Talk:Wind power/Archive 4

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Capacity Factor - Misleading

Within the intoduction to the article is stated

“ "At the end of 2006, worldwide capacity of wind-powered generators was 73.9 gigawatts." ”

however further on in the article in the 'Wind Energy' section subsection 'Capacity Factor' is stated

“ "Since wind speed is not constant, a wind generator's annual energy production is never as much as its nameplate rating multiplied by the total hours in a year. The ratio of actual productivity in a year to this theoretical maximum is called the capacity factor. A well-sited wind generator will have a capacity factor of about 35%." ”

Furthermore throughout this article are numerous instances of capacity figures that are almost all silent on whether this is a peak or average capacity number. For a general reader this lack of detail is misleading, particulary because of the large difference between average and peak (35% and 100%). This is not a criticism of Wind Power but simply accuracy. These same issues are also applicable to other electrical power generation method's capacity factors, for instance coal powered plant capacity changes due to cooling tower effectivness variablity with temperature, humidity and water availability.

I propose the following:

Capacity figures be prefixed or postfixed with peak eg. "worldwide peak capacity of wind-powered generators was 73.9 gigawatts" or "73.9 gigawatts (peak)" or include both peak and average eg. (73.9/25.9) or (73.9 peak / 25.9 average) Although this is dealt with in a specific section 'Capacity Factor' it is not applied throughout the article as it should be for accuracy and clarity, and this limits the development of the article in the areas of, for instance, differences in load factors seasonally or in different regions or between land and sea based sites. What do you think?

Theo Pardilla 03:03, 6 January 2008 (UTC) —Preceding unsigned comment added by Theo Pardilla (talk • contribs)

I object. You can't add all the wind turbines in the world and assume an average capacity factor. No grid-connected generating plant operates at 100% nameplate rating for 100% of a year. The convention in the electrical industry is always to give the nameplate rating of generators of a plant (less, if necessary, plant internal conumption) as the capacity, and then discuss capacity factors as relevant. A total rating (megawatts, gigawatts) is necessarily a power rating, and the capacity factor gives the ratio of actual annual energy production compared with nameplate rating multipled by 8760 hours/year. I suggest the "expand" tag is unnecessary and should be removed. --Wtshymanski (talk) 18:14, 6 January 2008 (UTC)


Whilst I agree with Wtshymanski's statement that all grid connected generating plants operate at sub 100% nameplate and continuous rates, articles are intended for a non specialist or non technical readership and the quantification of power output is deceptive therefore as it does not specify that this figure is a maximum peak number. This differs qualitatively from most other grid connected generation technologies in that its maximum long term average is around 1/3rd of its peak or nameplate rating, due primarily to reliance on uncontrollable wind patterns, whereas gas, coal or nuclear can have a maximum long term average of around 90%. Maximum capacity factors for wind power will of course depend upon local and regional wind patterns and although you may not want to 'assume' an average global capacity factor you can calculate an estimate based upon general scientific models and refine it as needed. The 1/3rd figure seems, according to the literature, to be about right. However this does not obviate the need for a subsection about Capacity Factors. Sure you can run a gas generator at sub 90% rates say 25 or 10, but the inherent maximum capacity is around 90 or so and is near enough to 100 to not need to give prominence to capacity factory clarification. You havent addressed my main point that an unclarified power rating maximum is misleading for a general audience, and whilst a section in the article devoted to capacity factors is necessary, it does not relieve the requirement to prominently differentiate peak and maximum average power. Would your position still hold if maximum capacity factor was 3% or .3%? It should be self evident that a figure circa 33% is different from a circa 90% figure by a substantative order of magnitude to the extent of qualitative difference, and whilst you may well agree with this observation I believe that it follows from this that prominence be given to differentiation at the point of enumeration of power rating for the purposes of clearly conveying these differences to a general reader. Electrical industry power rating conventions are based on base load continuous generation at high rates of 70, 80 or 90% ranges and are therefore inapplicable to windpower in exactly the same way.

