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Clean Power wind turbines capacity factor lcoe

Published on July 27th, 2012 | by Zachary Shahan

186

Wind Turbine Net Capacity Factor — 50% the New Normal?

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July 27th, 2012 by Zachary Shahan 

wind turbines capacity factor lcoe

Wind turbines via Shutterstock

Anyone who hangs around in the comments section of sites covering wind energy knows one thing — clean energy haters love to talk about wind turbine capacity factor. In particular, they love to chant the now quite untrue claim that wind turbines have a capacity factor of 20-30%.

If you’re not familiar with capacity factor, it is how much electricity a power plant actually produces compared to how much it would produce if it operated at full nameplate capacity 100% of the time.

No power plant operates at 100% capacity factor. NREL’s new Transparent Cost Database shows the following capacity factors:

  • natural gas combustion turbines — Minimum: 10%; Median: 80%; Maximum: 93%
  • natural gas combined cycle — Minimum: 40%; Median: 84.6%; Maximum: 93%
  • coal, pulverized & scrubbed — Minimum: 80%; Median: 84.6%; Maximum: 93%
  • nuclear — Minimum: 85%; Median: 90%; Maximum: 90.24%
  • biopower — Minimum: 75%; Median: 84%; Maximum: 85%
  • hydropower — Minimum: 35%; Median: 50%; Maximum: 93.2%
  • enhanced geothermal — Minimum: 80%; Median: 90%; Maximum: 95%
  • solar PV — Minimum: 16%; Median: 21%; Maximum: 28%
  • offshore wind — Minimum: 27%; Median: 43%; Maximum: 54%
  • onshore wind — Minimum: 24%; Median: 40.35%; Maximum: 50.6%

–> For a look at one of the most innovative and high-tech wind turbines today, check out CleanTechnica’s exclusive write-up of the GE Brilliant 1.6-100 wind turbine.

Where Does Capacity Factor Fit Into Things?

Now, before moving on to the focus of this article, here’s one more thing to note:

Clean energy haters love to talk about capacity factor because it’s clearly a metric wind, solar, and hydro don’t win at (though, geothermal and biopower actually do very well). However, capacity factor by itself is really not that important. What’s important is the total cost of producing electricity. In the energy field, levelized cost of energy (LCOE) is one of the most important metrics. This is “an estimate of total electricity cost including payback of initial investment and operating costs,” as NREL writes.

Capacity factor plays a role in LCOE, of course, but so does free fuel (i.e. wind and sunshine). (In a perfect market, LCOE should also include the cost of pollution, which is not the case at all in the US today.)

Even without the cost of pollution figured in, if you look at NREL’s LCOE tab, onshore wind energy has a median of $0.05/kWh. The only energy source that beats that is hydropower ($0.03).

So, the point is, onshore wind energy is already essentially the cheapest option for new electricity (new hydro is not so cheap — that low figure is based on very old dams), even with NREL’s median capacity factor of 40.35%.

But…

Technology Changes

Wind power is still a relatively new electricity option. The technology is still improving, becoming more and more efficient. And, as a part of that, there has been what is essentially a breakthrough in net capacity factor of various turbines in just the last 2 years.

Chris Varrone of Riverview Consulting, a friend of ours and true expert in this arena, recently noted in an email to me that this is due to a “proliferation of ‘stretch rotor’ machines like the GE 100-1.6MW and the V100-1.8MW and V112-3.0MW…. such machines can often hit 50% capacity factor onshore.”

In other words, new wind turbines are regularly hitting 50% capacity factor, much better than that antiquated 20-30% clean energy haters love to throw around!

More from Chris: “this contrasts with low 30s for the last generation of rotors (e.g., V80-2.0MW) — it is changing the game.”

NREL’s minimum of 24% is old news, old technology. Even turbines in the 30s are old technology now. And the median is being brought down by these older turbines.

New wind turbines are more efficient. And, thus, new wind power is even cheaper. It is now at an all-time low, in fact.

One more note from Chris: “LCOE has declined by 33-45% in the past 3 years in the US!”

–> For a look at one of the most innovative and high-tech wind turbines today, check out CleanTechnica’s exclusive write-up of the GE Brilliant 1.6-100 wind turbine.

Next Time You’re in a Conversation with a Wind Energy Hater

What are the takeaway points?

  1. Wind turbine capacity factors are often 50% these days.
  2. Wind LCOE is 33-45% lower than it was about 3 years ago.
  3. Wind energy is the cheapest option for new electricity in many a location now.

Are you taking anything else away from this? (There are some other key benefits from these improvements…. I’ll mention them in the comments if no one else picks up on them.)

Keep up to date with all the hottest cleantech news by subscribing to our (free) cleantech newsletter, or keep an eye on sector-specific news by getting our (also free) solar energy newsletter, electric vehicle newsletter, or wind energy newsletter.



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About the Author

spends most of his time here on CleanTechnica as the director/chief editor. Otherwise, he's probably enthusiastically fulfilling his duties as the director/editor of Solar Love, EV Obsession, Planetsave, or Bikocity. Zach is recognized globally as a solar energy, electric car, and wind energy expert. If you would like him to speak at a related conference or event, connect with him via social media. You can connect with Zach on any popular social networking site you like. Links to all of his main social media profiles are on ZacharyShahan.com.



  • Parke Ewing

    Per the Energy Information Agency (EIA) EIA.gov your cost figures are not accurate. Why do you post calculations that are not accurate?

    http://www.eia.gov/forecasts/aeo/er/electricity_generation.cfm

  • Parke Ewing

    I call the statement of a minimum wind turbine capacity factor of 24% a complete lie. Ocotillo Wind (Express) has a capacity factor of a very low 17-19%. Evan a 24% CF is too low and not economically viable without the Production Tax Credits, which hopefully will not be renewed.

    • Bob_Wallace

      Wind is now our cheapest source of new electricity production. All energy is subsidized. Take away subsidies and wind is still the cheapest.

      There are wind farms with <24% CF numbers. But that is for older wind farms. New technologies are producing much better CF numbers even in sites with less than excellent wind resources.

  • TruthinMaine

    If all this new technology is leading to such great CF, then it is time to end the PTC for wind and repeal all the heinous, arbitrary RPS. Let wonderful wind compete in the open marketplace for wholesale electricity. As in real estate, wind site output depends on location! location! location! Perhaps the open prairies of the mid-west have the steady unobstructed winds that can nudge up CF, but the PTC and RPS are leading to building industrial wind sites in places that NREL correctly predicted has poor to marginal wind resources like on-shore Maine.

    Capacity
    Factor of Maine’s major wind sites in 2012 was 24.27%, based on wind
    operators’ reporting to FERC. So far this year, the data is running
    very close to last year. See the data for the individuals wind sites in
    Maine here: http://www.windtaskforce.org/profiles/blogs/maine-wind-sites-production-for-entire-year-2012

    • Bob_Wallace

      How about some honesty from you selfish NIMBYs?

      Acknowledge the massive support taxpayers provide for fossil fuel and nuclear energy when you call for an end to renewable subsidies.

      • TruthinMaine

        Mr. Wallace, didn’t your parents teach you that it is not polite to call people names? That said, I will declare that I will fight ferociously against proliferation of industrial wind turbines that destroy the scenic areas of the most beautiful state in the eastern USA. But economics and public policy have always been the focus of my criticism of high cost/low production wind generation.

        Mr. Wallace, you are wrong about energy subsidies as they
        relate to electricity production. The wind industry would not exist without all the subsidies, tax breaks, and mandates, but energy dense sources would continue without any of these. I would prefer the government get completely out of any manipulation of any source of energy.

        Wind is such a feckless source of electricity, that it requires far
        greater subsidies than any other source of electricity per Megawatt Hour. In July 2011, the USEIA published results
        for 2010 for subsidies per MWH (direct, tax, R & D, and electricity support). The subsidy per MWH is $52.43 for wind; the
        next highest is $2.78 for nuclear, then 84 cents for hydro, 64 cents for coal,and 63 cents for natural gas.

        Support for wind is bad economics, based on poor science, mandated by bad public policy caused by lobbyists influencing politicians pandering to be “green” rather than making sound decisions based on economics.

        • Bob_Wallace

          I was taught to call ‘em as I see ‘em. Am I’m tired of you whiny Mainers complaining about paying a few extra pennies a month for your electricity in order to help get fossil fuels from killing our planet.

          And I’m tired of people who complain about the small amount of taxpayer support that has gone to wind and solar while saying nothing about the massive amount of support given to nuclear and fossil fuels.

          The only reason wind and solar are now receiving more subsidies than other new generation is because we’re installing wind and solar. If there were any new nuclear plants coming on line they would be receiving far more subsidies than wind and solar.

          Actually that will be happening if the new Vogtle reactors ever fire up.

          By supporting wind with taxpayer money we have brought the cost of wind-electricity from $0.38/kWh to $0.05/kWh over the last 30 years. Wind is now one of our cheapest two ways to bring new generation to the grid. And as natural gas prices rise wind will be the cheapest.

          You don’t even begin to understand the economics. And you don’t understand how grids operate.

          Why in the world would you support the two most expensive sources of electricity, coal and nuclear, over the cheapest and best for the planet?

          • TruthinMaine

            Since you obviously are a closed minded zealot who does not understand in any way shape or manner how grids operate and fail to understand economics, which I do from both my academic background and the experts with whom I consult, and since you are a belligerent sort, I bid you good bye in this way: Shove a wind turbine up your arse, as that is the only place wind turbines belong!

