Talk:Wind power

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To-do list for Wind power:

Incorporate recent pricing news from: Virginia, India/Singapore, Colorado, New York City, Canada, Cape Cod, Washington, D.C., General Electric, China, South Dakota, Pennsylvania, Texas, Europe
Check and polish prose
Move external links to "external links" section or (preferably) use footnotes
Add more images, especially of various types of wind turbines and wind farms. See commons:Category:Wind power and its subcategories.
- Note, there are a number of useful photos and artists conceptions of offshore windpower at http://ocsenergy.anl.gov/guide/wind/index.cfm This is U.S. federal government so all images are usable on Wikipedia.

Please consider added link to LIPA Wind Power Projects http://www.ieee.li/pdf/viewgraphs/wind_power.pdf

Archives

Archive 1	Archive 2	Archive 3
Archive 4

[edit] Environmental effects

"The initial carbon dioxide emissions "pay back" is within about 9 months of operation for off shore turbines.[86]" I don't think this sentence is supportable. There is one reference which refers to data given by one company for their turbines - hardly an unbiased source. Also, what about onshore turbines? Richerman (talk) 22:55, 3 November 2008 (UTC)

So which studies did you read that gave other numbers for CO2 payback? Put the references in the article! --Wtshymanski (talk) 23:07, 3 November 2008 (UTC)

I didn't say that I had, but I shall look around and see what I can find. This is a controversial subject and Wikipedia is supposed to be neutral, so I would suggest that the sentence should say something like "One company has claimed that the pay back for their off shore turbines is within about nine months of operation." Richerman (talk) 23:21, 3 November 2008 (UTC)

This article in a refereed journal gives an energy payback time of a modern 5 MW wind turbine for offshore use of only 4 months. However, I am not sure that the errection of the turbine is included. I don't have access to the full article unfortunately. Splette :) ^{How's my driving?} 02:06, 4 November 2008 (UTC)

Further, this PhD thesis from 2007 found an energy payback time of 0.39 years for an offshore wind park in Denmark. Splette :) ^{How's my driving?} 02:12, 4 November 2008 (UTC)

I've changed the wording a little and added some more references. The report to the UK House of Lords is interesting as it includes decommissioning and works out at 1.1 years. Richerman (talk) 10:21, 4 November 2008 (UTC)

Note that in addition to energy payback and CO2 payback there is a third issue of liquid fuels payback. At the moment, wind power generates electricity, whereas the trucks, trains, and ships that haul wind turbines, and the cranes that erect them on site, consume energy in the form of diesel fuel which comes almost entirely from petroleum. (Biodiesel offers the possibility of powering heavy mobile equipment in a more renewable way, but biodiesel will probably only be available in small quantities unless and until algae fuel technology advances substantially.) Thus wind power, at present, consumes a type of fossil fuel that it cannot yet pay back. Given that petroleum comes with supply risk (peak oil) and political risk (energy security), it would be nice to close the energy loop with wind turbines, so to speak, and come up with ways to supply more if not all of the energy to build wind turbines from wind turbines, or from sustainable biofuels. Currently we are not there yet: wind power by itself cannot build more wind power, and since we know petroleum is finite and unsustainable, wind power which depends on petroleum for its construction is also (at the moment) unsustainable. This is not an argument against wind power, of course, but if we can figure out how to build wind power using only wind power and other renewable sources such as biofuels, then the energy payback discussion could become much more direct. One might discover, for example, that to build a large wind turbine, one needs to run another wind turbine of the same size for one year. At the moment, almost every source of energy (including coal, nuclear, hydro, solar, and geothermal) depends on petroleum for liquid fuels it cannot yet repay. Thus (at the moment) one should not view these alternative energy sources as petroleum replacements, but rather as petroleum extenders or multipliers. If a wind turbine has an EROEI of 35, that's a pretty good petroleum multiplier, but wind power must eventually get completely away from reliance on petroleum or else wind power will stop shortly after petroleum does. Here is an interesting paper which discusses some ways to move toward that goal:

Bradley, David (2004-02-06). "A Great Potential: The Great Lakes as a Regional Renewable Energy Source". Retrieved on 2008-10-04.

including making renewable ammonia from wind-driven electrolysis of water (as Norsk Hydro did at its Vemork plant with hydroelectricity from 1911 to 1971), and using the reverse water gas shift reaction to create additional hydrocarbon fuels from wind-generated hydrogen combined with CO2 emissions from fermentation plants and wastewater treatment plants. --Teratornis (talk) 09:19, 5 November 2008 (UTC)

[edit] How wind farms work

One thing that seems to be missing from this article is a good explanation of how wind in converted into electricity. I think the design of a wind farm would probably make a good article in itself with a short section in this article pointing to the main article. There is an excellent collection of usable photographs www.geograph.org.uk here which shows all the stages of the construction of Scout Moor Wind Farm, with pictures of all of the components used, which would illustrate the article well. Richerman (talk) 13:04, 5 November 2008 (UTC)

A wind farm is just a collection of wind turbines - just what sort of explanation is appropriate? Do we need to descend to explaining blades and shafts and gears and wires whizzing through a magnetic field, or can we refer the curious reader to electrical generator and other such articles? Does anyone over the age of 9 need that explanation here? This could bulk up the article immensely and not convey much wind-farm-specific information at all. --Wtshymanski (talk) 15:46, 5 November 2008 (UTC)

Actually, forget what I said about a seperate article as I found the link to wind turbine after I posted this and it gives a lot of the information but some of it is quite technical and it doesn't actually say that much about what happens to the power that's produced. The main article wind farm does give more of what I was thinking of, so I think a few more lines in the section that's presently headed "Turbine placement" about how the electricity gets from the turbines to the national grid, would do it - although the heading would need to be changed. Richerman (talk) 17:21, 5 November 2008 (UTC)

See the links in the {{Electricity generation}} navigation template. They link to articles that describe how electricity grids operate. Some of those grid-related links are in the {{Wind power}} template which is already at the bottom of Wind power. These navigation templates function as a comprehensive introduction to a subject, by linking to a set of articles that describe many aspects of it, and how it fits with related subjects. In other words, to understand wind power in depth, you would need to read all the articles linked from {{Wind power}}. We make navigation templates so we don't have to repeat all the background information for a topic in every article related to the topic. One can, of course, find most of the same links scattered throughout the prose of an article. A navigation template collects them into one unified chunk, in case someone wanted to really get to know a subject by reading all of them. It might take a person several weeks to read all the wind power articles and have them sink in, because we have a lot of material on the subject. --Teratornis (talk) 17:55, 5 November 2008 (UTC)

Yes it would take a long time to read them all - that's exactly my point. Wikipedia articles are supposed to be accessable to the layman, so I was interested in improving this one by adding a couple of lines of explanation to make it more accessible. Anyone who wanted to go into the subject further could then follow the links. However, I can see I'm flogging a dead horse, so I've lost interest now. Richerman (talk) 22:48, 5 November 2008 (UTC)

