacity factor for wind is a fair bit lower than 35%.<BR/><BR/>http://www.ieawind.org/AnnualReports_PDF/2006%20AR%20IEA%20Wind/ES.indd.pdf <BR/><BR/>The link shows wind capacity factors at a minimum of 22% to a max of 26.6% in 2005 and a minimum of 21.8% to a max of 26.2% in 2006 among IEA Wind countries, which account for 83% of installed capacity worldwide. The min/max ranges are due to the large amounts of capacity being installed in each year. Not all the new capacity is generating for the full year, so in the absence of specific connection dates an average of the 2 values seems appropriate, say 24%.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-19519297271291483782008-04-09T23:40:00.000-05:002008-04-09T23:40:00.000-05:00Brad,Sorry to take so long to respond. If we look...Brad,<BR/><BR/>Sorry to take so long to respond. <BR/><BR/>If we look at the thermal EROEI for a doubling on conversion efficeincy, then 1.5 reactor are providing power to enrich uranium for 58 reactors and we get EROEI(thermal)=56.5/1.5+1=39 or about twice 19 as you expect. What seems to be bothering you is the behavior of the EROEI(actual) which is 56.5*0.6/1.5+1=23.6 which is 3.6 times larger than 6.5.<BR/><BR/>The behavior that is bothering you goes away if thermal energy is converted to electricity perfectly. So, if we are 3.3 times more efficient the EROEI(thermal)=57.1/0.9+1=64 which is the same as EROEI(actual). And, in the case where the efficiency is so low that we need all the reactors to power the enrichment plant, we get identical results. We can't go any farther than these two extremes with this example. So, yes, in some sense, to get the actual result of the the effort, the electricity out to society, we need to apply the efficiency twice.<BR/><BR/>Now, your solution to this is to say forget the reactors and just look at electricity in and electricity out. But, that ignores that what is being produced is thermal energy. To see why this is important, supose we powered all of our electricity use with either solar PV or nuclear. Both are delivering electricity and both have actual EROEIs of 10. How much energy needs to be produced to keep each system going? For solar you need 10% more panels producing 10% more energy and for nuclear you need 3% more reactors producing 10% more energy. The amount of extra energy production is the same. Looked at the other way, if we use EROEI(thermal)=30 for nuclear and system life over energy payback time for solar=30, we only need to produce one third the energy to keep the solar powered system going as for the nuclear powered system. So, using EROEI(actual) helps us to put things on the same scale. It indicates how much more or less messing around we have to do with the different options. The electricity only sources can have a lower EROEI(actual) than the EROEI(thermal) of the other sources and still lead to less extra energy production to keep the whole show going.<BR/><BR/>But, I think that the EDOEE measure can be used also if the EROEI picture seems too mixed.Chris Dudleyhttps://www.blogger.com/profile/14124764472206647347noreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-16798306537961431572008-04-01T07:32:00.000-05:002008-04-01T07:32:00.000-05:00Chris, I'm afraid you've fallen into what seems li...Chris, I'm afraid you've fallen into what seems like a common trap. Your EROEI equation is correct as far as it goes, although I would expand it slightly so that (net energy out) = (Energy out) - (expended energy). This is the same equation, with the terms clarified. It gives numbers that are slightly different, but comparable to what you used.<BR/><BR/>I presume (and correct me if I'm wrong) you will agree with me that doubling the efficiency of a process should result in a doubling of the EROEI. For instance, doubling the conversion efficiency of a solar panel will result in a doubling of EROEI, all other things being equal. What happens to your EROEI(thermal) equation if, in your French nuclear example, we double the thermal efficiency of the 58 reactors? The Tricastin diffusion plant won't require any more electricity for enrichment, so the energy used is cut in half to 1.5 plants. With your math (56.5*.6)/1.5 = 22.6, which is a quadrupling of EROEI for a doubling of efficiency. This demonstrates that your attempt to account for the thermal efficiency has resulted in an equation that is not mathematically consistent with what we expect. There's a problem with it.