        • Mike White

          Hardly truth from this guy from Maine. He continuously follows news regarding renewable energy and always misrepresents reality. People who are unaware of the progress made in efficiency and the dropping costs of renewables may fall for the nonsense coming from Mr. Truth.

        • Mike White

          I am also a Mainer and have come around to the point where mountain top industrial wind in Maine dose not sound like a great idea, The problem with your arguments is that you discredit wind as a viable energy source. That flies in the face of facts that clearly show wind produced electricity is now economically viable.

          • Boydnar

            The thing about “TruthinMaine” is that, on the topic of wind power, he is stuck in the 1980’s, just like most of my redneck buddies. The human animal is fundamentally an emotional being, and once an individual has taken an emotional “set” on a subject, it’s dern near impossible to pry him off of it — facts be damned. In contrast, I try, as best I can, to live by the attitude expressed by Abraham Lincoln in his open letter to Horace Greeley, to wit: . . . and I will adopt new views just as soon as they are shown to be true views.”

  • Indiana

    I have done a lot of research. I have not seen a project with greater than 35% NCF and that is in Midwest. The rotor size example is nonsense. The project developer with best information available will put the most viable technical solution and once in place it will not change. Can you provide a example of an on-land project that operates at greater than 35% NCF?

    • Bob_Wallace

      Believe it or not, we’re still working on this.

      Zach was really ill for a week or so and when he got back on his feet he found that his contact at AWEA had left for a different job. Request is in but no one has picked up on it yet.

      I’ve put in a request to the EIA but have heard nothing back.

      I’m not sure we’ll be able to get you a “this turbine, this year” answer. Wind farms are private businesses and private businesses generally do not make their business details public.

      Statistics are collected by the EIA, aggregated, and summaries released. But I can’t find the details or raw data on line. You can see US onshore wind farm capacity summary statistics here…

      http://en.openei.org/apps/TCDB/

      Median capacity for onshore wind farms is 38%. half of all US onshore wind farms operate at greater than 35% NCF. The top 25% of wind farms report 42.86% or better annual capacity and the top performer returned a 50.4% performance. The name of that top performer? Might not be able to determine that.

  • Average Joe

    Another distressing example of the divisiveness that undermines any hopes of having a civil dialogue on these issues. Anyone who disagrees with you is a “hater?” It must be nice living in such a simple world…

    • http://zacharyshahan.com/ Zachary Shahan

      “hater” is a playful term. but hey, feel free to drop into the comments and start a divisive conversation. ;) :D

  • Pingback: Wind beats natural gas to become top source of new electricity capacity for 2012 | Trillion Fund® | Blog

  • Paul Lindsey

    Where is this “50% cf” wind farm? Where are the published production numbers? Are they averaged over an entire year, in order to mask the inherent variabliity?

    The only place where the general public can see real US wind power data is at the BPA’s website. Not only can you see the 7-day rolling graphs, but you can download the history at 5 minute increments for each year, going back to 2007. I just downloaded and analyzed May 18 – Dec 18, 2012. (I chose May 18 as my starting point because BPA’s latest windfarm was reported “online” on May 17, so the total capacity over the analysis period was constant at 4,711 MW)

    For the May 18 – Dec 18 period, the average output was 1,194MW (25.3% cf), with a Std Dev of 1,198MW. (yuk) The highest output in any 5-minute period was 4,365MW (92.6% cf), and the lowest was 0 MW (for 519 data points). The Capacity Factor (cf) was 5% or less for 32% of the time,10% or less for 42% of the time, and 15% or less for 49% of the time. Only 8% of the time did the combined output exceed 70% of the rated 4,711 capacity.
    The only reason BPA’s wind installation works as a reliable source of power is because of the BPA’s hydro resources. Everywhere else in the US, we’re “chasing the wind” using quick-starting OCGT’s or running other conventional power plants inefficiently at less-than-full-load conditions and then ramping them up & down. And when the wind isn’t blowing (and/or teh sun isn’t shining), enough fossil, hydro and nuclear power plants have to be on the line ready to supply the load.

    • Bob_Wallace

      Well, of course output is averaged over a year to determine output capacity. That is the definition of output capacity. Output/time.

      And, you are right. Wind is a variable input. Wind’s saving grace is that it is very abundant and cheap to convert into electricity. The fact that you can see that hydro is a fill-in for when the wind is not blowing shows promise.

      Give this paper a read. It shows how the largest wholesale grid in the world could be run with no inputs except wind and solar along with a tiny (0.1%) bit of natural gas. And the price of electricity would be about what we pay today.

      * https://docs.google.com/file/d/1NrBZJejkUTRYJv5YE__kBFuecdDL2pDTvKLyBjfCPr_8yR7eCTDhLGm8oEPo/edit *

      BTW, did you realize that the output capacity for coal plants is about 85%. About 15% they produce zero electricity and we work around that extreme ” inherent variability”

      • Paul Lindsey

        I’ll look at the link …

        Your coal example is not analagous. You have to ask why the coal plants are not running 15% of the time. I believe that the answer is required maintenance, just like nuclear plants are offline 8-10% of the year on average (not including situations like SONGS, Ft Calhoun or Crystal River 3). Planned & scheduled maintenance is not “inherent variability. I plotted half of the data I cited above. (I wanted to plot it all, but Excel limited me to 32,000 data points per series.) The result looks like a seismograph pen output during an earthquake.

        • Bob_Wallace

          Yes, the major reason why nuclear and coal plants go down is for maintenance (and refueling in the case of nuclear). They also break. They also get knocked down by earthquakes, floods and heat waves. But that is not the point.

          We have no 100%. always on, totally dependable sources of electricity. We have always designed our grids to deal with the uncertainty of supply and constantly changing demand.

          Going forward we will use less and less coal. We also are likely have less and less nuclear on the grid. There are no remaining large rivers to dam in order to bring massive amounts of hydo to the grid. Natural gas is a) not unlimited and b) contributes to climate change.

          Our choice? Back to the cave with our candles or figure out how to run an affordable grid with the main inputs being “variable” wind, solar, tidal and wave along with some dispatchable biogas and hydro and some almost-always on geothermal and biomass.

          Take a little time. Read the Budischak paper. Think of it as a ‘worst case’ analysis. The largest wholesale grid in the world run on nothing but wind and solar. And a tiny bit of NG.

          Electricity, all the grid wanted for about what we now pay.

          Then flesh out the worst case. Add in some hydro, tidal, geothermal, remaining nuclear, etc. Do some power swapping with adjacent grids. Include some dispatchable load. Invent more efficient solar panels, cheaper wind turbines and cheaper storage batteries.

          Now the grid gets all the power it wants for less than what we now pay for electricity.

  • MSF Wisc.

    The Berry Burn windfarm just kicked off construction and will average 31%.

  • Bob_Wallace

    JayTee – you commented –

    “By the way, the OECD says system costs (primarily transport) for onshore wind are roughly 13 x higher than for dispatchable technologies.

    Google “system effects in low carbon electricity systems””

    I did. Looks like you wrote 13x when you should have written 1/3x.

    Analysing data from six OECD/NEA countries, the study finds that including the system costs of variable renewables at the level of the electricity grid increases the total costs of electricity supply by up to one-third, depending on technology, country and penetration levels.”

    http://www.power-eng.com/news/2012/11/29/oecd-nuclear-energy-and-renewables-system-effects-in-low-carbon-electricity-systems.html

    Yes, we all realize that transmission costs are not added to some LCOE calculations and that increases cost to the grid. Just like the health problem costs of coal and taxpayer provided liability insurance for nuclear are not included. Coal and nuclear also have transmission costs. Perhaps not as high as wind, but still significant.

    IIRC, a sizable hunk of a bid reactor at Ontario was transmission costs.

    LCOE is simply one measurement that must be used when deciding to build new generation.

    Now, this thread is over 100 comments long. Please do not post to it any longer, it’s just too hard to wade through as it is. And your concerns have been addressed multiple times.

  • JayTee

    Looks like the University of Delaware says renewables will be competitive by 2030 (health effects included).

    That will be a great day for the world as our dependence on coal and gas will begin to decline.

    http://www.labmanager.com/?articles.view/articleNo/33645/title/Wind–Solar-Power-Paired-with-Storage-Could-be-Cost-Effective-way-to-Power-Grid/

    • Bob_Wallace

      Renewables are already competitive with coal, cheaper than coal, if you include health costs. Wind is cheaper than natural gas.

      If you are willing to include the value of less climate change then fossil fuels are too expensive to consider.

      The study you link is addressing a different issue. It’s showing that we could have a 90% to 99.9% renewable-sourced grid by 2030 using today’s technology. And our cost for electricity would be about what we pay today, all-in pricing.

      The great thing about that study is that it is based on four years of actual minute by minute data from the largest commercial grid in the world. One that serves 1/5th of the US, 60 million people.

      Then, if you consider that inventions that we’ll likely make during the next 20 years, you can see that this is worst case analysis. Most likely things will turn out even better.

  • Stephen

    You want to check out
    http://www.ref.org.uk/roc-generators/index.php?start=400&order=RollingLF&dir=desc
    for the UK, there are only 2 wind farms
    producing just over 50%, a few in the 40% range and few more in the 30% and the
    majority in the 20%…..