--Theo Pardilla 14:25, 11 January 2008 (UTC)

That was very long. Electrical industry practice is to give the nameplate rating of the generators, less any in-house consumption. Intermittency is very prominent in the article now. No-one but an oil sheik can afford to run a natural gas-fired plant at 100% capacity factor at current NG prices, not while there's any more economical base load (desalination plants are the obvious exception, but they tend to be in the Mideast gas-producing countries for just that reason). "Maximum average" is meaningless in this context. If the capacity factor was 3% no-one would be building wind plants. --Wtshymanski (talk) 15:08, 11 January 2008 (UTC)
The capacity factor issue for wind power is qualitatively different than for traditional power generation and I can see no downside in being extra clear when the article is talking about peak power vs annual average.--agr (talk) 17:37, 11 January 2008 (UTC)
The capacity factor is defined the same way for all sources and so is directly comparable. Most hydro plants, in my experience, do not have enough water capacity to run at full nameplate output for a year - they are sized to harvest energy when it's available and produce at lower levels the rest of the year. --Wtshymanski (talk) 17:47, 11 January 2008 (UTC)
It's fine to cite nameplate capacities when describing wind in a vacuum, but if you're comparing a 20% capacity factor wind farm with a 50% capacity factor hydro plant with an 85% capacity factor nuclear plant, it's certainly misleading to only cite the nameplate capacities. — Omegatron 10:22, 16 March 2008 (UTC)
"Wind in a vacuum" is a delightful phrase I'm sure I'll never see used anywhere but on the Wikipedia. Agree, annual production is a better measure of contribution to an energy balance than capacity, but everyone reports capacity. --Wtshymanski (talk) 16:51, 16 March 2008 (UTC)

You seem to have missed the points.

No-one opposes clarifying prominently capacity factors when there is no downside except ideological, inertial or cognitive, no-one. Simply reciting "Electrical industry practice is to give the nameplate rating of the generators" is an inadequate substitute for refinement. Wind power can never provide capacity factors averaged over the long term in the 70s 80s or 90s as its simply an inherent limitation from variable wind patterns and whilst there may well be some areas of the world where its theoretically possible to have much higher capacity factors than 35% such as the Antactic its simply impossible almost everywhere else. No-one thinks that fuel costs are relevant to physical, intrinsic capacity limitations, No-one. Not even the most profligate wealthy can make the wind blow continuously and they cannot change the laws of physics. Wind is limited to 35% but GHG and Nuclear plants can run at near 100% and are not inherently retarded by physics.

--Theo Pardilla 12:37, 17 January 2008 (UTC)

A late insertion: I agree with your observation about ground-mounted wind turbines, but airborne wind turbines might actually be able to obtain capacity factors rivaling nuclear power plants, as high-altitude winds are very steady in many parts of the world. --Teratornis (talk) 05:44, 9 April 2008 (UTC)
Yes, I am completely missing the point. What are you trying to say that the existing (as of January 17,2008) section oncapacity factor does not already say? Barring any naive AIs reading the Wikipedia. I think our readers understand that the wind blows where and when it wills, and the section shows the engineering and economic impact of the wind's variability. (The St. Leon guys told me their capacity factor was 40% in 2006 but I don't have a published reference for that.) --Wtshymanski (talk) 18:21, 17 January 2008 (UTC)
Capacity factor of a single turbine at some academic institution is not representative of capacity factors of wind farms financed by cold-eyed accountants watching the bottom line. I suspect real wind farms don't disclose their operating statistics on a real-time basis because this is sensitive commerical information (I'd like to see a real wind farm with a real-time display - not just one turbine!). Nor is a lash-up of solar panels and wind turbines feeding your geodesic dome representative of commercial wind farms, which do not have anything to do with solar panels - the complementarity is only relevant to the geodesic dome crowd, and good luck to 'em. Capacity factor has very littel do do with blade design and *everything* to do with where you put the darn things; even Grandpa's Knob had a 32% capacity factor till it fell apart and that was more than 60 years ago. --Wtshymanski (talk) 19:16, 24 January 2008 (UTC)
The first reference states: "A reasonable capacity factor would be 0.25 to 0.30. A very good capacity factor would be 0.40." And later: "In recent years, the U.S. wind industry has begun using seemingly insignificant refinements in blade airfoil shapes to increase annual energy output from 10 to well over 25 percent." The siting is important, but for a given location, blade design is extremely important in improving capacity factor. Grandpa's Knob may have been a particularly good location. Find a spot with constant winds, and you can expect a whole lot higher than 40% capacity factor. Be careful not to confuse efficiency with capacity factor. The second reference says that "Typical wind power capacity factors are 20-40%." When you give a total range of 20 to 40% it is redundant to say that 40% is obtained from particularly favorable sites. When you say that typical values range from 20 to 40% it is implicit that actual values both exceed and are lower than the endpoints, which is why "particularly favorable" needs to be identified as "more than 40%", not, "at the upper end of the range". This is just plain logic. I'm looking for data from wind farms as well. So far I have a few small turbines, plus the 660 kW turbine. The reference which was deleted says that the best locations are Northern Europe along the North Sea, the southern tip of the South American continent, the island of Tasmania in Australia, the Great Lakes region, and the northeastern and northwestern coasts of North America. You can read that from the abstract, no need to buy the article. The Strait of Magellan is famous for having very constant winds. Put a wind farm there and you will be hugely higher than 40% capacity factor. 199.125.109.38 (talk) 04:48, 26 January 2008 (UTC)
For not quite "real-time" but hourly archives, see Ontario system operator's data. Currently five windfarms with capacity and actual average output per hour. There are a few articles on the web that have done some analysis of actual capacity factors, as I recall running consistently 25-30% annually, plus seasonal variation.--Gregalton (talk) 06:17, 26 January 2008 (UTC)
Excellent. This is just what I was looking for. Now I need ones for Europe and the United States. This is a massive amount of data to go through, though.
 Wind farm       Location              Capacity in MW Capacity factor in 2007
 ----------------------------------------------------------------------------
 Amaranth I      Township of Melancthon        67.5    30.61%
 Kingsbridge I   Huron County                  39.6    35.03%
 Port Burwell    Norfolk and Elgin Counties    99      28.05%
 Prince I&II     Sault Ste. Marie District    189      28.82%