See Wikipedia:Summary style. If you can find a way to work in a few explanatory sentences that summarize some related article, feel free. Wikipedia is supposed to be accessible to the layman, but that refers to reading Wikipedia. Editing Wikipedia, and having one's edits stick, is more difficult. Before making major additions or changes to an article, one should first read all the related articles to get the lay of the land first. That's not an argument against making changes, it's advice about how to make changes the smart way. Yes, it is a lot of work to learn enough about a subject and Wikipedia's coverage of it to be able to edit with a high chance of success here. The best articles are by people who have spent a lot of time studying Wikipedia. Nobody seems to know a shortcut method. By the way, I like the Scout Moor Wind Farm gallery you linked to above. We have some photo galleries on Commons, such as Commons:Wind farm and Commons:Wind turbine. You could make an account on Commons and add to those galleries, perhaps with a wind farm construction section or page somewhere. This is all a volunteer project, so nothing happens unless someone does it. Lately I've been working on a section Unconventional wind turbines#Wind turbines on public display which I might spin into its own article at some point, since there seems to be some wind turbine tourism springing up unexpectedly in various places around the world. It would be fun to feature some educational exhibits that exist at various wind farms, explaining how they work. --Teratornis (talk) 02:07, 6 November 2008 (UTC)

I should add, on a positive angle, that when one reads through all the related articles on a subject, one will likely see many ways to improve some of the articles, because some people who worked on some articles were not aware of all the related articles at the time. Either this was because some of them were casual editors who had not read all the related articles, or because some of the related articles were less complete or even nonexistent at the time. Wikipedia can benefit from editors who read lots of related articles and then see ways to improve articles in light of other articles that already exist. See Wikipedia:Build the web. My goal is to read every article on Wikipedia about the topic of energy, but since there are so many and they keep changing, that might not be a goal one could ever truly reach. --Teratornis (talk) 02:51, 6 November 2008 (UTC)

Well ,originally I thought someone who knew more about the subject would be better placed to make the addition but maybe I should have just been bold and had a go at it myself in the first place - I did actually write most of the Scout Moor Wind Farm article. Sometimes knowing a bit less about the subject makes it easier to make it more accessible to the others who are in a similar position. When I have some time I'll try adding something in, and if you don't like it you can always revert it :) Richerman (talk) 09:53, 6 November 2008 (UTC)

OK I've added that in now, but could someone please clarify the second paragraph under grid management system as it's pretty incomprehensible to the layman. For instance:

"Induction generators, often used for wind power projects, require reactive power for excitation" I've wikilinked "excitation" but couldn't this sentence be made clearer?
"Different types of wind turbine generators behave differently during transmission grid disturbances" What's a transmission grid disturbance - does this just mean a fault on the transmission grid, if so what sort of faults occur?
"induction generators cannot support the system voltage during faults" what does that mean?
"properly matched power factor correction capacitors along with electronic control of resonance can support induction generation without grid" what is resonance, and does this sentence mean that when there is nowhere to feed the electricity to the capacitors will deal with it?

I find the rest of the article quite comprehensible but this section is just too technical. Richerman (talk) 00:49, 8 November 2008 (UTC)

The first step in clarifying something on Wikipedia is to link all the jargon terms. At least then the reader might eventually get some understanding by drilling down through all the jargon definitions. AC power is pretty confusing, however, to anyone who hasn't taken at least an introductory course in Electrical engineering. I'm not sure how clear that section could become to someone who hasn't. I added a link to Induction generator. While I was there, I added the {{Electricity generation}} template to some of the jargon articles, and added links to the template. If you have questions about specific passages in an article, and you can't figure them out by the usual tricks of Googling and reading all the references and linked-to articles, you can ask the original author for clarification. You can find the original author by checking the history or using a tool like Wikiblame. It would be nice if everything on Wikipedia could be a masterpiece of clarity, but few articles start out that way. A sentence like "Different types of wind turbine generators behave differently during transmission grid disturbances" surely won't cut it in a featured article (it borders on weasel wording), so if you can figure out how to answer the questions you identified as following directly from the vague sentence, that would help a lot. One approach is to {{Google}} or {{Google wikipedia}} for phrases such as "transmission grid disturbances". The confusing paragraph does cite two sources, but does not link to online versions of the cited articles. I'm guessing the cited articles may explain the material in more detail, not that they would necessarily be understandable to non-engineers. If nothing else, we can be pretty confident that someone out there must know how to hook wind farms up to power grids, because there are lots of wind farms on power grids, so all this material must be written down somewhere, perhaps in an accessible format. --Teratornis (talk) 23:45, 8 November 2008 (UTC)

I added more links on jargon terms, perhaps making the passage almost understandable. (I said "almost".) I looked up proper citations for the two references with {{Google scholar cite}}:

Now at least the citations have links to the article abstracts. Only IEEE subscribers can view the articles online, and I'm not one. --Teratornis (talk) 00:34, 9 November 2008 (UTC)

Thanks for that - as you say it's "almost" understandable now. However, I've now had to edit the page on Low voltage ride through that you linked to - is there no end to this editing (sigh!!). And that one has the phrase "defined as the reactive current of the positive sequence of the fundamental" - ?? I have a mission to make as many articles in wikipedia as understandable as possible which, as you say, more often than not means looking up things yourself and taking a stab at rewording them. However it's usually best to try and get the people who understand the subject to do it first :) Richerman (talk) 01:09, 9 November 2008 (UTC)

There is an end to Wikipedia editing - when every article is a featured article, and all notable topics have articles. And, I suppose, nothing new occurs in the outside world for us to write about. WP:FA says:

At present, there are 2,300 featured articles, of a total of 2,616,426 pages on the English Wikipedia. Thus, about one in 1,130 articles is listed here.