    The wind generally blows when demand is low, where we pay a consent amount
    to get the operator to turn them off…

    With no ROC, no wind farms would be built as it would be uneconomically
    viable

    • Bob_Wallace

      That’s an interesting chart. Yes, it does show that the wind does not blow all the time.

      It also shows that you have other renewable energy inputs such as landfill gas and hydro which are dispatchable and can be used to fill in for when the wind is not blowing. That’s how the future grid will work.

      Your onshore wind may only blow at night, but that has value. When you finally shut down your coal plants that nighttime wind input will be valuable because it will let you save other sources for use at other times.
      Obviously the UK doesn’t have great onshore wind potential. That’s why you are going to be tapping your enormous offshore potential. But the onshore you do have will add to the mix.

      • JayTee

        Redundant generation? Doesn’t that detract from the argument that wind power is cheap? If it has to be backed up you have to factor in those costs. You don’t have to back up fossil fuel plants.

        • Bob_Wallace

          We certainly do have to back up fossil fuel and nuclear plants. They do not run 24/365, coal averages about 85% and nuclear about 90%. Some form of generation has to fill in the other times.

          Redundancy is built into the system. We have gas plants that might run only a few days a year.

          Grid operators constantly work to balance supply and demand with generation coming and going and demand changing from minute to minute.

          The issue is which source is the least expensive. You use that and then turn to whatever the next cheapest might be. Wind, when available, lets the grid avoid pay higher priced producers.

          Right now wind and natural gas are the cheapest new generation. You wouldn’t go wrong building a lot of wind farms and gas plants were you adding new generation to the grid. Natural gas is cheap to build but fuel costs. Use wind when available and fill in with gas. That can let you run more than half the time with no fuel costs.

          Later we should be able to replace the gas plants with storage.

          • JayTee

            We don’t backup fossil nearly 100% because they are down for scheduled maintenance or due to demand fluctuations.

            Wind may be down at peak times. Therefore it requires much higher redundancy.

          • Bob_Wallace

            Wind rarely goes 100% down. Individual wind farms might not be producing but the odds are very high that wind farms not that far away are producing. Think about how storms and other weather systems move across the land. And give this paper a read….

            http://www.stanford.edu/group/efmh/winds/aj07_jamc.pdf

            Wind is more variable than fossil fuel generation, but we can’t afford to keep burning fossil fuels. That must stop and stop soon.

            Our cheapest ways to produce electricity are wind and (soon will be) solar. Both are variable. Our job is to figure out the best way to provide when the Sun isn’t shining and wind not blowing.

          • JayTee

            Bob…even if you’re talking about backing up with wind …you’re still talking about redundancy.

            Think of it this way…

            To guarantee 100 MW of electricity at 3:00 pm on August 10th….you either need to build exactly one 100 MW natural gas plant

            …or how many 100 MW wind farms.

            I’m not saying we shouldn’t get off fossils. I’m merely saying the costs of wind and solar are severely understated.

          • Bob_Wallace

            I suppose it depends on how you wish to spin it.

            Right now we have a large amount of dispatchable generation. Around 30% natural gas, 8% hydro, some storage, and 36% coal which is”slow-dispatchable”. We could mothball coal and use it for those very few times when wind is very low for a number of days.

            Wind is cheaper than coal and natural gas. Build wind, park coal and gas and save money. Solar is cheaper than coal and will be cheaper than gas.
            We already have redundancy. This is not a new required cost, it’s a savings by using it less.

          • JayTee

            Those are peaking plants for high demand times. No matter how you look at it…wind is far, far less reliable than fossil and isn’t correlated with demand.. It requires much greater backup to meet peak, and therefore the costs are being misrepresented.

          • Bob_Wallace

            Wind costs what it costs. Solar costs what it costs. Coal costs what it costs.

            Some power is more valuable to utilities at some times because it best meets grid needs or because it is dispatchable. Neither of those change what the power costs, it determines which is purchased.

            The costs are not being misrepresented. You are trying to force operational costs back on to generation.

          • JayTee

            If that’s true then please ignore pollution. If the cost of building redundant generation and 400 miles of transmission (each with environmental implications) can be ignored then so can sulfur and CO2.

          • Bob_Wallace

            What I’m about to ignore is you.

          • http://zacharyshahan.com/ Zachary Shahan

            Nope. A 100 MW natural gas plant also needs to be backed up. That’s the fundamental error here.

          • Boydnar

            Nobody’s understating anything, JayTee. All of the costs of wind power being cited here include the fact that a name-plate rated 100 MW farm will, on average, produce roughly 40 MW of juice. No one is hiding anything or failing to include anything.
            DO YOU UNDERSTAND?
            When a 100 MW farm produces 40 to 50 MW on average, the cost of that 40 to 50 MW of power is determined by taking the total of capital costs and all other costs of the farm and dividing the total by 40 to 50 MW’s — NOT by the name-plate rating of 100 MW. The cost of the power generated is based — IS ALWAYS BASED — on the ACTUAL POWER GENERATED, not on the name-plate rating. We ALL know that and that’s how the ENTIRE industry does it.
            DO YOU UNDERSTAND???
            What you’re doing here is implying that the cost of 5cents/kwh quoted here is based on the NAME-PLATE RATING — but then in reality the wingens produce only the capacity factor portion of that rating, thus making the 5cent cost statistic false. But that’s NOT what the industry is doing . . . and I think you know it.
            We’re all damn good at math, JayTee, This is very simple and we’re not hiding anything or lying. Nothing is being misrepresented here except what you misrepresent.

          • Bob_Wallace

            Put down the allcaps key and back away, please….

            JayTee is wrong about the cost of wind and solar.

            Apply a common sense test, Jay. If wind costs well more than 4c/kWh how could a wind farm stay in business selling a 20 year PPA for 4 cents?

            (I’m ignoring the 1.15c/kWh subsidy.)

            BTW, Jay, do you know that natural gas plants run only about 25% of the time (have a CF of about 25%). Just a bit more than solar panels produce but a lot less than the CF of wind turbines.

            You’re partly right about this part “To guarantee 100 MW of electricity at 3:00 pm on August 10th….you either need to build exactly one 100 MW natural gas plant”. There are other ways of insuring that 100 MW will be there. For example we could stick some wind or solar energy into storage or use dispatchable hydro.

            But that’s not how power is priced. It’s priced by the actual “plant” cost/output.

            Some generators will get paid more at times because they are available when less expensive generators aren’t. NG peaking plants can earn very high prices simply because the grid is desperate and they’re all that’s available.

            Storage is starting to take over for NG peakers. There’s enough money being paid for peaking power to make batteries competitive at their current price.

          • Boydnar

            The caps button? Didn’t use it that much. Would rather use italics, to emphasized certain words as I would if I were speaking, but italics aren’t available here.
            I was mostly addressing the issue that everyone else is tiptoeing around, and that’s a plain unwillingness on the part of wind detractors to have an intellectually honest discussion of the merits and viability of wind power. I have several friends who do the exact same thing that JayTee is doing — dismiss wind power out-of-hand with a head-shaking refusal to

          • Bob_Wallace

            yada, yada, yada.

            Impress us with the strength of your argument. Not with your ability to located the allcaps key.

          • Boydnar

            Or just don’t read my posts. I’m not interested in your whining about something trivial when basically we’re on the same side of the argument — which is not trivial.

          • Bob_Wallace

            (Here’s a hint. I’m the mod. This site doesn’t like shouters, regardless or whether we agree with them or not. It’s part of attempting to run an orderly house.)

          • Boydnar

            Shouting, Bob, is when a person puts the capslock on and leaves it on. I use it generally for a word or a few words, which isn’t shouting — and, as I said, I use it for emphasis as I would if I were speaking. I’ve already shown that I am perfectly happy to greatly reduce my caps use if you’re that sensitive about it. Make italics available?

          • Bob_Wallace

            I don’t do the programming.

          • Calamity_Jean

            May I respectfully suggest that you keep a copy of my link for future reference.

            https://help.disqus.com/customer/portal/articles/466253-what-html-tags-are-allowed-within-comments-

          • Bob_Wallace

            It’s on the site comment policy page.

            http://cleantechnica.com/cleantechnica-comment-policy/

          • Calamity_Jean

            “…italics aren’t available here.” Yes they are, and so is underline and bold. Go here for the codes: https://help.disqus.com/customer/portal/articles/466253-what-html-tags-are-allowed-within-comments-

            You’re welcome.

          • Boydnar

            Thanks, Calamity.

          • Calamity_Jean

            My pleasure. Knowledge is one of the few things that a person can give away and still keep.

          • http://zacharyshahan.com/ Zachary Shahan

            As noted above: When a large fossil fuel or nuclear plant goes down, a ton of power is going off the grid at one time and requires a lot more to be backed up than one wind farm in a non-windy spot.

          • Bob_Wallace

            A year or two back there was an earthquake on the East Coast and two nuclear reactors in Virginia went down for a few months.

            It was necessary to have sufficient backup to ride out that problem or a significant portion of the East Coast would have gone dark.

            San Onofre is down right now in SoCal.

            Chrystal River is down.

            Reactors have been shut down in the hottest part of the summer when demand is the very highest. They are shut down because there’s no water to cool them.

            All of those reactors went missing for both off-peak and peak hours.

            Does the “true cost” of reactor produced electricity include the cost of having redundant generation in your book?

