Wind turbines hit limits to growth before 50% wind power penetration

Material requirements of 50% wind power in the USA hit limits to growth

Also see:

Davidsson, S., et al. 2014. Growth curves and sustained commissioning modelling of renewable energy Investigating resource constraints for wind energy. Energy Policy.

Fizaine, F., et al. July 2014. Energy transition toward renewables and metal depletion: an approach through the EROI concept. Les Cahiers de la Chaire Economie du Climat.

Wind turbines can’t be made forever because lower grade ores require more and more energy at a time when energy resources are declining.  The natural gas, coal, oil, uranium (thorium), neodymium, and other energy resources and minerals needed for wind turbines are finite.  It takes energy to recycle, and few metals are cycled as much as they ought to be, and some can’t be recycled.

Since wind and solar need to provide the lion’s share of renewable energy in the future, but wind only blows 32 percent of the time nationally, you’d want to build at least three times as many wind turbines to store energy while the wind is blowing for calmer times. Or perhaps even five times overcapacity to cope with the seasonal nature of wind, which is only at 21 percent capacity in August. Plus you’ll need to generate more electricity than in 2014 for the billion people expected by the end of the century, so perhaps six times more.  Or let’s go for seven times more, since endless growth is the solution offered by both political parties as the way out of our economic doldrums, especially “green” growth.

Tripling the number of wind turbines to compensate for the 32% capacity gets you:

5,606 MWh power/year per turbine = 2 MW * .32 capacity * 24 hrs * 365 days

730,099 windmills = 4,092,935,000 MWh /5606 MWh (EIA 2015 1.1) = needed.  Cross-check: NREL estimates that 893,698 1.5 MW turbines are needed for 80% wind penetration by 2020 in class 4 wind, 2 x 40% case = 3914 TWh (NREL 2006)

$2.2 to $2.9 trillion dollars (@ $3 to $4 million per windmill)

This won’t provide 100% of America’s energy because the round-trip efficiency of most energy storage is 80%, wind capacity is 25 percent in summer, wind turbine performance declines over time, non-prime locations will lower the average wind capacity, two to nine percent of electricity is lost over transmission lines, and their lifespan is 20 years, so increasing numbers will need to be replaced or out of commission from repairs.

Area required is 193,933 square miles = (85 acres/MW (NREL 2009) * 2 MW turbines * 730,099). That’s about 72 percent of Texas, or California plus South Carolina, or .66% of the total lower 48 states, but doesn’t include the roads, transmission line and tower corridors, and other equipment.

Material Short Tons Tons for 730,099 2 MW turbines Production in short tons per year
Concrete 1302.35 950,844,433      142,464,000 United States (USGS)
Steel 292.75 213,736,482    1,800,064,000 world-wide (worldsteel)
Iron 48.35 35,300,287
Fiberglass 24.4 17,814,416 1,523,200 (USA 2005 production)
Copper 4.1 2,993,406 20,048,000
Neodymium 0.4 292,400          7,840 world-wide (ED)
Dysprosium 0.065 44,456              112 world-wide (ED)


Materials per 2 MW turbine (average of Guezuraga, USGS). Fiberglass annual production (NREL 2006).

Clearly materials can be imported, more manufacturing built up – but as energy declines and the financial system copes with shrinkage, the opposite of the current borrowing and paying back the money from growth, it’s not clear that ramping up is likely — quite the opposite is possible, with many businesses going bankrupt.

Fiberglass would require 100% of production for 11.7 years.

Materials not included: vehicles, cranes to hoist blades and tower, thousands of miles of transmission lines & towers, substations, utility-scale energy storage, etc.

ED. 2015. Neodymium. Dysprosium.

EIA. 2015. Table 1.1. Net Generation by Energy Source: Total All Sectors, 2004-December 2014. Energy Information Administration.

EIA. 2015. Table 6.7.B. Capacity Factors for Utility Scale Generators Not Primarily Using Fossil Fuels, January 2008-November 2014. U.S. Energy Information Administration.

Guezuraga, B. 2012. Life cycle assessment of two different 2 MW class wind turbines. Renewable Energy 37:37-44.

NREL. 2006. High Wind Penetration Impact on U.S. Wind Manufacturing Capacity and Critical Resources. National Renewable Energy Laboratory.

Prieto, P. A.  21 Oct 2008. Solar + Wind in Spain/ World. Closing the growing gap? ASPO International conference.

USGS. 2011. Cement production. United States Geological Society. 127,200,000 long tons converted to 142,464,000 short tons (2,000 lbs)

USGS. 2011. Wind Energy in the United States and Materials Required for the Land-Based Wind Turbine Industry From 2010 Through 2030. U.S. Geological Survey.

Worldsteel. 2014. Monthly Crude Steel Production 2014Pig iron 2013 + DR 2013. (converted from long to short tons).

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2 Responses to Wind turbines hit limits to growth before 50% wind power penetration

  1. Patrick Walden says:

    You have reported that the world steel production in 2014 was 1,833,395 short tons. I believe you read your reference incorrectly. If you look at the top of the table it says the figures in the tables are in units of thousands of tonnes (long tons). Hence for 2014 the world output was
    1,636,960,000 tonnes or 1,804,440,995 short tons. There is a little note at the bottom of the table that says these 65 countries were responsible for 98% of the world’s steel production in 2013. Putting in this correction gives 1,841,266,322 short tons. Thus your number is a factor of 1000 off. The amount of steel required to build 361,926 turbines amounts to be 96,091,353/1,841,266,322 = 5.22% of global yearly output. The thesis on which this excerpt is based is thus null and void. I was about to release a statement based on this information. I am glad I checked it out and saved myself some embarrassment. The number one rule in writing material like this is to make sure it is absolutely correct before releasing it.

    • energyskeptic says:

      I agree with you and caught it myself yesterday and I’ve updated the post, because I changed several other calculations. I do so appreciate your finding my mistakes! Newspapers have the luxury of fact checkers, this is one of the sad aspects of bloggers like myself, I often don’t catch my errors until the 2nd or 3rd draft, or never if I move on to something else. On the other hand, newspapers have let us down, they ought to cover energy, ecology, infrastructure, metal recycling, biodiversity, ocean acidification and the real issues facing us today.