That means we have a considerable distance to go. We are also getting farther behind each day, as the number of articles increases much faster than the number of featured articles. Only a tiny fraction of Wikipedia's users have read and understood enough of the friendly manuals to contribute featured-quality edits. I suspect that to really get a handle on the quality problem, Wikipedia will need much better editing tools. For example, currently the procedures for creating footnotes (in WP:FOOT, WP:CITE, and WP:CITET) are so tedious and bewildering that only a few users have mastered them. Plus there's the larger problem that most people aren't very good writers. We may need computers to pass the Turing test so they can "understand" what we are trying to write, and express it clearly for us - or, at least, the computer could identify all our ambiguities and pose questions to the human writer that would resolve them. This is how a skilled human writer collects information from other humans who don't communicate well, and cleans it up. Probably most of the energy articles on Wikipedia need work - most that I have looked at, anyway. See User:Teratornis/Energy for my notes about some of the articles I have worked on or thought about working on. You don't have to fix every problem on Wikipedia, but anything you can improve will help out. (Even just writing notes about the problems you see is better than ignoring them.) If enough people do that, eventually we could get there. I recommend trying to recruit people who have an interest in these subjects, but are currently wasting their energy by posting throwaway messages on discussion sites and so on. Online discussion fills a need, but it doesn't lead to an organized structure of knowledge like a wiki does. Posting on discussion sites is a lot easier than learning to build an encyclopedia, but if more people learn to do what we are doing here, collectively we can produce something of real value. Just adding links between articles helps a lot, because it brings more interested eyeballs to articles on obscure topics like Low voltage ride through that might otherwise languish. I would like every energy article to have some sort of navigation template, for example. That would reduce the tendency for these articles to get orphaned. --Teratornis (talk) 02:31, 9 November 2008 (UTC)

The phrase: "defined as the reactive current of the positive sequence of the fundamental" might refer to Fourier analysis or Harmonic analysis. It won't make sense to someone who hasn't studied the applied mathematics of Power engineering. It might be nice to add a bibliography to some of these articles with a note: "If you wanted to understand this article, you would first read all these engineering textbooks". We don't have to explain everything, but we should try to link to the explanations. Ultimately it would be nice if a person could learn any career just by reading Wikipedia, but that point is far off. --Teratornis (talk) 02:42, 9 November 2008 (UTC)

I searched with Google Books and found this textbook reference:

Akagi, H.; Edson Hirokazu Watanabe, Mauricio Aredes (2007). Instantaneous power theory and applications to power conditioning. IEEE Press Series of Power Engineering. John Wiley & Sons. p. 137. ISBN 9780470107614.

which looks suitable to cite for "the reactive current of the positive sequence of the fundamental". I'm adding it to Low voltage ride through. --Teratornis (talk) 03:13, 9 November 2008 (UTC)

Interested eyeballs? now there's a concept..... Actually the comment about editing was meant to be ironic :) I know I'm going to spend the rest of my life being a busybody on wikipedia and trying to improve things. I would like to pick you up on one point though - wikipedia is not a textbook and you shouldn't need any prior knowledge to understand an article. To quote from wp:what wikipedia is not:

A Wikipedia article should not be presented on the assumption that the reader is well versed in the topic's field. Introductory language in the lead and initial sections of the article should be written in plain terms and concepts that can be understood by any literate reader of Wikipedia without any knowledge in the given field before advancing to more detailed explanations of the topic. While wikilinks should be provided for advanced terms and concepts in that field, articles should be written on the assumption that the reader will not follow these links, instead attempting to infer their meaning from the text

The problem I find with many of the special interest wikiprojects, is that the articles get rated by people on the project who understand the subject and they forget that the articles should be accessible to everyone. It's only when they get put up for GA or FA review that the problems become apparent. If you think of a print encyclopaedia like the Encyclopeadia Britannica they were traditionally bought by people with families who wanted good comprehensive reference works for school projects so they were aimed at children between the ages of about 9-16, which is what we should be aiming for. Actually, I've been editing for just over a year now and I only discovered yesterday there's a gadget on "preferences" that makes adding citations a lot easier. Richerman (talk) 13:15, 9 November 2008 (UTC)

Emphasis on the phrase bought by. Wikipedia is a free encyclopedia. But there is a catch: Wikipedia is a do it yourself encyclopedia. Wikipedia doesn't pay its contributors; they write only for their own enjoyment. Wikipedia contributors write for themselves. Thus if someone finds something they don't like about Wikipedia, the response is WP:SOFIXIT - the burden of making Wikipedia understandable rests on the person who doesn't understand something. That is, in fact, a great strength of collaborative editing: nobody knows better than you do what you don't understand. So if something isn't clear, then clarify it. The first step is to look up all the jargon terms, and make sure they have links. Read all the linked-to articles, and then come back and try to clarify the jargon-laced confusion. If millions of people read Wikipedia, and each one clarifies just one sentence they initially found confusing, the result will be better than any one expert could have written. Yes, Wikipedia "should" be all sorts of wonderful things, in the ideal fantasy world where everyone is a world-class writer willing to slave endlessly at no pay on behalf of others, but in practice, Wikipedia is whatever its readers feel like making it, subject to all sorts of constraints, including self-interest and laziness. In its current implementation, Wikipedia promotes quick edits and tends to punish excessive effort. The more you change what is already there, the more likely other users are to change your work. Thus there is little incentive to invest great effort into editing material that any other user can simply delete. After watching chunks of one's work going poof, one tires of fighting to defend one's contributions, and instead looks for things to add that don't go poof as readily (such as navigation templates, actually a great tool for improving understandability and generally less likely to ignite edit wars). Traditional print encyclopedias also have it far easier in that they don't cover as many topics as Wikipedia does. I'm sure we can find some Britannica-sized subsets of Wikipedia that are as understandable to the layman as Britannica. But Britannica doesn't have anything like Wikipedia's depth of coverage on lots of complex scholarly or professional fields. Can we expect to make topics such as abstract algebra or tensor calculus understandable to children ages 9-16? Parts of Wikipedia compare to Britannica, while other parts compare to specialist encyclopedias such as the Kirk-Othmer Encyclopedia of Chemical Technology. Kirk-Othmer certainly doesn't target ages 9-16; it's a working tool for chemical engineers and industrial chemists. If we did a proper usability study on Wikipedia, we'd probably find that most readers don't get much beyond the lead sections of articles anyway, so if we can at least make the leads understandable, we may be satisfying 90% of the audience. Really, all Wikipedia asks of anyone is to leave things slightly better than you found them. Give us enough slight improvers, and we will move the Earth, like trillions of earthworms quietly reshaping the landscape, one little mouthful of dirt at a time. --Teratornis (talk) 07:32, 10 November 2008 (UTC)

Well, such a poetic note is probably a good place to end the discusion before we get told off for straying outside what should be discussed on the talk page for this article (mea culpa, mea maxima culpa!) One day we may change the world, but we've made a small start with this article - onward and upward!!! Richerman (talk) 11:02, 10 November 2008 (UTC)

Under "Please Fix", the relevant unit would be deaths per TWH, not deaths per TW. I believe the dwarfing will not be so marked. windaction dot ord has statistics on accidents and deaths, but not including deaths or severe injuries from manufacturing or transporting WT parts or assemblies, which are very relevant, given the comparative bulk and count of WT compared to coal facilities per lifetime TWH production. - Tom Stacy —Preceding unsigned comment added by Save Western Ohio (talk • contribs) 18:18, 13 November 2008 (UTC)