        • http://zacharyshahan.com/ Zachary Shahan

          Fossil fuel plants also need backed up. They sometimes go down. And one important thing to note about them is that if one goes down, a ton of power is going off the grid at one time and requires a lot more to be backed up than one wind farm in a non-windy spot.

          • JayTee

            Wind goes down far more frequently than fossil. Plus those downtimes are unscheduled. Rarely the case for fossil fuels.

          • Bob_Wallace

            So what?

            Fossil fuels are killing the planet. At least our ability to lead the sort of lives we would like to live on it.

            Wind and solar are producing affordable power and without environmental damage.

            Yes, they are variable. That simply means that we will have to find how to use them as replacements for fossil fuels, they are not direct plug-ins.
            The future grid will be dependable, environmentally benign, and cheaper than today’s grid.

          • Calamity_Jean

            “Plus those downtimes are unscheduled.”

            Not totally. Short-term weather prediction is good enough that a wind farm can anticipate going down (or powering up) within the next two or three hours, and warn their (natural gas or other) backup to prepare for it.

          • Bob_Wallace

            Plus weather predictions are fairly good out a few days. Utility managers have a decent idea how much wind and sunshine they’ll have to work with in advance.

    • http://zacharyshahan.com/ Zachary Shahan

      notably, as pointed out in the article above, 50% is for new wind turbines. even many 2012 wind farms wouldn’t have those yet — takes time to build a wind farm. thanks for the chart — interesting.

  • Jpscott78

    If you want to make your argument based on cost, use some type of metric in terms of $/MW. Production cost, construction cost, etc. Wind is no doubt cheaper, simply because its’ fuel costs are zero. But again, reliability is the issue and is too dependent on outside sources (weather). Base loaded generation of some type will always be needed.

    • Bob_Wallace

      $/MW is not very useful unless you also take capacity factor into consideration.  If you know $/MW and capacity then you can calculate $/MWh.  

      “Base loaded generation” of no type will not be needed.  All is needed is power supply to match power demand.

      We could have input from the Sun for 4.5 hours (average) per day paired with a big honkin’ amount of batteries and we’d have power when needed.  Now that’s not a very efficient way to power our grid, but it can be done.

      The grid of the future will almost certainly be large portions of variable wind and solar with infill from storage and dispatchable generation.

      • JayTee

        True..

        Your last statement belies the fact that wind and solar require redundant capacity. And thus, their costs are understated.

        • Bob_Wallace

          When we brought nuclear on the grid we had to build storage. A new nuclear plant that added to our capacity would require redundancy.

          Were we to increase our grid supply by 10% with gas we’d have to create backup.

          All generation needs backup/redundancy.

  • Jpscott78

    The capacity factor argument has nothing to do with cost. There are no dollar amounts associate with this metric at all. It boils down to reliability. How many of you want your electricity 50% of the time??

    • Bob_Wallace

      Sorry, Jp, that’s wrong.

      As capacity factor goes up, assuming turbine cost stays constant,  the price of electricity produced drops.

      50% capacity out of a same cost rig produces electricity for half the cost of a turbine delivering only 25% capacity.  It’s pretty simple math.

      And capacity factor is not a measurement of the amount of time the wind blows.  It’s simply measured output/”nameplate” capacity.

      Nameplate capacity is what would be realized if the turbine ran full speed 100% of the time.

      • JayTee

        What if most of that power is produced during off peak demand. Like at night. Or in winter? What matters most is how much is produced at 3:00 in August.

        Reliably.

        .

        • Bob_Wallace

          Install solar for daytime power. Point part of the panels toward the west or use tracking to make sure you’ve got power for 3PM in August.

          If you’ve got excess off-peak power then build storage. We built over 20GWs of pump-up storage to carry unneeded nuclear output to peak hours.
          Design your grid for your needs. Wind, solar and storage is likely to be our cheap route to a fossil fuel future. Biogas, biomass, tidal, hydro and geothermal will contribute but at this point aren’t likely to dominate. Wind and solar are more available and will likely (along with the needed storage) be cheapest.

          • Boydnar

            Y’all are proceeding under a false assumption. The discussion is proceeding as though everyone accepts the assertion that the wind blows only at night. Here in Midland, TX, the frigging wind blows ALL THE TIME. I mean like 90% of the time! Look at a wind map, people. There’s plenty of area in the Midwest in which the wind blows DAY AND NIGHT. If we were to put up, say, 200,000 big wingens (my proprietary term, you may use it under license only) from Texas to North Dakota, we’d have plenty of wind electricity for air conditioners at 3:00pm in August.
            This whole discussion about having wind “only at night” is completely bogus and fraudulent.

    • Boydnar

      Jpscott said, “How many of you want your electricity 50% of the time??”

      Really, JP?

      Really???

      By asking that question you’ve shown that you either lack the raw intelligence to understand how wind power works in conjunction with other sources to meet demand . . . or you DO understand it and you’re just being willfully dishonest.

      If I need to explain this further then it’s the former.

  • Kalendjay

    Ya’all are hung up on CF and LCOE when average windspeed is the king of wind power viability. When windspeed doubles, power increases by the cube of the square root.

    By this account, North Dakota, not Texas should be the US’s chief windpower producer. Not only is the wind better, but Texas has for decades the least friendly state in terms of grid development and national grid integration. The Midwest has a long established grid psychology because of rural electric coops and coal development. A grid from Ontario to ND would have solved the issue of dumping in periods of excess power production: Since wind turbines were not staggered between these localities, Ontario is effectively subsidizing Midwest rates at a substantial loss.

    • Dave2020

      “Ya’all are hung up” Don’t include me Kalendjay. You are right – for both CF and LCOE, by FAR the most important factor is location, location, location. But even then, the wind is still VARIABLE!!!

      Here’s another reason why I say that reactionary enthusiasts for orthodox wind are wrong to erect their barriers to real progress. To be perfectly candid, you guys are a pain in the butt! We need to have energy storage and we need it NOW!

      http://www.bbc.co.uk/news/uk-wales-mid-wales-19051349

      Iolo ap Dafydd – BBC Wales environment correspondent, writes:-

      “It is contentious because of the countryside – there’s a strong feeling it will mean an industrialisation of this area.

      On the other hand, we’ve got the UK government and the Welsh government saying we need to have more renewable clean energy.

      That means, at the moment, onshore wind farms.”

      When you live on a small island these issues matter. Local environmentalists don’t give a toss about the LCOE of the wind turbines. Can you blame them?

      On the other hand, both governments are convinced we have no option but to lock our energy market into using a lot of unabated gas until at least 2045. This is an economic and environmetal disaster in the making. We desperately need off-shore renewables ASAP and we need adequate storage to go with it. The US could muddle along without, but why would you?

      There’s a smell of gas in the basement!

      http://alansenergyblog.wordpress.com/2012/07/30/theres-a-smell-of-gas-in-the-basement/

    • Bob_Wallace

      North Dakota and the rest of the windy Midwest will play a larger role once enough HVDC transmission lines are built to the east. The windy West (Wyoming, etc.) are likely to ship their power to the Pacific coast.

  • A guy

     “Clean energy haters love to talk about capacity factor because it’s
    clearly a metric wind, solar, and hydro don’t win at (though, geothermal
    and biopower actually do very well).”

    Even worse, most of the time they don’t even understand the metric and say things like: “wind turbines deliver electricity only 20% of the time”.

    • http://cleantechnica.com/ Zachary Shahan

      Good point. Should throw that in more.

      • Tomgraywind

        Yes, agreed.  I have seen even utilities make this very fundamental error.–Tom Gray, Consultant, American Wind Energy Association

        • http://twitter.com/Kompulsa Kompulsa

          Yes, the fraction of the time that they generate electricity is totally different from the average amount of electricity that they generate as a fraction of their generation capacity, which is capacity factor.

          They generate electricity most of the time.

  • Pingback: Wind Turbine Capacity: 50% is the New Normal « Climate Denial Crock of the Week

  • http://twitter.com/vetxcl T. Lester

    Yup. the more science and reality that can be used in the war of words, the better.

  • Dave2020

    I have to agree with what dbr2 says:-

    “I think the tone ‘clean energy haters’ is more polarizing than it needs to be.”

    But “the conclusions of the article” need to be qualified, as Bill woods has done.

    “Taken in isolation, capacity factor is an irrelevant statistic.” I’m afraid that’s true.

    The polarization we see with wind is the ‘haters’ cherry-picking bad statistics and the enthusiasts cherry-picking good statistics. That kind of debate has missed the crucial point.

    Ultimately, real progress depends upon addressing the real issue – variability. That is what I was trying to do in my first post here last December:-

    Clean Technica (http://s.tt/14Mwl)

    Your reply was very disappointing because you started by saying “nothing competes with the HAWTs we have”. The term “nothing” doesn’t allow much room for discussion does it? All I ask for is constructive criticism and I posted the invitation – You’ll find me here: davesmart@greenbee.net – because the devil’s in the detail and it’s difficult to cover the subject adequately on a comments thread.

    It doesn’t help the ‘green revolution’ when people let their enthusiasm cloud their judgement. Here is a level-headed look at the current situation, but I wish to contest what I see as a pessimistic conventional analysis and go beyond the state of the art..

    http://www.guardian.co.uk/environment/video/2012/jul/27/future-energy-video?intcmp=122

    I think the two shortcomings of off-shore wind – expensive and intermittent – can both be addressed with smart design. If that can be done – problem solved. No need for nuclear or fossil fuel generation, apart from some deep NG ‘back-up’.

