1.3 Billion Wind Turbines Needed to Replace Coal

McFadden Ridge Wind Project

Tennessee wind turbines similar to McFadden Ridge
Tennessee wind turbines similar to McFadden Ridge

Construction of Rocky Mountain Power’s McFadden Ridge I wind project is underway in Albany County, Wyoming, near the towns of McFadden and Rock River. The project consists of 19 General Electric wind turbines, capable of generating a combined 28.5 megawatts of electricity.

See the Update section at the end of this post for a recalculation of the number of wind turbines needed to replace coal.

1.3 Billion Wind Turbines Needed

Now for a little back-of-the-envelope math. The McFadden Ridge project has 19 wind turbines producing 28.5 megawatts of electricity. Each wind generator therefore produces 1.5 megawatts. In the United States in 2007 coal was responsible for generating 2,016,456 gigawatts of power (see USA Electricity Generation 2007 Chart). As 1 gigawatt equals 1,000 megawatts you would need 1.3 billion (2,016,456,000 megawatts / 1.5) wind turbines to replace coal. And coal only accounts for 48% of electricity production.

651 Million More Wind Turbines

Petroleum liquids (49,505,000 megawatts), petroleum coke (16,234,000 megawatts), natural gas (896,590,000 megawatts), and other gases (13,453,000 megawatts) account for a total of 975,782,000 megawatts. To replace these sources of power you would need an additional 650,521,333 wind turbines. In these calculations we are not replacing the 21% of electricity generated from nuclear power. Even so, removing fossil fuels from the equation mandates the need for 2 billion wind turbines. And remember, wind power costs twice as much as electricity from coal.

Growing Electricity Needs

Rocky Mountain Power says:

To meet the growing electricity needs of its customers, Rocky Mountain Power is investing in new generation, transmission and distribution facilities in Wyoming and other states, as well as purchasing the output from wind projects owned by other entities.

These wind projects are to meet the growing electricity needs of its customers, not to replace coal generating plants. Construction of the McFadden Ridge I wind project is not even included in the 2 billion number cited. The wind turbines being constructed today are to meet growing demand, some of which will be met by even more expensive solar power. I would be very careful about trusting politicians that want to eliminate fossil fuels without giving an explanation of how we are going to replace them with the needed 2 billion wind turbines.

But whatever happens, please don’t put me in charge of turbine maintenance.


A co-worker, Josh, pointed out to me that my calculations were wrong. First the 1.5 megawatts output of the wind turbine needs to be multiplied by the number of hours in a year. Then the ratio of the maximum possible output to the typical output, called the capacity factor, needs to be calculated. For our purposes I will use a capacity factor of 30%. So now we arrive at the following:

1.5 megawatts x 24 hours x 365 days x 0.3 capacity factor = 3,942 megawatt hours.

Now with a more realistic divisor we arrive at the number of wind turbines needed to replace coal:

2,016,456,000 megawatt hours / 3,942 megawatt hours = 511,531 wind turbines.

I still don’t want to be in charge of turbine maintenance.

External Articles

This list is updated occasionally, with newer additions listed first.


  1. Silver Stop says

    I know that there’re 5 MW turbines now in production so the number would be about 400 mln. Still too many.
    There’s a plan to build about 200 sq kilometers solar panel power plant on Sahara – maybe it’s the solution ( it could be enough for half Europe I suppose)

    • The MW ratings for wind turbine generators are not true. On average they attain about one third there rated capacity. So a wind generator rated at 2.5 MW is only going to produce about .8 MW on average. When a coal fired power plant says it can produce 1200 MW it can and does produce 1200 MW. Wind generation “rated capacities” are false and blatant lies designed to hype the technology.

      • by my search: To replace coal….

        We need to build 194,900 wind turbines, each having 2 megawatts (MW) of power…this takes into account average production and its intermittent nature.

        A 2MW turbine costs $3.5 million dollars according to wind turbine sources,
        …(2 x 10>5) x (3.5x 10>6)

        == 7 x 10>11 == $700 billion

        This is about 1/3 of the money we will have spent due to the war in Iraq.