[edit] Intermittency

In the intro, the article currently says "The intermittency of wind seldom creates problems when using wind power to supply a low proportion of total demand. Where wind is to be used for a moderate fraction of demand, additional costs for compensation of intermittency are considered to be modest.". I have no doubt that some people hold that opinion (particularly the first sentence), but can it really be stated as fact? It smells a little of bias to me. Moreover, the citation given doesn't seem to strongly support the view, and says something along the lines of "studies are ongoing" and avoids any strong conclusions. TastyCakes (talk) 20:28, 17 November 2008 (UTC)

I think you're right - without reading the whole paper cited I searched for the word "intermittency" and only came up with one hit, and that's in the title of one of the references. So as the paper itself doesn't use the term I think, at best, the statement above would be synthesis. Richerman (talk) 23:34, 17 November 2008 (UTC)

Its not an opinion, it is the view of a large group of experts who have reviewed all the available evidence for the UK - and which is a far more problematic system than the US or Canada since it is much smaller. See the UKERC report.

http://www.ukerc.ac.uk/ImportedResources/PDF/06/0604_Intermittency_report_final.pdf

The wording is perfeclty adequate - it means "not worth worring about, not significant, not a big issue"Engineman (talk) 10:26, 20 November 2008 (UTC)

Yes it is a fact - just read the other references - from National Grid UK, to the IEA etc. Engineman (talk) 02:10, 18 November 2008 (UTC)

Which references specifically? If they do support it and it isn't disputed by other references of similar weight, why aren't they cited after the statement is made? I believe this statement should be removed from the introduction because even if it is true in Europe's case (which I am not convinced of) and even if everyone does agree with that (which I am even less convinced of) and even if it weren't a complete unquantified matter of opinion what is considered "seldom" or "modest" (which it is), I know for a fact that it is disputed in other parts of the world, like Alberta where the governing electric board has put caps on how much wind power can be created out of fear of it not being a stable enough source and leading to blackouts. TastyCakes (talk) 15:40, 18 November 2008 (UTC)

While I agree that the quote you object to in your first comment suffers from weasel words (what is the meaning of "low proportion", "moderate fraction", "seldom" and "modest"?), the example from Alberta does not strictly appear to contradict the claims, as the example does not appear to assert either of these things:

That the governing electric board's caps on wind power are substantially below the "moderate fraction of demand" (whatever that could be).
That the additional costs for compensation of intermittency in Alberta are "immodest".

You also did not state whether Alberta's caps are to be temporary or permanent. A temporary cap on construction of wind farms might be necessary in a particular region to allow associated infrastructure projects projects to catch up (larger transmission grids, Smart grid, SuperGrid, Grid energy storage, organizing Demand response strategies, etc.). For example, the Raccoon Mountain Pumped-Storage Plant took eight years to build. A facility of that size could buffer the intermittency from a lot of wind turbines on a daily or weekly basis, but would lack capacity to buffer a large seasonal variation in wind power. One has to read the rest of the Wind power article to get a more accurate view of the grid adaptations necessary to absorb large amounts of wind power. (The best video summary I have seen is The Combined Power Plant at YouTube, which outlines a strategy to supply 100% of electricity from renewables.) The intermittency problems are solvable, but you have to solve them. Electric boards that don't plan for wind could run into problems, just as they would run into problems if they installed large amounts of any particular generating technology without accounting for the particular nature of that technology. Every form of generating technology presents problems for grid management. Hydroelectric plants can have drastic seasonal variations in water flow, nuclear power plants do not follow variations in load and are subject to lengthy unscheduled outages, natural gas plants are subject to unpredictable fuel price spikes or outright shortages, etc. (When did anyone object to a hydroelectric dam project on the basis of its expected seasonal variation in output? Until recently I wasn't even aware that grid managers had been quietly handling this problem for more than a century.) We hear more objections to wind because the technology is new and grid managers are therefore not as knowledgeable about how to handle its particular mix of problems as they are with older technologies they understand better. For example, it's understood that when you build a nuclear power plant, you simultaneously build pumped storage or peaking power plants along with it, because nuclear power plants have little ability to vary their output, and thus they they cannot follow the more-than-factor-of-two daily variations in power demand. Since a nuclear plant takes about ten years to build, there is plenty of time to build the other stuff necessary to make nuclear power usable. Wind power has one of the fastest construction times of any type of utility-scale power. Normally this would be an advantage, except that it sometimes allows wind farms to get ahead of the rest of the grid, in terms of outrunning the available pumped hydro storage and so on. One way for Alberta to deal with its wind power intermittency might be to export most of its wind-generated electricity into the insatiable U.S. energy market, but this would require construction of additional HVDC interties. --Teratornis (talk) 22:57, 19 November 2008 (UTC)

I might add that wind turbine manufacturers currently have something like a five year order backlog (although this source seems to put Vestas' order book at just over one year, which may refer to committed orders or something - I gather that if you decided right now you wanted to build a brand new wind farm, you might have to wait five years to get your turbines, since so many projects are ahead of you in the pipe). If Alberta isn't ready to put up more wind turbines, plenty of other people will be happy to jump ahead of Alberta on the waiting lists. This would strongly suggest that there are more regions in the world where the existing or planned grids can handle more wind power than wind turbine manufacturers are able to satisfy right now. That is, the limiting factor in wind power growth right now is not impact on grids, but simply building the turbines. That could of course change in five or ten years if wind turbines begin to saturate the ability of grids to absorb their output, and if compensatory technology does not expand fast enough. But lots of people are talking about the compensatory technology too. --Teratornis (talk) 23:07, 19 November 2008 (UTC)

I might further add that if the worst-case scenario for wind power is the occasional blackout, that's a scenario shared by every other form of power generation and transmission. Blackouts have occurred since the invention of electricity generation, and will continue to occur; people have managed. The worst-case scenarios for coal and nuclear are considerably more daunting: runaway global warming (and ultimately, fuel depletion) for the former; catastrophic reactor breach and nuclear terrorism (and also, ultimately, fuel depletion) for the latter. --Teratornis (talk) 23:31, 19 November 2008 (UTC)

You are clearly more informed on this subject than me, so I'll leave what to do with that statement in the intro up to you and other similarly knowledgeable people. But it still reads like a blanket statement to me, over simplified if not non-neutral. You would seem to be right about Alberta, to my knowledge the cap hasn't been approached and it remains a hypothetical in practice. TastyCakes (talk) 15:21, 20 November 2008 (UTC)

The difference is that for wind, the loss of power is a routine event, while for coal and nuclear it's an extraordinary one. That Stanford study says that wind can't be counted on for more than 20% of nameplate capacity, even for a widely-dispersed set of wind farms.

Also, nuclear reactors are capable of load-following (cf. France and the US Navy), it's just that their marginal cost per kW-h is so cheap that they're about the last thing you'd cut back to match falling demand.