    If the US learns from Europe’s mistakes, it could save you tens of billions of dollars on 500GW of marine renewables off the Atlantic coast. If you’re curious Zach, I will try AGAIN to explain in more detail. Please send the LBNL and NREL research to my inbox. 

    Taken in isolation, the LCOE of a wind turbine is misleading. The efficiency of delivering that electricity when and where it’s needed is equally, if not more important. Renewables + dispatchability is a marriage made in heaven. 

    I think energy storage before generator is a game changer. It’s a unique solution and turbine power capture is divorced from generator size. This concept promises a capacity factor more like 80%.

  • Bill_Woods

    What does “such machines can often hit 50% capacity factor” mean? Many hours per year? Many locations?

    Capacity factor is to a considerable extent a design choice: 
    Put a big rotor on a small generator; you’ll get a high CF but a low peak power, and a small amount of energy per year.
    Put a small rotor on a large generator; you’ll get a high peak power but a low CF, and a small amount of energy per year.
    The maximum energy production is going to be somewhere in between.

    • Bob_Wallace

      Come on Bill, you know exactly what 50% capacity factor means.

      “Capacity factor is the ratio of the actual energy produced in a given period, to the hypothetical maximum possible, i.e. running full time at rated power.”

      http://www.umass.edu/windenergy/publications/published/communityWindFactSheets/RERL_Fact_Sheet_2a_Capacity_Factor.pdf 

      Matching rotor size and generator size to prevalent conditions is what engineers do.  Previously wind turbines couldn’t hit 50%.  Now they can – right tech in the right place.  Technology moves forward….

      • Bill_Woods

        I don’t know what that qualifier, “often”, is doing in there. It seems to suggest something other than that a 2-MW turbine will produce 8766 MW-h per year.

        “Previously wind turbines couldn’t hit 50%.”

        Sure they could. If it made sense….

        If taken in isolation, capacity factor is an irrelevant statistic. A wind turbine with a 2 megawatt (MW) generator installed could be power limited to 1 MW; calling this a 1 MW machine, the capacity factor would go up from an average 30% to around 50%. The turbine however would deliver less energy, displace less carbon and have the same energy cost and environmental impact to build.

        http://www.bwea.com/ref/capacityfactors.html

        Another way of looking at the capacity factor paradox is to say, that to a certain extent you may have a choice between a relatively stable power output (close to the design limit of the generator) with a high capacity factor – or a high energy output (which will fluctuate) with a low capacity factor.

        http://wiki.windpower.org/index.php/Annual_energy_output

        • http://cleantechnica.com/ Zachary Shahan

          often was referring to the turbine.

          some turbines are better than others. the norm now seems to be the 50% ones that have popped onto the scene. but, of course, in some locations, those aren’t used.

          sorry for the ambiguity.

          • JayTee

            Hey Zach…I don’t know where to get the data.

            Where can we find a list of wind farms with associated capacity factors?

            .

    • Ross

      What is being claimed is that it isn’t purely about sticking big rotors on existing turbine technology in a suboptimal way simply to artificially boost the capacity factor.

      It is about improved technology, and better matching that technology to the prevalent wind conditions at sites.

      Here’s another quote from the BWEA link you give below.

      Wind turbine technology is improving with each new model produced, and tower heights are increasing, giving higher capacity factors than with smaller older machines on small towers.

      • Anne

         “Sticking a big rotor on … a suboptimal way .. artificially boost the capacity factor”

        You seem to be thinking they only do it for the PR value, that there is no good reason to do so. As if they don’t know what they’re doing and there is no thinking going on behind the scenes. The wind industry is mature and highly competitive, so there is little chance of that. They don’t do these things just for the bragging rights ;)

        As Ronald Brak pointed out below, wind influences electricity prices and they drop significantly under high wind conditions. Using a bigger rotor relative to the generator makes more sense when you say differently: using a smaller generator relative to the rotor. This saves money and only hurts production when electricity prices are low anyway.

        A second factor to consider is that technical progress enables the manufacturing of larger turbine blades at lower cost (for example by using carbon fiber). So the bigger rotor generates more electricity when prices are high (in low wind conditions), at a very low incremental cost.

        So there are very good economic reasons behind this development.

        • JayTee

          If the wind industry is mature and highly competitive then why is it still subsidized so heavily?

          • Bob_Wallace

            Wind is almost at the point at which it can stand on its own without subsidy, but critical infrastructure such as new turbine and blade factories are still being built.

            We could take the subsidies away from wind, but we aren’t going to take the subsidies away from fossil fuels and nuclear, they have too much political power. Why should we handicap wind?

            Finally, if we want to get off fossil fuels quickly, which is extremely important, it is in our best interest to artificially accelerate the transition. A small subsidy can mean that we build wind much faster than what would happen without those subsidies.

            No, finally, we need to remember that by subsidizing wind and getting more on line we are buying ourselves much cheaper electricity down the road. The cost of power (LCOE – levelized cost of electricity) is calculated on a 20 year loan/capital expense payoff. Our first generation wind turbines (Altamont Pass Wind Farm) are just now being replaced after 30 years. That means that they cranked out almost free power for 10 years. Current technology is better, I’ll bet we get at least 20 years of almost free electricity out of them.

            Fossil fuel and nuclear plants keep on requiring expensive fuel after their 20 year payoff. Wind and solar do not.

          • JayTee

            Name one large scale windfarm that has been or is being built in the U.S. or Europe without a government loan guarantee or subsidies.

          • Bob_Wallace

            Why?

            Name me one nuclear plant that doesn’t depend heavily on taxpayer funding.
            Name me one coal plant that pays its own health costs.

          • JayTee

            Bob, you don’t seem to understand that I am talking about the calculations that have been quoted in this article. I am NOT talking about the overall pros and cons of this type of energy.

            I understand the externalities.

            .

          • Bob_Wallace

            The article is about capacity factor. You’ve been asking questions about subsidies and backup generation.

            If you’ve got a capacity question it is not clear to me.

          • JayTee

            You must have read a different article.

            Much of the article above is about LCOE.

            An analysis of LCOE is disingenuous without discussing costs of backing up wind.

          • Bob_Wallace

            No.

            LCOE does not include backup power.

            Terms have meaning. You are attempting to redefine a commonly used term.
            LCOE is a calculation of the cost of generating electricity at the point of connection to a load or electricity grid. It includes the initial capital
            , discount rate , as well as the costs of continuous operation , fuel , and maintenance .

            http://en.wikipedia.org/wiki/Cost_of_electricity_by_source

            Cost of generating at the point of connection.

            Transmission is not included.

            Backup is not included.

            Very little of the article is about LCOE. Read it again.

          • JayTee

            I figured that if LCOE and “cheapest” are mentioned in two of the three takeaways at the end of an article..then the article is about those things.

            But you understand:

            1.
            Wind advocates are defining “cheap” too tightly.

            2. LCOE ignores factors (that should be much more easily included than pollution) that make it useless.

            Wind isn’t cheap. It may be good for the environment. But it isn’t cheap.

            Is a car cheap if it requires you to have two cars?

          • Bob_Wallace

            Does your definition of the cost of a car include the cost of a garage? How about the cost of a car elevator.

            Now, I think I’ve spent about enough time with you. LCOE has a meaning. You do not have permission to change it. Work with the term as the industry defines it.

            If you want to talk about transmission, time of production cost of backup, or any of a number of other issues concerning designing and operating the grid, fine. But please use words consistent with their common use.

            And keep a few basic concepts at hand. No generation source is 24/365. It is necessary to provide backup supply for all generation. All generation sources come with their own set of advantages and disadvantages.

            Finally, you may think that “wind advocates” are “defining “cheap” too tightly” but the fact is that wind on the grid is bringing down the overall cost of electricity.

          • JayTee

            If one car requires me to purchase a garage and another does not – then yes – that is a very important factor. Excellent example.

            I’m not trying to redefine it. I’ve pointed out how useless it is. It leaves out higher transmission and redundancy costs..

            Nice talking with you.

          • Bob_Wallace

            You’re right, JayTee. You get to define all terms. And you get to decide how they are used.

            Now, please enjoy your victory because day after tomorrow, on Monday morning, you have the task ahead of you of letting hundreds of millions of people who work in the energy field know that they can’t use LCOE in the same way ever again.

            There will be books to be rewritten, web sites to correct, so much work to do.

            From now on there will be a larger meaning for LCOE. It will include transmission costs, backup costs, storage costs, and perhaps the price of your lunch burger.

            There will be no need for transmission cost columns nor for backup cost columns. It will all be rolled into a new, larger definition of LCOE.
            And all those millions of people. The sound of them slapping their foreheads in wonderment of how wrong they’ve been….

            Now, get some rest. You’ve got a busy year ahead of yourself.

          • JayTee

            What is wrong with you? I’m just saying the measurement does a poor job of comparing energy sources. Nobody has posted a valid argument.

            You don’t need to get so uptight simply because wind power has higher transmission and backup costs than traditional sources.

            I think wind will eventually be competitive. But it isn’t there yet.