  2. I think even the wind power costs expensive that the coal, it at least the cleanest way of producing power which I think the most important factor why it should be preferred than other means that causes pollution.

  3. That sounds like a hell of a lot of wind turbines (doh!), but think realistically. The US is a huge place, and it would be easy to find space for them. The cost doesn’t need to influence power costs, it could be subsidised. At worst the US could raise capital from coal and oil export. The result of this? The US will then be the world leader in green energe, setting a precident for the rest of the planet. I think it would be worth it.

    • Anonymous says

      Yeah, let’s export our coal and oil and “subsidise” green. Yeah. Genius. The Subsidy Fairies can help!

      Where do you think all that steel comes from to make the wind turbines? Green aint clean. Usually just the opposite. The smallest Nuc reactor in the US makes as much electricity in 3 days as all the wind turbines in America do in a year.

  4. What about the pollution that is poisoning our Planet Rickety Ricky? There seems to be a convenient lack of the whole picture here… as usual. Oil is only going to be around for another 40 years max “per both sides of the political arena, coal, maybe 50 – 100 years. Fine for you old men but what about the next generations Rickety? What is your plan for them EXACTLY? Lay it all out for us

    • One thing about being old is that you’ve seen several end-of-the-world predictions fizzle out. For example, when I was growing up in England for sure we were all going to die from a nuclear war. Then we were going to starve to death by 1990. Then in the 70s we were all going to freeze in the next ice age. So one becomes skeptical of claims that the planet is going to burn up in the next half hour because of CO2 (plant food).

      The reason for this post was to point out that if you are going to rely on wind your numbers just don’t add up. Most things in life are a trade off. For a little pollution from coal plants one gets 2,016,456,000 megawatts of power a year for at least 240 years. The United States has over one quarter of all the recoverable coal in the world.

      As technology improves the pollution from coal reduces. We need coal to power the coming electric cars. If you want just wind and solar you are blowing in the wind at the moment.

      Here is my plan, as requested. Fire up as many coal plants as you can until nuclear plants can carry more of the load. Keep on coming with the electric-only cars. Use natural gas to heat more homes and run cars. I own a natural gas only car. Are you are still polluting the planet with your gasoline powered car? Reduce foreign oil consumption as much as possible this way and by encouraging tele-commuting.

      Speed up the adoption of solar panels on roof tops and look for new dams to be built. Be ready to use oil shale and off-shore drilling for our remaining oil needs. Remember, oil is used for many other things besides gasoline. And yes, wind turbines are fine too.

      But the most important thing to learn is that there is enough and to spare. The world was made for us to be wise stewards over it. And it is not wise to get all worked up over another end-of-the-world scare that ain’t gonna happen. Not for me, my children, or my grand children.

      Good comment, thanks for stopping by. Maybe you can share your plan for our energy future.

    • Weathervanes says

      We have to think in the long term. Of course fossil and nuclear are cheaper. What will be our energy source in 50-100 years if we are alive?

  5. Guess we’d better get started then, there is room out our way.

    Mind boggling stats though, thanks for the article.

  6. Using wind turbines to generate electricity really helps to minimize damage to ozone layer and climate change. But the noise pollution maybe irritating to the people near the place where wind turbines installed.

    • Do not forget, the aesthetic appeal as well, since they will need to completely dot the landscape. Access roads will need to be built to service the turbines and bird and bat populations will take a serious hit as well. I agree with Rickety we need to expand all source of energy production. Personally I’m not a big fan of wind power, it is inefficient and unreliable and has numerous negatives, which I feel out weighs the positives. I also view it as an antiquated source of power, which we use to utilize before even coal power, I see it as a step backwards not forwards.

  7. The other problem is that wind turbine don’t produce their rated output 24/7 the utilities are finding that on average they produce 20% given all the peaks and valleys of wind…

  8. Great article. I hope you dont mind if I link to this in a future post.

    • You are welcome to use it. Note that in the update the number of wind turbines needed was corrected to 511,531 — not 1.3 billion as stated in the title.