—WWoods (talk) 17:59, 20 November 2008 (UTC)

Responding to each point separately:

An outage that occurs on an average of once per year is little different than an outage that occurs once per week, from the standpoint of grid management. Either way, the grid must have enough backup power or demand-management capacity in place at all times to offset the expected loss of supply. If a nuclear plant goes down for two weeks for a scheduled refueling or an unscheduled repair, another generator unit of comparable size must be ready to step in, and that unit must be ready all year. Each type of generating technology has its own availability schedule. The standard tactic is to link multiple generating units together on a grid, to reduce the chance of too many units failing all at once.
The Stanford study result shows that interlinked wind farms are actually not much worse than hydroelectric power on the basis of capacity factor, and possibly better during some seasons. See the capacity factors in the table in Hydroelectricity#Countries with the most hydro-electric capacity. France's annual hydro capacity factor is as low as 25%. Individual hydroelectric plants may experience very large seasonal variations in output, producing very little output for months at a stretch. However, grid managers will accept these variations to gain the other advantages of hydro, such as its inherent storage capacity and dispatchability (a hydro plant can go from zero to full power in as little as one minute). Although the 20% "baseload" output of interlinked wind farms might sound bad, that's an artifact of the nameplate capacity of a single wind turbine. Getting full output from all the wind farms at once might be such a rare event that the total nameplate capacity is not a meaningful number. Grid planners might instead design for the output to float between, say, 20% and 40% most of the time. That's within the level of daily demand variation that grids already handle, although a bit more challenging because Wind power forecasting needs more development.
Wind power is also capable of following load (by feathering turbine blades to spill wind), but this is undesirable for the same reason that throttling back a nuclear plant is undesirable: because the marginal cost of the spilled electricity is so low. When a power source "wants" to run at whatever full output it is capable of at the time, that makes it a bit of a prima donna on the power grid, expecting other power sources to make even larger adjustments to accommodate swings in demand. Wind and nuclear are both prima donnas in this regard. Neither one is ideally suited to following the drastically changing real world electricity demand. In other words, baseload power is a kind of engineering fiction, a mental construct invented to reify the undesirable characteristics of large thermal power plants into something that is somehow desirable. However, the mismatch between nuclear power supply and electricity demand is straightforward to bridge with peaking power plants and grid energy storage. As far as I can recall, the Nuclear debate was never about whether we had to build Pumped-storage hydroelectricity to go along with the nuclear power plants. Having to build the storage or the peaking power was never an issue with nuclear, but for some reason it's made out to be an issue with wind.

Isn't nuclear more or less the opposite of wind in this manner, consistently providing a (usually) predictable amount of power? Why would it need pumped capacity rather than simply be used to provide the baseload? (unless your nuclear capacity is sometimes above your baseload and you want to keep the difference for use when usage peaks, of course) TastyCakes (talk) 17:07, 21 November 2008 (UTC)

My apologies to anyone who is tiring of this discussion, but it's a very important issue because wind power is certainly intermittent. The intermittency of wind might be its number one issue. There is certainly no issue with nuclear accidents or terrorism with wind. Dealing with intermittency is a complex topic and is very easy for people to distort with sound bites. Our job on Wikipedia is to find that neutral point of view somewhere in the middle. I tried to help by starting some navigation templates such as {{Wind power}} and {{Electricity generation}} which link to clusters of articles that describe all the relevant issues. Someone who only reads the Wind power article, for example, might not come away with an adequate understanding of wind power's relationship to the electric grid. They also need to read everything grid-related in {{Electricity generation}}. --Teratornis (talk) 01:25, 21 November 2008 (UTC)

To reply to the interleaved question: nuclear is more or less the opposite of wind in that it doesn't follow load either, but in a more predictable way most of the time. I'm not sure "Why would it need pumped capacity?" is the right question. The question is really: what is the cheapest way to deliver electricity to consumers who want more than twice as much of it at 3 PM than they want at 3 AM? Nuclear-generated electricity is sufficiently cheaper than gas turbine generated electricity that the difference will pay for a pumped storage plant if a suitable location is available (a steep bluff overlooking a lake, with room on top for a big reservoir). Interestingly, the pumped-storage plant is also cheaper than building the same extra capacity in a nuclear power plant that would be idle at night - nuclear power has capital costs that rule it out for peaking power. When someone proposes building a nuclear power plant, nobody argues against it on the basis that nuclear power doesn't follow the enormous daily and weekly swings in electricity demand. That's because everyone has accepted the engineering fiction of "baseload power." Somehow what is really a limitation of coal-fired and nuclear power plants, that they cannot economically adjust their output to fit transient variations in demand, has instead been spun into a desirable characteristic, or at least a non-problematic one, which then dictates how the rest of the grid must adapt around it. Dealing with the transient nature of wind power is harder than dealing with the inflexibility of baseload plants, but it's really only a harder version of the same problem of not matching the transient demand. It's not a different kind of problem which is somehow unique to wind and is going to exceed our engineering abilities. --Teratornis (talk) 10:16, 2 January 2009 (UTC)

I might add that wind turbines have low capacity factors for similar kinds of economic reasons. It's easy to get high capacity factors from wind turbines: just build them with big rotors and small generators, so they reach full output in a low wind speed. If wind speeds are higher than this low speed most of the time at a particular site, the wind turbine can have a high capacity factor. But the average cost of electricity will be higher because the wind turbine will spill most of the available wind energy when the wind blows harder. Thus a good portion of the variation in output from a wind farm comes from the owner's desire to optimize his own economics, i.e. to make more money when the wind is blowing hard, at the expense of whoever has to deal with the resulting variability down the line. In a perfect electricity market, spot pricing would spread the cost of wind variability correctly. The spot price of electricity would send the right signals to producers and consumers, for example rewarding consumers who have the flexibility to schedule their consumption to match high wind periods, and reducing the profit for generating lots of electricity when the wind is blowing hard over many wind farms across a whole region. Spot pricing might shift the economic optimum toward wind turbines with higher capacity factors (e.g., bigger rotors without a proportional increase in generator capacity), but the optimum would probably keep shifting as a function of changes in other generating plants on a grid. --Teratornis (talk) 10:30, 2 January 2009 (UTC)

[edit] more intermittency

Don;t know why people are still concerned about this as an issue - its a done deal. There is simply no evidence to show that intermittency iwth large or huge penetrations of wind, is going to be any more of a problem than it is with existing power stations which can and do stop suddenly unexpectedly. There are plenty of technologies to deal with it - at the very least you simply start the existing power stations which are kept in readiness. Czisch shows that even with 70% renewables costs can be comparable to present day costs. Face the facts - the future is large scale wind and inter connectors. sorry if this sounds arrogant but we have endlessly discussed the issues and covered how they are soluble. Lets move on. Intermittency of wind is no more of an issue for wind than it is for other forms of power generation and the INTERMITTENCY OF EXISTING LOADS. Engineman (talk) 08:09, 20 November 2008 (UTC)

From wikipedia "windpower"

Penetration

Wind energy "penetration" refers to the fraction of energy produced by wind compared with the total available generation capacity. There is no generally accepted "maximum" level of wind penetration. The limit for a particular grid will depend on the existing generating plants, pricing mechanisms, capacity for storage or demand management, and other factors. An interconnected electricity grid will already include reserve generating and transmission capacity to allow for equipment failures; this reserve capacity can also serve to regulate for the varying power generation by wind plants. Studies have indicated that 20% of the total electrical energy consumption may be incorporated with minimal difficulty.[41] These studies have been for locations with geographically dispersed wind farms, some degree of dispatchable energy, or hydropower with storage capacity, demand management, and interconnection to a large grid area export of electricity when needed. Beyond this level, there are few technical limits, but the economic implications become more significant.