          • enoch1680

            JayTee cmin back at you; what is wrong with you? So many of the people who talk about free markets, subsidies and the like, are actually making a mockery of free markets. Once you take the externalities out of the equation you have distorted the market, you no longer have a free market. 10 years ago wind and solar were expensive. Now, in a real free market that internalizes things coal power would be in steep decline. It sounds like your point is that you want to make an honest comparison. So take your choice, either go with a real free market in which coal is a total has-been or go with a distorted market in which some support is included for renewables to make up for a portion of the market distortions. And please take a moment, catch your breath and make peace with what your agenda is and then be forthright about it – at least with yourself. http://solar.gwu.edu/index_files/Resources_files/epstein_full%20cost%20of%20coal.pdf

          • http://zacharyshahan.com/ Zachary Shahan

            Why would they build a wind farm without the help if the help is offered? Sorry, that’s purely nonsensical.

          • JayTee

            So if the tariff expires…how many will get built?

            All of these companies including 1 right here near where I live, have announced that they are dramatically cutting back their activities because of the expiration of the tariff.

          • Bob_Wallace

            One of the reasons that wind farm construction in the US may decrease if subsidies are not continued is because companies can take their operations to other countries and make more money there.

            That’s why much of the geothermal industry packed up and left Australia for Indonesia.

            Lower subsidies will lower profits. That causes less money to be invested. It’s rather simple business.

          • JayTee

            The cost of fuel for a nuclear plan is almost negligible.

            For wind you still have landowner royalties. Not expensive….but not “free” as you say.

          • Bob_Wallace

            According to an internal industry document from the Electric Utility Cost Group, for the period 2008 to 2010, maintenance and fuel costs for the one-fourth of the reactor fleet with the highest costs averaged $51.42 per megawatt hour.

            That is perilously close to wholesale electricity costs these days.

            http://www.nytimes.com/2012/10/24/business/energy-environment/economics-forcing-some-nuclear-plants-into-retirement.html?_r=1

            That puts the cost of nuclear in some paid off plants as high as electricity from a brand new wind farm. That’s why we’re starting to see paid off nuclear plants closing.

            I did not say “free”, but “almost free”.

            20% to 25% of the LCOE of wind is O&M. Land leases are a small percentage of that number.

          • http://zacharyshahan.com/ Zachary Shahan

            Why are the others still subsidized so heavily? (And after many decades of more subsidies.)

          • MorinMoss

            Because it’s up against the much larger, much more mature and even more heavily subsidized fossil fuel industries.

          • Bob_Wallace

            Wind has been only lightly subsidized if you compare it to coal, gas and especially nuclear.

            Since you wrote this things have changed.

            The wind industry has announced that they are close to needing no more subsidies. They requested last December that Congress give them multiple year funding which would stay at 2012 levels for a couple of years and then fade down to zero by 2018.

            That’s onshore wind. Offshore wind will need some years of assistance before its ready to stand on its own feet. There are docks and specialized ships to build, workers to train. Once the basic infrastructure is in place offshore will be self-supporting.

            The solar industry is starting to say that it’s about time to end solar subsidies. I’ve heard no one suggest that subsidies need be extended past 2017 when the current program expires. Some are even arguing that pulling the subsidies earlier would help bring system prices down even faster.

            We see no signs of fossil fuels and nuclear being willing to give up their tax dollar supports.

      • Anne

         Hmmm, re-reading your comment, it seems you were actually trying to say something different. Consider my reply then to Bill Woods.

        • Ross

          Yes, your second reading is correct. I didn’t mean to suggest anyone actually does that.

    • http://twitter.com/vetxcl T. Lester

      ” What does “such machines can often hit 50% capacity factor” mean? ” 

      What do you mean by “mean?” :)

    • Dutchy

      In the Netherlands you have the sad case that you can maximise your subsidy if you artificially lower capacity factor. As a consequence the Dutch wind turbines are not very efficient and give the wind opponents a handy weapon.

    • http://twitter.com/Kompulsa Kompulsa

      I”m not certain about some of what you said. The smaller the generator is, the less it will generate. Slow wind speeds + a large generator = more power than those same slow winds + a small generator.

      It is important to factor in the type of generator, whether it is a low-RPM design or what.

      • Bill_Woods

        Consider a (made up) example. Over the course of a year, the wind blowing through a rotor in a particular place could potentially generate

        2000 hr * 1 MW = 2 GW-h
        2000 hr * 2 MW = 4 GW-h
        2000 hr * 4 MW = 8 GW-h
        1000 hr * 8 MW = 8 GW-h

        The other 1760 hours of the year, the wind is either too weak or too strong for the turbine to operate. The amount of actual electricity produced would depend on the capacity of the generator connected to the rotor:

        1 MW: 2*1 + 2*1 + 2*1 + 1*1 = 7 GW-h ; / 8.8 GW-h = 79% CF
        3 MW: 2*1 + 2*2 + 2*3 + 1*3 = 15 GW-h ; / 26.4 GW-h = 57% CF
        5 MW: 2*1 + 2*2 + 2*4 + 1*5 = 19 GW-h ; / 44 GW-h = 43% CF
        8 MW: 2*1 + 2*2 + 2*4 + 1*8 = 22 GW-h ; / 70 GW-h = 31% CF

        The smallest generator produces much less energy than the largest one, but it spends much more time operating at its peak capacity, so it has a much higher capacity factor. Which size is the more cost-effective depends on the costs of the options.

        • enoch1680

          You are right that CF alone is not anything to write home about. Arbitrarily tweaking engineering parameters to improve the CF is not helpful in the grand scheme of things. However, improving CF WHILE ALSO improving LCOE is a very important and significant step. It is hard for me to understand why people seem to be disputing that in these threads.

  • dbr2

    Zachary,

    I discovered CleanTechnica a couple of months ago, and I have been enjoying reading the articles.

    I agree with the conclusions of the article but I think the tone “clean energy haters” is more polarizing than it needs to be.

    I think there are 2 competing, good values in energy production:

    Low cost – The availability of cheap power has enabled enormous improvement in our quality of life and economic growth.

    Low environmental impact – health , climate change , sustainability.

    I think the policy question comes down to how we balance the two.  Through clean energy mandates, tax credits, etc.  I don’t think I have ever met anyone who hates solar panels – I think it is the mandates / tax credits.

    The articles on your site (including this one) give me hope that by extending some relatively modest subsides for clean energy, we will get to the point that energy can be both cheap and clean

    • http://cleantechnica.com/ Zachary Shahan

      hey, thanks. it was really more of a joke than anything. certainly, none of our regular readers are haters. and a very small % of the population is. but there actually are people who seem to hate solar panels and wind turbines (wind turbines more so). i don;t understand it, but i;m sure of it, after reading through thousands upon thousands of comments on here. :D
      the people who dislike subsidies for clean energy are another bunch (of course, with some overlapping). and they’re concerns certainly do require some other points/articles — some coming this week :D.

    • Tomgraywind

      I kind of like “wind detractors” myself, though in Vermont, where I live, the crazy rhetoric is definitely nearing the borderline of hatred. I think it is partly just spillover from the overall political dialogue in the U.S., which has gotten much more vitriolic in recent years.–Tom Gray, consultant, American Wind Energy Association

  • mohan

    At the outset, i am not a wind energy hater, but a renewable energy consultant working in india since 2001. The point of debate was that of spokesperson of greenco was claiming a capacity factor of 30% for maharashtra and 50% for newer machines, which i think is amazing (read as unbelievable) in indian wind conditions. Again the capacity factor is misleading, for a typical high wind month / day you can get a higher capacity factor in indian conditions too, but that would be misleading. The industry standard when we say capacity factor is on annual basis and not on the basis of select few days or a particular high wind month. I have been promoting wind since years and i would be very happy if the purported capacity factors are realised on annualized basis. That day is not far, but it is definitely there not at present in indian conditions!

    • Bob_Wallace

      Perhaps (not knowing India’s wind conditions) the turbines installed to date are not appropriate for the wind found at those sites.

      Up until recently it’s been something of a “one size fits all”.  Now at least one company is designing turbines for places which have lots of windy hours, but not as high velocity winds.

      Is it the case that India has some very windy months and some months with almost no wind?  Or that the turbines used are not optimized for the normal wind?

      Should point out – the EIA capacity numbers apply only to the US.

      • mohan

         Hi Bob
        In India almost 60% of the annual wind energy generation takes place in four months and balance 40% in the balance 8 months. Since it has a good rain fall in most parts of the country the generation is higher during the monsoon periods, when the winds are good and air is denser with moisture.

        • Bob_Wallace

          Interesting.   How about offshore?

          Solar may be a better solution for India.  Plenty sunshine from my experience.

          I haven’t been in India during the monsoon.  Is there a lot of cloud cover during those weeks?  Might a combination of wind and solar work well, each having their ‘best season’?

          • http://cleantechnica.com/ Zachary Shahan

            yeah, some interesting points/thoughts here. India does seem to face very extreme changes throughout the year. Wind might not be so ideal. That said, one recent report we wrote about increased India’s wind energy potential dramatically. India’s a big country — I’m sure it depends on the region.
            But the country has some of the best solar potential. I think it’s recent shift to a stronger focus on solar is a good call.

          • Tomgraywind

            Umm, except that the cost of wind in parts of India has dropped below the cost of coal: http://cleantechnica.com/2012/07/26/in-parts-of-india-wind-energy-proving-cheaper-than-coal/ – Tom Gray, consultant, American Wind Energy Association

          • John Storm

            ….except that cost comparison between dispatchable generation and intermittent generation is meaningless:

            MIT’s Schmalensee:

            “….It follows that discussions of “grid
            parity” based on comparisons of the levelized cost per kilowatt-hour (kwh) of electric energy (generally abbreviated LCOE) from wind or solar power with average wholesale prices have little economic or commercial meaning.”[1]

          • Bob_Wallace

            That’s a pile of horse hockey.