<BR/><BR/>I do agree that the electrical output is the proper measure of (energy out) when looking at nuclear electricity generation; however you accounted for the energy input to the gaseous diffusion process incorrectly. The energy input is the electrical consumption of the diffusion plant, not the thermal output of the reactors. The only thing this approach neglects is the EROEI of the electricity source. If we have an electrical source with an EROEI of 50, then when the energy is used as an input to another process, its contribution is the electrical energy used, plus the 2% embodied energy required to generate it. This additional 2% does not dramatically change the result, which is also a relatively high EROEI.<BR/>A thought experiment to illustrate the point: If you change the boundary of the system from "France's nuclear plants", to "France's electrical system" which includes a fair amount of hydro, and the French declare that they are dedicating their hydro resources to uranium enrichment, then there is no thermal conversion efficiency to confuse the issue. The electrical output of all reactors is able to be used elsewhere, and we both agree that the electrical output is what counts.<BR/><BR/>More later. I have to get to work now.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-20313725615427357332008-02-24T21:37:00.000-05:002008-02-24T21:37:00.000-05:00Oh Chris but I do want the fuel to melt. In fact ...Oh Chris but I do want the fuel to melt. In fact a reactor with a molten core has many advantages. If you read my blog youo will know why!Charles Bartonhttps://www.blogger.com/profile/01125297013064527425noreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-44544589432163054792008-02-23T00:40:00.000-05:002008-02-23T00:40:00.000-05:00Charles,Thanks for your comment. If you look at t...Charles,<BR/><BR/>Thanks for your comment. If you look at the table, both centrifuge and diffusion enrichment are considered. The limit on thermal efficiency now in nuclear power stems from the need to protect the fuel. In a gas turbine, you need to protect the blades, but you can use more refractory material. In a reactor, you don't want the fuel to melt, and uranium has a melting point 450 C lower than iron. This limits delta T and thus the efficiency.<BR/><BR/>Breeder reactors are not legal in the US. A breeding program would rather obviously produce even more fission products than we already produce, and these are among the most dangerous portions of the nuclear waste since their corresponding natural isotopes are part of our biological makeup. A first step to solving our nuclear waste problem is to stop making it I think.Chris Dudleyhttps://www.blogger.com/profile/14124764472206647347noreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-29968187683794778122008-02-15T09:54:00.000-05:002008-02-15T09:54:00.000-05:00chris, you failed to consider the effect of centri...chris, you failed to consider the effect of centrifuge technology on reactor EROEI. Centrifuges are 50 times more efficient than gaseous diffusion enrichment. The fundamental flaw in your thinking is stems from your failure to understand than the efficiency of nuclear technology can be improved. Since United States plans to open its first centrifuge enrichment plant in 2010, and its current gaseous diffusion plant is only supplying one customer, you ought to to asses the impending transition on nuclear EROEI. Beyond that you ought to look at preposed new nuclear technologies. Since thermal efficiencies as high as >50% are possible with some proposed reactors and nuclear breeding also greatly adds to reactor fuel efficiency, future reactor technology could blow the top off the EROEI chart. Not only are new reactor designs far more efficient, they simly eliminate the supposed problem of nuclear waste.Charles Bartonhttps://www.blogger.com/profile/01125297013064527425noreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-87635430672264548822008-02-05T12:05:00.000-05:002008-02-05T12:05:00.000-05:00The EROEI for utitily scale solar thermal electric...The EROEI for utitily scale solar thermal electric plants looks pretty good:<BR/><BR/><A HREF="http://www.ases.org/divisions/electric/newsletters/2006-04.html#roi" REL="nofollow">http://www.ases.org/divisions/electric/newsletters/2006-04.html#roi</A><BR/><BR/>The concept of carbonROI is also used which may be relevant with respect to emissions impact.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-580682852993585427.post-43818626235854131592008-01-21T20:29:00.000-05:002008-01-21T20:29:00.000-05:00I am indebted to a commentator at theoildrum.com (...I am indebted to a commentator at theoildrum.com (Mcrab) for pointing out a calculational error in an earlier version of this entry.Chris Dudleyhttps://www.blogger.com/profile/14124764472206647347noreply@blogger.com