However In evidence to the House of Lords Economic Affairs Select Committee, the UK System Operator, National Grid have quoted estimates of balancing costs for 40% wind and these lie in the range £500-1000M per annum. "These balancing costs represent an additional £6 to £12 per annum on average consumer electricity bill of around £390."[42]

At present, few grid systems have penetration of wind energy above 5%: Denmark (values over 18%), Spain and Portugal (values over 9%), Germany and the Republic of Ireland (values over 6%). The Danish grid is heavily interconnected to the European electrical grid, and it has solved grid management problems by exporting almost half of its wind power to Norway. The correlation between electricity export and wind power production is very strong.[43]

Denmark has active plans to increase the percentage of power generated to over 50%.[44]

A study commissioned by the state of Minnesota considered penetration of up to 25%, and concluded that integration issues would be manageable and have incremental costs of less than one-half cent ($0.0045) per kWh.[45]

ESB National Grid, Ireland's electric utility, in a 2004 study that, concluded that to meet the renewable energy targets set by the EU in 2001 would "increase electricity generation costs by a modest 15%"[46]

A recent report by Sinclair Merz[47] saw no difficulty in accommodating 50% of total power delivered in the UK at modest cost increases.

Well I'm not going to argue with you about this, but I think I'll wait until I see a country producing anywhere near 50% of their electricity from wind and not exporting a huge portion of that before I start yelling from the belfries. Papers are one thing, actually demonstrating it is another. TastyCakes (talk) 18:12, 20 November 2008 (UTC)

Well, sure, there will always be some problems when going from the lab to the field, but the scientists and engineers will stay on the problem and make it work. There were also problems with every other type of utility-scale energy. Is exporting wind-generated electricity a bad thing? The world maintains vigorous trade in many other forms of energy: petroleum, natural gas, coal, uranium, etc. Trade is only possible between willing sellers and buyers, which means Denmark cannot export its transient wind surpluses unless its neighbors want to buy the electricity - presumably the buyers perceive a benefit, I doubt they are simply handing Denmark a favor. Other energy markets resolve geographic imbalances between supply and demand; Saudi Arabia, for example, exports most of its petroleum extraction. While the energy trade can cause some problems, until now I hadn't heard of someone objecting to, say, petroleum because the markets are far from the wells. Do you consider the electricity trade between member nations of the European Community to be different than that between the member states of the United States, or the provinces of China? China and the U.S. constitute vast electricity markets comparable in scale to all of Europe, and in all three of those markets huge amounts of electricity shift around in constantly changing patterns, depending on when the hydro plants have strong flow, or when a nuclear plant goes offline for a month, etc. The city of Los Angeles already imports electricity from all over the western U.S. Even if wind were not a factor, France would still be exporting some of its nuclear-generated electricity to improve the economics of its nuclear plants, and Norway would want to link its hydro plants into its neighbors' grids to deal with the seasonal intermittency of its river flows (during the Nordic winter, precipitation accumulates as snowpack, which melts in the spring to replenish the reservoirs; Norway would rather use wind power in winter, when available, than burn its dwindling supply of natural gas). Norway can soak up Denmark's excess wind power, to conserve water for its hydro plants. I can't imagine what is objectionable about such trade. It seems no different to me than Ohio importing coal from Wyoming's Powder River Basin (other than wind being vastly cleaner than coal of course). Moving coal around is not difficult; we have railroads and river barges in the U.S. Yes, the growth in wind power is going to force the construction of SuperGrids and Smart grids, but we would want to do that anyway to gain better efficiency and sharing of transient surpluses. If someone wants to draw a line around a small village and run it 100% from local wind, then some sort of energy-storage technology will be necessary (e.g., Wind-hydrogen hybrid power systems, or a big pile of biomass to feed a biogas plant or a combined heat and power plant, or maybe someday ultracapacitors such as if EEStor makes good on its hype) - these types of projects have only been done on relatively small scale so far. But maybe storage technology will improve in the next 10 or 20 years, as might smart grid technology. We can expect Moore's law to continue making equipment smarter - perhaps someday, electricity grids will be able to shed loads gracefully in response to loss of supply, in the order of priority determined in advance by each consumer. --Teratornis (talk) 00:30, 21 November 2008 (UTC)

I don't dispute anything you're saying, my argument (as spelled out below) is that a small country generating a high percentage of its electricity with wind is fundamentally different than the system overall generating a high percentage of its electricity with wind. TastyCakes (talk) 16:34, 21 November 2008 (UTC)

What is your problem with exporting wind power? Thats the whole point of interconnection - you export surpluses and re import it during times of low wind, becasue it is much cheaper than storage or running backup plant - as does Denmark....Engineman (talk) 01:33, 21 November 2008 (UTC)

I have no problem at all with exporting power. But it completely changes the argument. Achieving 50% of all the electricity generated within the complete system (say the European or North American grids) may be completely implausible, but a small country (or state/province) could quite conceivably make 50% of the electricity it generates with wind and then export it to a relatively large nearby market. Do you see why I consider that to be a misleading argument for what percentage society as a whole can rely on wind power? In Canada, PEI is talking about becoming just such an exporter, but PEI is tiny so it really doesn't matter. People that live on a wind farm could generate 100% of their electricity from wind and "export" 99% of it, and that's fantastic. But it doesn't really prove anything about the big picture. Also, please put your comments at the bottom of the discussion and stop cutting off other peoples' stuff. TastyCakes (talk) 16:30, 21 November 2008 (UTC)

[edit] NPOV

There has been a lot of talk about the articles on wind and intermittent power sources. not having NPOV over the issue of intermittency, as if there is some sort of debate and wikipedia has to show some balance. But there is no debate. None of the professional studies have shown any insurmountable and unaffordable problems with integrating large, ie over 50 % wind into power systems. It should not have to be for those who have read these sources of information to have to defend against a non existent case. There is simply no professional evidence to the contrary. So the NPOV is quite simply that intermittency of large amounts of wind is a non issue - to the extent that it can be dealt with using known techniques and that it does not impose major costs or unreliability on power systems. If you disagree with this, please cite some professional studies. Engineman (talk) 06:33, 21 November 2008 (UTC)

You talk in absolutes a lot... In case you forget, the reason I brought all this up in the first place was the line someone (you?) put in the intro:

The intermittency of wind seldom creates problems when using wind power to supply a low proportion of total demand. Where wind is to be used for a moderate fraction of demand, additional costs for compensation of intermittency are considered to be modest.