            Grid parity is grid parity. The issue is whether the utility doing the purchasing can incorporate solar and wind at an affordable price. If there is ample flexibility then price rules.

            You advocate for nuclear energy. Nuclear has the same sort of issue. It must have a late night market and most grids have no under-served demand. If nuclear could be produced as cheaply as wind and solar there would still be an incorporation problem.

            BTW, new nuclear is very much too expensive to be anywhere close to grid parity.

  • http://cleantechnica.com/ Zachary Shahan

    Thanks for the comments:

    My main extra points:

    1) wind is now available in a lot more places (places with lower wind speeds)
    2) this also expands the times at which wind is available, making it more useful wind electricity is actually needed
    think there was something else… but maybe not. will come back here if i think of it. :D

    • John Storm

      “… wind is now available in a lot more places (places with lower wind speeds)”

      But at far higher prices. Note the extreme range of PPA prices that are highly dependent upon which part of the US the project is located:

      http://emp.lbl.gov/sites/all/files/lbnl-6356e.pdf

      • Bob_Wallace

        The average selling price for wind is 4c/kWh.

      • Bob_Wallace

        We see what you did here.

        You cherry-picked some data from 2010 when wind prices were high due to a temporary increase in turbine prices due to demand exceeding supply.

        An honest person would not have done that.

  • http://ronaldbrak.blogspot.com.au/ Ronald Brak

    In many places the price of electricity drops when there are strong winds, so it makes sense to build new wind turbines to take more advantage of lower wind speeds than higher wind speeds.  This makes wind turbines cheaper to build and ups their capacity factor and makes them more economical, even though they may generate fewer kilowatt-hours in total than a similar sized wind turbine at the same site with a larger generator.

    • Dot

      I do not know about “cheaper”, since wind blows far enough from the cities, where thr major consumption occurs. You have to add power lines, deal with a number of green activists, and ensure continuous power supply. Once everything is accounted for, it is not that attractive.

      • Bob_Wallace

        LCOE (levelized cost of energy) includes all that stuff.

        Wind is cheap.  Median price $0.05/kWh.  Minimum price $0.04/kWh.

        http://en.openei.org/apps/TCDB/ 

        • JayTee

          Including the cost of the transmission lines? As another poster mentioned above – wind farms are built great distances outside of cities.

          • Bob_Wallace

            The one study I’ve seen finds that transmission cost for wind are about two cents per kWh. All generation has transmission costs, nuclear and natural gas were priced at one cent per.

            (Lost the link to that data, sorry.)

            Also, it’s worth remembering that LCOE does not include all costs (including transmission). The health effects of coal,
            the environmental damage of coal, natural gas and nuclear, and taxpayer provided insurance for nuclear are not calculated into the LCOE number.

          • JayTee

            I understand that polution isn’t factored in as it’s been mentioned several times.

            Wind is built further from the grid than any other form. Lengthy, nNew transmission is almost always required. If it’s so cheap, why are we still subsidizing it? I’m not anti-wind as I live in Kansas (of all places) I just think there is a lot of intentional misinformation about the industry.

          • http://zacharyshahan.com/ Zachary Shahan

            As stated above, why are other forms of power still subsidized? They are, and to a much greater tune, and have been for a much longer period of time.

          • JayTee

            Right. We should end those also. But fossils enjoy miniscule subsidies per BTU compared to wind.

          • Bob_Wallace

            Bull. Absolute bull.

            We pay over $0.15/kWh to cover the health and environmental damage for coal.

          • JayTee

            We’re talking about subsidies Bob. Not externalities.

          • Bob_Wallace

            It doesn’t matter how the money gets out of your pocket, via utility bills, taxes or health insurance premiums. The end result is that money is extracted from your pocket.

            It makes huge sense to give wind a couple pennies per kWh to help it get up and going if it saves us 15 or more pennies per kWh by allowing us to get off coal.

            That’s simple arithmetic….

          • JayTee

            But Bob. He asked why fossil fuels are subsidised.
            I understand coal costs us in other ways…but you are trying to double count.

            By the way, the OECD says system costs (primarily transport) for onshore wind are roughly 13 x higher than for dispatchable technologies.

            Google “system effects in low carbon electricity systems”

          • Bob_Wallace

            It’s kind of hard to see how acknowledging both the direct and indirect costs of a technology are “double counting”.

            Offshore wind will start expensive but is expected to drop rapidly. Europe has already done the heavy lifting. We’ll have to build our own manufacturing, installation and transmission infrastructure but other people have spent the “how to” money.

            Offshore will pay for its higher capex because the offshore wind blows longer and more steadily.

            The EIA projects the cost of offshore wind to be close to that of onshore wind in 20 years. And since offshore tends to blow more during the day than onshore and is closer to the heavily populated eastern and western seaboards it will have higher value.

          • JayTee

            1. I didn’t mention offshore.

            2. I’m only saying you can’t say fossil fuels are heavily subsidised and talk about how weddon’t pay for their externalities. It has to be one or the other because fossil fuels don’t receive large direct subsidies. If you say they do…then name the subsidies or provide a link.

          • Bob_Wallace
          • JayTee

            I said onsshore.

            It’s double counting because you claim wind is competitive plus better for the environment. Then when I bring up the subsidies you say we need them because wind is Better for the environment.

          • JayTee

            Very little coal is being built in the u.s.

            My point isn’t that wind isn’t a good idea if you account for externalities.

            The point of this article and most of the posters is that wind is competitive.

            It isn’t competitive unless you attach an estimate for externalities – which is fairly arbitrary. Necessary- but arbitrary.

          • Bob_Wallace

            How can something be “necessary” but “arbitrary”?

            Arbitrary – def – Based on random choice or personal whim, rather than any reason or system.

            If it’s necessary then personal whim is off the table.

            Nuclear and coal are only competitive if 1) we are talking about older, paid off plants and 2) we ignore the external costs we pay.

            As far as wind being competitive. The LCOE of wind is (median) 5 cents. Transmission adds in a couple of pennies.

            The only cheaper generation to build is natural gas and it won’t stay cheap. The plants you build today will need tomorrow’s more expensive fuel.
            And 20 years down the road when the wind and gas turbines are paid off gas will still have a fuel cost to service. Wind will not.

            Very little coal is being built. That’s because new coal, even without including external costs, is too expensive.

            Now, how many times to you intend to beat on this dead horse?

          • John Storm

            “As far as wind being competitive. The LCOE of wind is (median) 5 cents. Transmission adds in a couple of pennies. ”

            Yet in many places in the US wind costs far more than that. IA wind sells for $30.00 yet in MI the fleet capacity weighted average is $80.00. Add the PTC back and you are at an LCOE of well over $100.00. And that is before adding the cost of wind dedicated transmission.

          • Bob_Wallace

            “The prices offered by wind projects to utility purchasers averaged $40/MWh for projects negotiating contracts 2011 and 2012, spurring demand for wind energy.”
            http://newscenter.lbl.gov/news-releases/2013/08/06/new-study-finds-that-the-price-of-wind-energy-in-the-united-states-is-near-an-all-time-low/
            http://www1.eere.energy.gov/wind/pdfs/2012_wind_technologies_market_report.pdf

            Average. 4 cents per kWh.

            Average. Some places more. Some places less. Average.

          • John Storm

            Yet in most grids in the US wind displaces gas generation, not coal. Since gas emits no Hg or PM2.5 to speak of, wind should get no such environmental credit. And using your metric, gas and nuclear should also receive $34.00/MWh pretax PTC benefit, right? Do we or do we not wish to reward the technology with the lowest human health impact?

          • Bob_Wallace

            Wind, solar and natural gas combined are replacing coal.

            We are starting to see storage replace natural gas.

          • http://zacharyshahan.com/ Zachary Shahan

            externalities are subsidies. they are indirect subsidies from not pricing goods correctly.

          • John Storm

            Right-thus nuclear and CCGT are deserving of far more federal support since they are highly efficient and permanent means of reducing or totally eliminating coal’s externalities.

          • Bob_Wallace

            Sorry, but that simply is not true.

            Were we to convert our grid to nuclear our cost of electricity would triple and our economy would crash.

            Extensive use of CCGT would crash our climate. Plus there is nothing permanent about natural gas. Our supply is limited and prices will rise as we burn through the easier to obtain stuff.

          • John Storm

            Yet nuclear emits no CO2, SOx, NOx, PM 2.5 or Hg. And CCGT emits far less CO2 than coal and essentially no PM2.5 and no Hg. So you will struggle apply a 15 cent/kWh charge to their accounts.

          • Bob_Wallace

            The common false choice argument is once again thrown on the table.

            It’s not “Do we use nuclear or coal”.

            We use neither.

          • http://zacharyshahan.com/ Zachary Shahan

            do you feel comfortable ignoring historical subsidies: http://c1cleantechnicacom.wpengine.netdna-cdn.com/files/2011/09/historical-energy-subsidies-e1317160045713.png
            and the fact that fossil fuels and nuclear got a ridiculous amount more in subsidies (not including externalities) in their first 15 years than renewable: http://c1cleantechnicacom.wpengine.netdna-cdn.com/files/2011/09/subsidies-first-15-years-energy-e1317159794218.png

          • JayTee

            Yes Zach. Those are called sunk costs and can’t be changed now..

