How big are America’s wind turbines?

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The question for this blog post is a rather simple minded one. But sometimes simple questions are worth asking. So, let’s answer a couple.

How big is the average wind turbine in America?

Oddly, Google does not throw up an answer to this question. So, I will have to estimate this here.

We can do it using data from the United States Geological Survey, which I discussed last week. They publish a data set covering most of the wind turbines in existence in America in July 2013. This provides geographical co-ordinates, turbine height and capacity of each turbine, more than enough to provide an answer to the question above.

The data set covers turbines of a total capacity of 60.7 GW. According to BP, the total capacity of America’s wind farm fleet was 61.3 GW at the start of 2013. So, we can be reasonably confident that this data can be used to get a reasonable estimate of the average size of America’s turbines.

In total, there are 41,058 turbines. This means that the average capacity of America’s wind turbines is approximately 1.5 MW. Similary, the average height is 113 metres.

Has the average size of American wind turbines increased over time?

USGS also tells us when a wind turbine came online. As a result, we can estimate the average size of wind turbines that came on each year for the last 20 years.

Here is a time series of the evolution of the size of American wind turbines.


Average turbine capacity doubled between 2000 and 2010. However, the average capacity of new turbines appears to have reduced slightly in recent years.

Turbine height did not double, but rose by just under 50%. Keep in mind that the kinetic energy that flows through a wind turbine is proportional to the swept area of the turbine blade.

In the long run there is no technical reason the average turbine height will not keep rising. 10 MW wind turbines are now planned for offshore locations. However, it is likely that there will be a cap on the maximum size because of NIMBY opposition to turbines – no one likes to live near a 200 metre tall wind turbine. So another doubling in average turbine capacity may be off the cards.


2 thoughts on “How big are America’s wind turbines?

    Keith Brown said:
    May 20, 2015 at 5:53 pm

    The phenomenon of taller wind turbines without increasing capacity per turbine is suspicious of the fraud going on here in the UK. The subsidy levels have breaks in them at 50kW, 500kW and 1500kW. At 50kW they get more than four times the wholesale price of electricity in FITs and a bit more from RECs, plus the wholesale price of electricity as well. A 50kW rated device would generate about 15kW on average. So, what they do is re-badge a more powerful machine with a false 50kW nameplate capacity, maybe with a sacrificial governor at the rarely achieved top output level to “justify” the trick, so as to arrive at a contrived load factor more like 50% compared to the usual 25-30% range. Bingo! suck on max subsidy with a falsely rated higher output machine. I think the Endurance 3150 falls into this category (Google it for yourself and look at the spec). Got some round here, well over 100 foot tall, right on the border of an AONB, producing just about enough electricity to keep maybe 10 kettles boiling, even allowing for the higher load factor. On average of course. The owner has informed us he is saving the planet. He will collect about £1.5m over its lifetime, of which 80% is pure subsidy. To produce all of our energy needs (i.e. not just the 20% or so which is electricity) would require about 10 million of these (on average). There are 90,000 square miles in Great Britain. Go figure. as they say.


      Robert Wilson said:
      May 20, 2015 at 6:09 pm

      Thank you for your rant. Always helpful


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