My problem with it as the intro of a Wikipedia article are, I think, obvious: it doesn't really say anything concrete, but it says it in such a way to suggest everything is totally awesome with wind. How about adding what constitutes "seldom", "problem", a "low proportion", a "moderate fraction" and "modest additional costs"? Surely if there is as strong a consensus on the generalities as you suggest, there is similar agreement on the concrete definitions of these terms?

You say intermittency is no more of an issue than any other generation method. I'm sorry but I have not been convinced of this: wind by its very nature is unpredictable and I am sure designers of electrical systems with a large wind component have to consider intermittency (particularly unpredictable intermittency) more than designers of, say, a coal plant. Saying the issues have been effectively tackled is one thing, saying they are "non-issues" is another. TastyCakes (talk) 16:42, 21 November 2008 (UTC)

Dear TastyCakes - actually I didn't write the intro but it is a perfectly clear and accurate summary of the opinion reached by experts who have reviewed all sorts of other expert reports and data - have you read the UKERC report which more or less ends up saying what the intro says? I don;t think it is for me to convince you of anything, its the other way round. All the expert evidence, is that whilst intermittency is clearly a factor, it is not a limiting issue, and that wind can therefore economically supply energy in large grids. Have you read the IEA article and Czisch' papers ? - he indicates 70% wind is economic, ? You may not like it, or think it is true, in an engineering sense, but that is the view contained in the engineering and economic evidence? You keep saying you don;t accept this, but can i ask, on what evidence, other than your own opinion? Have you done any modeling? Have you published anything? Which expert articles lead you to your misgivings?

I have read some of the papers and am in the process of reading others. As I am not in the business of wind power, nor an expert on the matter by any means, I of course have not published or modeled anything. Have you? Are you aware of wikipedia's policy of original research? TastyCakes (talk) 19:04, 22 November 2008 (UTC)

I think you queried somewhere why nuclear needed pumped storage - its really the opposite of winds issue - its is generally flat in output, and in UK the pumped storage was intended to take nighttime nuclear and use it during the daytime peak. Nuclear is also very intermittent - 6 months ago blackouts occurred in UK because Sizewell B nuclear power station suddenly sloped - 1.2 GW in micro seconds - far worse rate of change than a wind farm closing down, which at least will have a weather forecast. Denmark is by the way aiming for 50% wind by 2050 I think.Engineman (talk) 03:04, 22 November 2008 (UTC)

So you are saying pumped storage is as vital and integral to nuclear as to a high % wind power scheme? TastyCakes (talk) 17:17, 22 November 2008 (UTC)

I really don't think you're addressing the things I'm saying here. Does anyone else care to weigh in? Is it really plausible to generate 70% of humanities electricity through wind? 50%? Is the sentence I've taken issue with in the intro really clear, accurate and neutral? Like I said earlier, I really don't want to argue about this stuff with you (engineman). I just think the last sentence in the intro is poor. TastyCakes (talk) 07:54, 22 November 2008 (UTC)

The question is not whether you (or anyone else here) thinks it is plausible or not to generate 70% of electricity from wind. The question is, are there any reliable sources that claim that integrating large wind power is a problem? Splette :) ^{How's my driving?} 08:14, 22 November 2008 (UTC)

I agree. TastyCakes (talk) 17:17, 22 November 2008 (UTC)

The original claim was that "for a moderate fraction of demand, additional costs ... are considered to be modest." Are you saying that 70% is a "moderate fraction"? Extraordinary claims require extraordinary evidence. Engineman's UK report characterizes >20% as "high penetrations".

—WWoods (talk) 20:37, 22 November 2008 (UTC)

Dear tasty cakes - you might want to look at thus presentation - http://www.claverton-energy.com/download/156/

the author is the ex director of the West Denmark Power Grid, where as he says they are studying, and indeed planning for 50% wind by 2025. It looks like in the long term they are expecting 100% renewable. Dr Czisch has modelled 100% renewable, 70% wind and 30% biomass chp http://www.claverton-energy.com/european-super-grid.html. Suggest you read his study. The UKERC study brings together numerous previous studies and pretty much says that there are no problems in 20% wind penetration by energy supply http://www.claverton-energy.com/download/145/ which is the point yu seem to take issue with. Have you read these? Can you cite any evidence which supports your view? Engineman (talk) 10:31, 22 November 2008 (UTC)

My view that high wind penetration is not a trivial matter that is a "non-issue"? The claverton page you cite gives very interesting and exciting claims. But do they not all depend on a European supergrid? Is the creation of such a grid a trivial technical matter? The site itself says "This largely confounds the claims of various energy experts who claim renewables cannot meet UK power needs", and (from the former head of Shell): "Real time balancing of current flows in super grids is a massive unsolved technical challenge, but it is one that we have to face". The page suggests that they are of course wrong, but it certainly doesn't mesh with your claim that "there is no debate" on this matter.

The view from the UK electrical board is also interesting. Perhaps you missed page 10 where in recommendations for future studies it includes:

Options for managing the additional power fluctuations on the system due to intermittency –including new supply technologies, the role of load management, energy storage etc. Opportunities and challenges for re-optimisation of the electricity system in the long term to cope with intermittent generation, including research on much higher penetrations of renewable sources than the relatively modest levels considered in this report. (bold added)

Indeed, if you read the report you will see they are talking about penetration up to 20%. It should also be noted that articles in the Economist and elsewhere like this one continue to cast dispersions on the claims of Britain fulfilling 15% of its energy needs with renewable sources by 2020. This paper says vastly increasing Germany's reliance on wind power would be difficult if not impossible due to unavailability of pumped storage capacity. And the fact that all of your sources give different maximum penetrations makes it seem to me that the debate is not over.

But you have dodged the jist of my argument yet again. The sentence in the intro is totally unquantified. That may be alright in the conclusions of a fluffy government report talking about how vital it is to get Britain off of fossil fuels, but that does not make it suitable for an encyclopedia entry. When it says "low proportion of demand", does it mean 1%, 5%, 20%? When it says moderate portion of demand does it mean 10%, 20%, 50%? When it says compensation for moderate demand is modest, does it mean the construction of unproved technology such as a super grid or the use of pumped storage that may or may not be available to all countries in all situations? By failing to have this in these sentences it is missing the objectivity the intro should have.