          • Bob_Wallace

            True. There’s no way to claw back that wasted money.

            Luckily the money we’re investing in clean energy is paying back enormous dividends.

          • JayTee

            Haven’t you read the two reports, both by public entities, that indicate renewables are more expensive than traditional means? One is written about on this website. Done by U. Of Delaware. Other by OECD.

            Perhaps some day renewables will be competitive. But that day is roughly 20 years in the future.

            The free market is a better way to get there than central planning. See Russia.

          • John Storm

            Unless you have a “way back machine” hidden in your closet, the answer is “yes”.

            And of course you must include the positive externalities of fossil fuels. Do you have a $/kWh in mind for the value of lifting the western world from a subsistence level existence?

          • Bob_Wallace

            How about we look at the real world?

            Wind is slipping under 4c/kWh. Solar is approaching 5c/kWh. Geothermal is under 10c/kWh. Storage is under 10c/kWh.

            That would mean a grid a bit more expensive than current wholesale prices which are low due to a lot of paid off capacity. Many of our existing plants are old and will need to be replaced over the coming years. Replacing a nuclear or coal plant that is now producing for 5c or less with new nuclear or coal plants producing for more than 15c would be a server shock to our economy.

            Most likely we’ll transition to renewables + storage with a small increase electricity price which will be offset by higher efficiency.

            Then were we to add in the external cost of fossil fuels and subsidies for nuclear we’ll realize an overall gain.

          • John Storm

            In 2010 renewables received more than 50% of all subsidies and supports: http://www.eia.gov/analysis/requests/subsidy/

          • Bob_Wallace

            You’re cherry picking. Nuclear and fossil fuels have received massively more subsidies over the years than have renewables.

            The only reason why renewables received in the year you picked out is simply that we are now installing wind and solar. When/if new nuclear comes on line it will get the same subsidy as wind and solar. In fact, nuclear will get far more.

        • John Storm

          Far more to the discussion than LCOE.

          Consider Paul Joskow, MIT economist:

          “In a nutshell, electricity that can be supplied by a
          wind generator at a levelized cost of 6¢/KWh is not “cheap” if the output is available primarily at night when the market value of electricity is only 2.5¢/KWh. Similarly, a combustion turbine with a low expected capacity factor and a levelized cost of
          25¢/KWh is not necessarily “expensive” if it can be
          called on reliably to supply electricity during all hours when the market price is greater than 25¢/KWh.”
          http://cadmus.eui.eu/bitstream/handle/1814/18239/RSCAS_2011_45.pdf?sequence=1

      • http://cleantechnica.com/ Zachary Shahan

        Actually, once everything is accounted for is exactly what LCOE is (except that it ignores externalities related to pollution, which would make wind the leader by even more).

        • John Storm

          EIA reports the LCOE of non-dispatchable sources separately from dispatchable generation because they have far different production profiles and are subject to the whim of weather rather than human command. They no longer list these sources in the same part of the chart for that reason.

          “The duty cycle for
          intermittent renewable resources, wind and solar, is not operator controlled, but dependent on
          the weather or solar cycle (that is, sunrise/sunset) and so will not necessarily correspond to
          operator dispatched duty cycles. As a result, their levelized costs are not directly comparable to
          those for other technologies (even where the average annual capacity factor may be similar)
          and therefore are shown in separate sections within each of the tables. ”

          http://www.eia.gov/forecasts/aeo/pdf/electricity_generation.pdf

          • Bob_Wallace

            You probably haven’t attended to how coal and nuclear plants fail from time to time.

            And you don’t seem to understand the ‘time of delivery’ issue. Nuclear suffers because it can’t be turned off and has to pump its output onto the grid when demand is low. Solar is more valuable because it delivers when demand is the highest.

      • Tomgraywind

        Longer blades, taller towers, and higher capacity factors has something to do with taking advantage of regions with slightly lower wind speeds, but better access to transmission (e.g., Ohio, Indiana, Illinois, etc.). So these technology developments are actually addressing the issues you raise. As others have noted, wind is getting very competitive, even with natural gas prices at historic (and likely temporary) lows. And that’s without taking environmental and health costs into account.

  • wattleberry

    Also,and this is becoming a more significant factor with the accelerating rate o  of progress with its consequent obsolescence, they are relatively easy to dispose of compared with, for instance, old power stations.

  • http://neilblanchard.blogspot.com/ Neil Blanchard

    I’ve been using a 40-45% Capacity Factor for wind for a couple of years now.

    Combine the Capacity Factor of wind to solar PV and/or tidal power and/or wave power  and/or biogas (which is from sewage / farm waste digesters)  and some grid storage — and you have a quite viable system.

    Neil

    • John Storm

      “I’ve been using a 40-45% Capacity Factor for wind for a couple of years now”

      Measured US fleetwide wind CF is just over 30% but in many parts of the US it is well below that. MI’s is only 25% despite having many “low wind” turbines in the fleet including the latest GE and Vestas stretch rotor models.

      • Bob_Wallace

        The median CF for us wind farms is 38%. Most people would say that is slightly less than 40%, not “just over 30%”

        Sure, in parts of the US CF is lower, but being the median we know that half the farms in the US have a higher CF. Some are now hitting 50%.

        http://en.openei.org/apps/TCDB/

        I suspect it you were to look closely you’d find that the lower CF numbers are coming mostly from older farms. As for your “25% despite” claim, the latest GE and Vestas turbines designed to lower speed wind areas have yet to be installed in any significant numbers.

      • Voodude

        If you’re not selling investments, who cares? One must “stretch the truth” to make a point, eh?

  • Ross

    I’ll try my hand at the exercise Zachary left for the reader. :-)
    One of the benefits of higher capacity factor is another thing that the wind haters like to go on about namely peaking capacity to smooth out the gaps when the wind isn’t blowing as hard. With higher capacity factors  less of it is needed. How much all that capacity is really needed is questionable due to other solutions like demand side management.

  • Captivation

    It looks like the techniques of climate denial and evolution denial are spreading into new domains.  The attacks on the EPA seem to hing on the notion that toxicity is healthy for the economy.  And now we have renewable energy denial.  In time, I believe that Darwin will clear up this whole problem by figuring out which side “fits” best within its ecological constraints.    

    • http://cleantechnica.com/ Zachary Shahan

      Definitely — pollution is a wonder drug now, good for everything… except global warming.

      Renewable energy is clearly the devil, and will strip us of our jobs, electricity (ironically), and America!

      • rkt9

        Yeah, and I like that I no longer have to add mercury to my occasional fish to spice up the flavor a bit, as it now comes pre-impregnated with it.  Thanks, coal industry! 

        • http://cleantechnica.com/ Zachary Shahan

          lol. that’s one we should really hammer home a little more.

    • Dot

      Not everything is clean with clean energy. Those wind turbines need rare earth elements, whose production in China is extremely dirty.

      With all the great numbers quoted, I would rather trust those provided by actual users, i.e. power companies operating those mills. At the end of the day, they are the only ones wo know how much does it cost to produce electricity by any gived turbine. Cant find those numbers, however.

      • Bob_Wallace

        China is cleaning up their rare earth mineral/element industry.  In fact, they hired an American corporation to help them out.

        Additionally, Japan just announced the discovery of a massive amount of rare earth element deposits just off their coast.  They will be in production in a few months.

        In case you missed my other reply – here’s the EIA numbers for the LCOE for all types of electricity production.    Your wish to locate numbers has been fulfilled.

        http://en.openei.org/apps/TCDB/ 

      • Captivation

        They’re only rare because the names are so bland.  In the old days  people would go prospecting for gold, silver, or diamonds.  Who wants to travel to Dawson City in search of Scandium, Yttrium, Lanthanum, Cerium, Praseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium?

        Either the names should be changed, or substitutes should be found.  I think it will be the later.

      • Bob_Wallace

        From Wiki –

        “As defined by IUPAC, rare earth elements (“REEs”) or rare earth metals are a set of seventeenchemical elements in the periodic table, specifically the fifteen lanthanides plus scandium and yttrium.[2]Scandium and yttrium are considered rare earth elements since they tend to occur in the same oredeposits as the lanthanides and exhibit similar chemical properties.
        Despite their name, rare earth elements (with the exception of the radioactive promethium) are relatively plentiful in the Earth’s crust, with cerium being the 25th most abundant element at 68 parts per million (similar to copper). However, because of their geochemical properties, rare earth elements are typically dispersed and not often found in concentrated and economically exploitable forms. The few economically exploitable deposits are known as rare earth minerals.[3] It was the very scarcity of these minerals (previously called “earths”) that led to the term “rare earth”.”

        You happen to notice that “not often found in concentrated and economically exploitable forms”?

        REEs/REMs are now more useful, which makes them more valuable, which in turn makes them more economically exploitable.

        That’s why were doing stuff like starting to process the waste water from geothermal plants at the Salton Sea to get lithium.  While not a REE, lithium now has higher demand so it makes sense to develop other sources than what we already were using.

      • http://cleantechnica.com/ Zachary Shahan

        nope, and we can’t walk around without killing insects. wind isn’t a holy technology, but it’s worlds better than its alternatives. so, we either go without electricity, or we use the cleanest option we have.

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