Wind Power in Ontario

199.125.109.38 (talk) 08:31, 26 January 2008 (UTC)

Unfortunately, I haven't found any sources as detailed as this for other geographies. You may also want to keep in mind/take a look at when these came online - I believe three of the four came online in 2006.
This is not so much a question for talkpage, but I have interest in doing some more detailed analysis of the coincidence / correlation with other generating sources/demand/prices. I don't, however, have the xml/coding skills. You can talkpage me if this is the type of thing you're interested in.
I should have noted that there is lots of other data, but raw and overviews, available on how the IESO looks at all the aspects of wind integration in a good-sized system.--Gregalton (talk) 11:38, 26 January 2008 (UTC)


intermittency in intro

"Wind energy is plentiful, renewable, widely distributed, clean, and reduces toxic atmospheric and greenhouse gas emissions if used to replace fossil-fuel-derived electricity. The intermittency of wind seldom creates problems when using wind power at low to moderate penetration levels.[4]"

Although I heavily favor wind power, I still sense how twisted-POV this last sentence of the intro is (it denies a problem without ever acknowledging the problem). It would be much more straight-forward and honest to say instead something like: "The variability (intermittency) of the wind is a potential problem, especially when it supplies a large percentage of the power in a system, but ameliorating techniques have been developed that are adequate in most applications." -69.87.203.168 (talk) 03:22, 24 November 2007 (UTC)

I agree. I also strongly support windpower but the last paragraph of the intro seems too POV. I'm not sure any comments on the advantages or disadvantages of wind power need to be addressed in the opening introduction as they are sufficiently addressed later. I think this last paragraph should be removed completely (and/or moved elsewhere?).Ga2re2t (talk) 21:19, 4 December 2007 (UTC)
Do you have a problem with the current wording "The intermittency of wind seldom creates insurmountable problems when using wind power to supply up to roughly 10% of total electrical demand (low to moderate penetration), but presents challenges that are not yet fully solved when wind is to be used for a larger fraction of demand.[1]" It seems accurate and well sourced.--agr (talk) 16:49, 5 December 2007 (UTC)
I have a problem with it. The reference is a year old. Later on in the article it states that Minnesota did a study that found that the cost of 25% wind was minimal and later on that Denmark gets 20% of their electricity from wind. The lead needs to be rewritten. I believe that more recently 70% has also been considered, combined with solar which tends to have a reverse intermittency from wind, and supplemented with pumped storage. 199.125.109.108 (talk) 02:33, 23 December 2007 (UTC)
Intermittency is usually brought up as the ultimate deal-killer on wind power. However this is like saying that the lack of railways were an obstruction to the introduction of rail transport, which could not run on the regular roads, or that the lack of power lines was an obstacle to the widespread use of electricity. It is not an insurmountable problem, and many solutions exist. First is having a large grid system, which evens out the system. Second to the transmission problems in this, is the HVDC system proposed in Europe. [2] Third is the construction of a system of new pumped storage systems and fourth is the management of demand, using real-time pricing according to supply. Fifth would be a fast-tracking to produce a viable electric car, by breaking the battery-patent/Chevron logjams and suchlike, allowing cars to be recharged at peak supply times, as well as storage heaters, storage coolers, mobile-phone rechargers, etc etc etc. Put all these together and you will wipe out any intermittency problems. Adding Solar Power will also help to manage peak demand during the day. Lets face it folks, fossils are in the past. We can live in the problems of the past or we can look for solutions in the future. - Mike —Preceding unsigned comment added by 83.147.143.193 (talk) 17:32, 5 January 2008 (UTC)
Rest assured, if wind was all the energy source there was, intermittancy solutions would be found. Brute-force solution is building far more capacity than you need for peak demand, and interconnecting it - rather like some hydro systems are built, now. More elegant (less costly) solutions would invovle storage. Intermittency is an economic issue, not a fundamental physical limit. --Wtshymanski (talk) 16:39, 7 February 2008 (UTC)
Another option is to use excess wind power to generate hydrogen for use in sustainable ammonia production. Currently ammonia production consumes large quantities of natural gas, and that is obviously unsustainable. Eventually we'll have to generate the hydrogen by electrolysis of water. Ammonia plants would be excellent captive users of wind power, since it's easy to store hydrogen on-site to buffer the power input. --Teratornis (talk) 05:54, 9 April 2008 (UTC)