I'm not trying to dump on anyone's parade here, I think wind power is a fantastic technology that is going to grow immensely in the coming decades. But I think it is premature to make claims like the ones implied in the intro sentences. A lot of respected groups have published reports that do not predict overall (ie not for relatively small countries such as Denmark) high wind penetration in the coming decades, such as this one by the NPC and this new one from the IEA (see page 10). The only reason I can see for that being the case is that they remain to be convinced that the technical, logistical and economic challenges facing a high percentage of wind adoption have been solved. So yes I do bristle when you brush such issues aside by throwing hundreds of pages of semi-relevant reports at me. TastyCakes (talk) 19:04, 22 November 2008 (UTC)

To reply to the earlier question of whether pumped storage is essential to nuclear power: basically, yes. See Pumped-storage hydroelectricity#Worldwide list of pumped storage plants - most of those plants were built years before wind power became significant, to perform diurnal load-leveling with coal and nuclear plants, whose operating characteristics are almost as mismatched to demand as wind is, although for what we might consider an "opposite" reason, wanting to operate at full output around the clock, whereas demand may vary by more than a factor of two on a daily basis. However, most pumped hydro storage plants have a limited capacity, only perhaps one or two days of full output at most, so they are good for daily peak power; they cannot by themselves compensate for extended unscheduled outages of a nuclear plant, which may go down for weeks at a time. (However, pumped storage would still help with meeting the daily peak demand, as other baseload plants could help charge them up at night while the nuclear plant gets repaired.) Nuclear plants don't fail very often, but when they do, the impact of a single failure may be worse for the grid than the worst-case failure for a collection of geographically dispersed, interlinked wind farms. For all the wind farms to go down and stay down for weeks might be a once in 500 years weather event (the exact figure would become clearer after the farms had accumulated some years of operating data), but for a nuclear plant a failure of comparable magnitude is common enough to be a familiar event. This is not an argument against nuclear power, just an observation that nuclear power creates its own grid-management problems, but grid operators figured out how to solve them (although not 100% of the time, there are still occasional blackouts), and these problems are not showstoppers for nuclear power. --Teratornis (talk) 19:32, 22 November 2008 (UTC)

The availability of grid energy storage may be a limiting factor for the maximum share of wind power on particular grids. Suitable sites for conventional pumped hydro storage may be limited. However, people are working on alternatives such as Compressed air energy storage, underground reservoirs for pumped hydro, ultracapacitors, Vehicle to grid, etc. Ultracapacitors are interesting because they could become cheap and powerful enough to replace on-site Emergency power systems. As more consumers integrate their backup generation or storage into a Smart grid, the resulting virtual grid storage plant would have the advantage of incremental expandability and distributed robustness. This is in contrast to pumped hydro plants which typically require years to build, and then also present a single point of failure. --Teratornis (talk) 19:48, 22 November 2008 (UTC)

Lots of power consumers already install Emergency power systems, even before wind power achieves high penetration. This suggests that the existing power mix has enough reliability problems to motivate consumers to see to their own power security. The present technology for emergency power relies undesirably on diesel or gasoline from petroleum. Consumers would presumably prefer to store electrical energy from the grid, since the energy would be cheaper than liquid fuel, and refueling would be automatic. If ultracapacitors become cheaper than diesel generators for emergency backup, this would allow for almost any penetration of wind power. The home or business backup units could pay for themselves with a smart grid that spot-prices electricity according to its availability. I.e., when the wind is blowing, electricity becomes cheap, and all the smart backup units soak up all the power they can. --Teratornis (talk) 20:00, 22 November 2008 (UTC)

One might view tiny Denmark's export of wind power as somehow "cheating" on the intermittency problem, because it raises the question of what happens when everybody else installs lots of wind power. Who will Denmark then export to? Well, as we know, the wind blows differently in different places. When the wind is blowing hard in Denmark, it might be calm in Spain, and vice versa, hence the need for a SuperGrid. But even if Denmark had no connections with its neighbors, in the worst case it could shut down some wind turbines temporarily in the event of more wind than it can use. This would merely be a loss of some potential revenue, not a technical failure of its wind system. When the wind stopped blowing, Denmark could restart its fossil plants. The maximum percentage of annual electrical energy that Denmark could obtain from the wind would depend on how much grid energy storage it had, to avoid running its fossil plants during low-wind conditions. The maximum percentage would almost certainly be higher than the economically optimal percentage, depending on how one chooses to price the carbon-based fossil fuels. It's hard to talk about the maximum penetration of wind power right now because all of the major power grids are years away. Thus we are discussing a future problem, and Wikipedia is not a crystal ball. The picture in ten years might be very different, after people have had ten years to attack the intermittency problem, along with an increasing motivation to attack it. Also note that nobody is going to install 100% wind power, other than perhaps a few isolated settlements. Wind power is merely the first of the so-called "new renewables" to become economically viable. Other renewable sources such as Solar power and Hot dry rock geothermal energy appear to be nearing economic viability, and as their availability characteristics are much different than wind, they will tend to offset its intermittencies to some extent. We can also expect further technical improvements in wind power, such as building more wind farms offshore, and using taller towers, which increase the capacity factor. If airborne wind turbines ever work, then wind power has the same capacity factor as nuclear (up to 90%, as high-altitude winds can be very consistent). We can have high confidence that Moore's law has some years left to run, which means that in ten or twenty years when wind power is getting big, embedded computers will be up to thousands of times smarter than what we can build today. Even if there wasn't going to be any wind power, there was already motivation to build the Smart grid because of the high economic costs of the blackouts we are having already. Having said all that, I agree as I stated before that the vague sentence in the lead section violates WP:WEASEL and needs to become more specific. If nothing else, we should clearly state who is claiming the "modest costs" and for what specific grid. --Teratornis (talk) 20:28, 22 November 2008 (UTC)

From http://www.claverton-energy.com/download/145/ :

27. The aggregate ‘costs of intermittency’ are made up of additional short-run balancing costs and the additional longer term costs associated with maintaining reliability via an adequate system margin. Intermittency costs in Britain are of the order of £5 to £8/MWh, made up of £2 to £3/MWh from short-run balancing costs and £3 to £5/MWh from the cost of maintaining a higher system margin. For comparison, the direct costs of wind generation would typically be approximately £30 to £55/MWh. If shared between all consumers the impact of intermittency on electricity prices would be of the order 0.1 to 0.15 p/kWh.

I.e. a premium of ~15%. Not huge, but not "no problems" either.

28. These estimates assume that intermittent generation is primarily wind, that it is geographically widespread, and that it accounts for no more than about 20% of electricity supply. At current penetration levels costs are much lower, since the costs of intermittency rise as penetrations increase. If intermittent generation were clustered geographically, or if the market share were to rise above 20%, intermittency costs would rise above these estimates, and/or more radical changes would be needed in order to accommodate renewables.

From "Analysis of Wind Power in the Danish Electricity Supply in 2005 and 2006" link to pdf here /