      • Thank you for the reminder. All I have to do now is research construction costs. (avg cost per plant already built, avg estimated output per plant already built, account for inflation, etc…)

  9. Ken Sparrow says

    If you are going to convert the 1.5MW wind turbine to MWH/year you have to convert the MW usage of the coal plants to MWU/year. Your figures only show coal as just MW not MWH. You have total coal generation at 2,016,456,000MW not MWH. Should this have been MWH?

    Lets look at the Comanche peak nuclear plant. It has two plants with a capacity of 2500MW. Divide 2500MW by 1.5MW amd you get 1667 wind turbines. to just to replace Comanche Peak. Using a capacity factor of 25% you have to multiply the 1667 by 4 which equals 6668 wind turbines and 146,696 acres of land.or 229.21 sq miles.See below.

    Now for the land needed. “The General Electric 1.5-MW wind turbine has a rotor diameter of 77 meters (262.6 feet).

    “To figure the spacing of the wind turbines, let us multiply the rotor diameter of 77 meters by 3, which gives us 231 meters as the spacing between the wind turbines. Now let’s figure the distance between the rows of wind turbines by multiplying the rotor diameter of 77 meters by 5, which gives us 385 meters between the rows.

    “If we multiply 231 by 385, it will give us the total area required to site one of our 1.5-MW wind turbines. This comes out to 88,935 square meters or 22 acres of land for one 1.5-MW wind turbine. If we now multiply the 22 acres by the 6,668 wind turbines, we get 146,696 acres, which is 229.21 square miles. So it appears that it will take 146,696 acres of land covered with wind turbines, to have a part-time generating capability equivalent to that achieved on 4,000 acres of land for the nuclear power plant (which includes a lake used to provide water to the cooling towers).”

    • You have total coal generation at 2,016,456,000MW not MWH. Should this have been MWH?

      Correct. In the update at the end of the article I used MWH: 2,016,456,000 megawatt hours / 3,942 megawatt hours = 511,531 wind turbines.

  10. Your math is wrong because the source you used had a typo. 2,016,456 gigawatts should instead be 2,016,456 GIGAWATT HOURS if you look at the chart right below in the link. You also assume that turbines will stay at 1.5 megawatt capacity but they are working on 10 megawatt turbines as we speak. When all is said and done we may only need about 100 thousand turbines to completely replace coal, a far cry from the 1.3 billion you listed.

    • You didn’t see the update I posted over a year ago? I adjusted the numbers to 511,531. The 1.5 megawatt capacity turbines were the type generally in service in 2009 when I wrote the article.

      Agreed, the higher capacity turbines will reduce the numbers needed. However, read Ken Sparrow’s comment above.

  11. Again, there is the important need to think about the big and long range picture. We want, not need, a lot of electricity. The issue needs to be addressed from a lot of angles. We might not replace coal and probably won’t until it is gone along with clean air, the mountains and cherished places under which the coal lies. So, we still need to be not just thinking about, but developing alternatives that aren’t going to poison ourselves. Wind is one of them. Why not? Solar is one of them. Why not? The more they are worked on the more efficient with more output they have become capable of. We are developing more efficient appliances but we want more and more appliances. We all want electric towel warmers, toothbrushes, massage chairs, lawn mowers, home movie theaters. We could at least orient homes efficiently to the free sun simply for passive solar gain heat to add to whatever heat sources we use. Around here bigger and bigger homes for two people are being built faster than you can look, oriented to the windy north, or anywhere BUT where they can take advantage of free energy. No wonder our electricity demands are increasing. More and more there is a chip on the shoulder expression that part of American freedom includes the right to use just as much energy as we possibly can regardless of what it is doing to us and where we live. The mantra, “Think of the children and grandchildren.” is gone. We also don’t think about the incredibly increasing number of people that we think we need just to sustain our idea of economy which is based on an ever growing number of consumers. Even coal can’t keep up with that idea. So this discussion about wind replacing coal I find mis guided. I’d like to read it take a turn to a more realistic inclusion of what people foresee for the future 50 to 100 years from now.