The best way to fix the lead is change 10% to 20%. Low to moderate penetration would be say 5% to 30%. Low penetration would be 1 to 10%. Moderate penetration is definitely not 10%, and since Denmark is having no problem with 20% that is what the lead should say, 20%. Newer studies show that even 60% penetration can be accommodated with no difficulty. See the study about the cost of using 70% for example. The combined power plant developed in Germany used 60.9% wind, 14.3% solar and 24.8% biomass. 0.5% was imported and 4.1% was exported; and 1.4% was lost by sloshing it back and forth in hydrostorage. What they were demonstrating was that Germany can get 100% of electricity from renewable energy. 199.125.109.57 (talk) 07:10, 16 February 2008 (UTC)

On intermittancy, have there been any studies on intermittancy on large scale wind-power production ? I can imagine that when the wind doesn't blow in Northern Europe, it would blow in Southern Europe and vice-versa, Just because the earth keeps turning.

Spelling

My dictionary shows complementariness as a noun, but I sure never have heard of it before. Easier to just say "this". Complementarily, the adverb, is a little more familiar, but not much. 199.125.109.57 (talk) 20:02, 9 February 2008 (UTC)

External link: video illustration

Is anybody going to strongly object to me adding a link to this video (requires flash) in the safety section, as a good illustration of what can go wrong? Having looked at WP:EL, you could probably argue either way about whether or not is should be in. Guinness (talk) 12:07, 23 February 2008 (UTC)

I don't know about this - is there some context for the video? Dates, age of machine, owner, location, etc? The fact that a crew turned up to record the event makes me wonder if this wasn't a delibrate trial. Videos of dams bursting, boilers collapsing, and Geiger counters clicking are all well and good but are they relevant to normal operations of the respective energy sources? --Wtshymanski (talk) 18:22, 23 February 2008 (UTC)

I'm planning on starting an article on wind power accidents, and started a list of youtube videos:

  1. Denmark turbine exploding from overspeed in a storm:
  2. Turbine fire (Spain?) http://www.youtube.com/watch?v=HKkTUY2slYQ
  3. Turbine fire (location?) http://www.youtube.com/watch?v=EgXcHzi2t4s
  4. Turbine fire (Palm Springs, CA) http://www.youtube.com/watch?v=4N4HQv-UyUo
  5. Turbine destroyed by lightning along a road
  6. Fenner, NY blade failure
  7. Wayne County, PA blade failure
  8. Fire caused by downed wind farm power lines

Probably don't want the entire list in this article, of course.  :) — Omegatron 23:33, 12 March 2008 (UTC)

Oh and while you are at it how about a list of all automobile accidents? Neither seems to be particularly notable. 4.233.143.3 (talk) 18:12, 14 March 2008 (UTC)
List of civilian nuclear accidents, List of military nuclear accidents, List of coal mining disasters, List of mining disasters in Poland, List of accidents and incidents on commercial aircraft, List of rail accidents, List of horse accidents, ... — Omegatron 23:31, 14 March 2008 (UTC)