Economics, Energy and the Environment

Energy Fact of the Week: Why Wind Power Blows

Wind energy manufacturers and advocates must be enjoying the meltdown of solar power at the moment, as wind power has always been more competitive than solar with conventional fossil fuel electricity generation. Among other things, wind power doesn’t necessarily stop generating when the sun goes down.

However, the intermittency of wind power creates significant problems for grid operators that increase as the amount of installed wind power grows. The Department of Energy has noted this problem, writing last March on their website: “Often, wind generation does not coincide with the demand for electric power; wind resources are generally more prevalent overnight, when demand for electric power is at a minimum. In most areas, summer peak demand for electricity coincides with hot afternoons when consumers have turned up their air conditioners—but in many areas, such times are calm and wind resources may be quite low.”

The problem with any intermittent electricity source connected to the grid is that it requires a reliable backup source of power—usually natural gas these days—to ensure that the power reserves are adequate, especially for periods of peak demand such as summer heat waves, but also, as Texas found last winter, when unusually cold weather creates a spike in electricity demand. Last January, Texas experienced rolling blackouts because the grid was caught short. And wind production during that period was negligible.

The chart below from the Department of Energy, showing projections of the rated capacity of wind power by NERC (North American Electricity Reliability Corporation) region for the year 2019, cuts to the bottom line. While the installed capacity of wind power on paper—that is, assuming the wind is blowing at the right speed—looks impressive, in the real world grid operators can count on only about 8 to 13 percent of that capacity being available during peak times. (The table below shows the percentage of wind capacity available at peak times by NERC region). The Department of Energy’s headline for this release tells the story succinctly: “Electricity Resource Planners Credit Only a Fraction of Potential Wind Capacity.” This is one reason why the greenhouse gas emissions savings from wind power will diminish with the further spread of wind power.

Source: Energy Information Administration.

9 thoughts on “Energy Fact of the Week: Why Wind Power Blows

  1. Capacity factor for wind is more like 30%, these charts are misleading because they are capacity factor at peak demand. Obviously the wind generators will be producing during off-peak hours as well and the electricity will be consumed, particularly in a market with gas or hydro generation which is easily throttled according to wind output.

    Wind only “blows” when improperly implemented. Like everything in the world, energy sources all have positive and negative aspects, benefits and risks. Not to mention, there are few people (none I know of) who are proposing a 100% wind-powered grid. Someone who says we have “enough wind to power the entire nation” is using theory-over-reality hyperbole just as those who say “we have 250 years of coal” or “100 years of shale gas” or “nuclear fusion is infinite”.

    Wind is an intermittent force of nature with an unreliable output. Hydro blocks the natural flow of rivers. Nuclear produces waste that happens to emit ionizing radiation. Solar has a very high capital cost per continuous watt. Coal throws the Earth’s carbon cycle out of balance. And so on…

  2. It is unfortunate to see blatantly false claims being masqueraded as a “fact of the week” in Mr. Hayward’s post on the American Enterprise Institute’s blog. While I understand that an organization that receives a significant amount of funding from the fossil fuel industry would like to delay the transition to a clean energy economy, that is no excuse to degrade the quality of public discourse by making false statements. The most egregious false and misleading claims in Mr. Hayward’s post include:

    - “Last January, Texas experienced rolling blackouts because the grid was caught short. And wind production during that period was negligible.”

    First of all, the rolling blackouts occurred in February, not January. Second and more importantly, every grid reliability entity that has examined what happened in Texas has concluded that the blackout was caused by the unexpected failure of fossil fuel generators, and that wind generators’ very high output at the time actually played a major role in making the blackouts less severe than they would have been. In the authoritative report on the blackouts by FERC and NERC, the entities responsible for maintaining grid reliability, one learns that the blackout was actually caused by mechanical failures at over 100 fossil-fired power plants in Texas.

    Moreover, the Texas grid operator has repeatedly cited wind energy’s contribution in reducing the impact of the blackout, with their CEO noting at the time, “I would highlight that we put out a special word of thanks to the wind community because they did contribute significantly through this time frame. Wind was blowing, and we had over 3,500 megawatts of wind generation during that morning peak, which certainly helped us in this situation.”

    - “The problem with any intermittent electricity source connected to the grid is that it requires a reliable backup source of power…”

    As the Texas blackout and other similar events have shown, it would be far more appropriate to talk about the need to back up large fossil and nuclear power plants. They are the ones that experience large, immediate, and unexpected outages, requiring grid operators to keep 1,000-plus megawatts of fast acting, expensive and inefficient standby generation ready 24/7/365 in case one of those plants goes down. In contrast, changes in wind energy output occur slowly and are predictable, particularly when wind plants are spread over a large geographic area so their output becomes even smoother because weather changes at one location are canceled out by weather changes elsewhere. This allows grid operators to use slower-responding reserve generation that typically costs a few percent of what the fast-responding reserves that are needed for fossil and nuclear generation cost.

    Michael Goggin,
    American Wind Energy Association

  3. As I recall from reading the reports on the rolling blackouts in Texas last winter, wind’s contribution was insignificant. The wind was generally either absent, blowing too hard or the machines suffered from being “frozen”.

    Further, the events in Texas did not demonstrate that the thermal power plants need to be “backed-up”. Rather, the plants need to be designed for cold weather, as they are further north. That generally means heat tracing sensor lines, instrumentation and control valves and using more insulation on piping and valves.

    As a +40 year veteran of the power business, I see little need for “self-dispatching” power plants. Screws up the grid while making power more expensive for the consumer.

  4. PS While I am at it, wind was not much help during the recent Texas heat waves either. Peculiar thing about the summer and heat waves – the wind is generally not blowing.

  5. Wind studies for New England for 24% wind generation show:
    1) a cost of $63 billion or 24.5 cents per kWh for wind that will save burning 3 cents/kWh worth of natural gas. The report emphasizes that the gas plants must be kept to provide fast backup and that additional payments (not quantified) will be need to keep the gas plants online as they will lose revenue from the energy market.
    2) 4700 circuit miles of 500kV transmission must be added at a cost of $17B or 6.6 cents/kWh or twice the 3 cents/kWh of natural gas that will be saved with wind.
    3) Wind will cost $300-500 per ton of CO2 removed or about 10 times the expected CO2 market price..
    4) Retiring the >60 year old units and replacing with 4000MW of gas turbines will have exactly the came CO2 reduction as installing 12000MW of wind. The big difference is that the gas turbines and transmission would cost less than 1/10 as much ($5B versus $63B).

    The economics of wind are so poor that they should be considered a squandering of our capital resources. The 30% wind investment tax credit just adds more to the federal deficit.

  6. You must be very careful and not take any chances I know that sounds obvious but the fact is that it is bad errors and accidents that ultimately lead to regulations and sometimes an over-protective approach


  8. M. Goggin and the AWEA have no business critiquing S. Hayward. Their goal is to promote wind power and they are compensated financially. Americans have heard enough baloney starting with the Enron energy cartel, and people are rightfully skeptical of anything coming from the oil, wind, or coal industries. Perhaps Goggin could share his info on the carbon footprint of wind turbines which should be added up before any claims of C02 reduction are printed. How about it AWEA? The wind turbines are responsible for millions of tons of emissions before they ever start turning. Do they ever repay their own carbon debt? I bet you will not answer just like every pro wind politician or developer or wind company that has ignored my request. Stop the false claims.

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