    • The most compelling reason to use coal is that it is cheaper – much cheaper than solar or wind power. The US has the most coal reserves of any nation, 237,295,000,000 tons of proved recoverable, which is 22.6% of the world’s total.

      If someone wants to install solar panels on their roof then they can go ahead, the government will help pay for it. Last year I installed insulation in my attic after crunching the numbers, with the help of a 50% rebate. But even with tax credits it would take at least 20 years for solar panels to pay for themselves on my roof. I pay 9 cents a Kwh currently for power but even at that price I do not use more than I need.

      The argument for solar and wind power needs to be made from an economic standpoint, otherwise it will not gain much traction, especially when goverment subsidies and tax credits end (think austerity). However, I support efforts to reduce imported oil, and wind and solar play a part there. I do not support forcing people to unnecessarily pay three to five times more for electricity just because of theories about anthropomorphic climate change.

      The U.S. is in a virtual tie with Russia as the world’s largest natural gas producer. I am a great fan of natural gas vehicles, see http://www.rickety.us/2009/11/driving-on-the-cheap/

      If a similar amount of energy and resources that is being thrown at “free energy” was devoted to running our vehicles on natural gas, the environment and balance of payments would greatly benefit. And the economics would actually make sense.

      Thank you for your well written comment, I enjoyed reading it.

  12. wayne larson says

    um i can see about 50 turbines from my home, they are 15 miles away. i have loged on average in a month 15 days with no wind no power? and when they shoot power to them from conventional power plants hoping they will at least turn enough to collect the subsidy who pays for that? so yes when they state the installed energy numbers it’s a joke. for full out put the wind must blow 35 to 45 miles an hour 24 hours a day and 365 days a year. this is nothing but fraud in numbers to the public tax payer. we have homes here in that area that folks have been trying to sell for 2 years now, they cant afford to move and no one will buy their homes? researchers also have found that after one year turbines loose 20% of production from wear and tear but average only 30% production when new. so if most of these turbines contain between 300 to 400 gallons of oil to operate what fossil fuel are we saving again? positive note all the blinking lights always work though. now i have been to friends homes to witness the sound and pressure myself and when they do run it’s amazing to hear and feel but scary to think if you live as close as these are to many homes it is appauling when i hear wind mine people say they are crazy. no they are not, honestly my hearing is not as good as it use to be but my grandson being 9 years old started holding his ears and pleaded for us to leave. i feel so sorry for these people and their children they are trapped in their homes and don’t go outside when they do spin, thankfully for them it’s very seldom. Co2 reduction cracks me up, if one would think about what china’s emitting into the air and water just to create the magnets they would be in awe, not to mention steel and concrete production are the 2 biggest contributers to Co2. and the constant ramping of area power plants from turbines is astounding. these turbines did’nt work in the 18th century and all they have done is make the taller and taller with the same outcome, can’t wait till they start burying tons and tons of the batteries in the ground next, they alreay had a few of these battery stations catch on fire which are now considered toxic sites. i want my tax money back wat are we up to now 250 billion in paid subsidies for blasting mountains and clearing forrests ,next they will say all the homes are in the way of the wind and we must live in the ground so we don’t disrupt the wind when it blows. just crazy.

  13. The actual capacity factor of a wind turbine is between 7 and 8 percent not 30 percent as you state. So instead of 500,000 turbines required the actual need would be 2 billion turbines or so.

  14. Fred Mullins says

    I haven’t heard a word as to who is willing to allow wind turbines in areas where wind blows consistantly. Just any available spot won’t do. Unfortunately, that’s along mountain tops, ridge lines or along the coast – places where people don’t want the natural beauty of the landscape altered by these massive machines. Perhaps better use of electricity (better insulated homes/businesses, passive solar, etc.) could assist in lowering costs and the need for even more turbines. Electric cars, if used on a national scale, will undoubtedly raise demand even farther.

  15. Given the corrected numbers consider that the continental US is roughly 3 million square miles so there would need to be 1 wind turbine on average every 6 square miles (6 square mi. Is a 2.45 x 2.45 mi. square). That would be a turbine every 2 and a half miles. Yikes.


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