Tag Archives: US Energy Information Administration

Building a Modern Wind Turbine Generator

MidAmerican Energy Company, Iowa’s largest energy company, began installing wind turbines in 2004. In May 2013, MidAmerican Energy announced their latest plan to invest up to $1.9 billion to expand its wind generation fleet and add up to 1,050 MWe of wind generation in Iowa by year-end 2015. Once this expansion is complete, approximately 3,335 MWe, or approximately 39%, of MidAmerican Energy’s total owned generation capacity will come from wind-powered generation from 1,715 wind turbines.

MidAmerica Energy wind turbines Source: MidAmerica Energy

You can visit the wind energy page on the MidAmerica Energy website at the following link:


Fact sheets on this site provide details on the two types of wind turbines currently being installed:

  • 1.5 MWe General Electric wind turbine (most common in the MidAmerica fleet)
  • 2.3 MWe Siemens wind turbine (largest in the MidAmerica fleet)

The impressive dimensions of the larger Siemens machine are shown in the following diagram:

MidAmerica Energy 2.3 MWe wind turbine Source: MidAmerica Energy

MidAmerican Energy Company has posted a 5+ minute time-lapse video on YouTube showing their three-week construction process for the Siemens wind turbine. This is worth watching to get a better understanding of the modest site preparation work required, the very large scale of the pedestal and rotor components, and the short time frame required to complete a wind turbine generator and have it ready to be put into revenue-generating service.  You can view the video at the following link:


Now complete this process several hundred times and you have a respectable sized wind farm.

The U.S. Energy Information Administration (EIA) defines “capacity factor” as follows:

“Capacity factors describe how intensively a fleet of generators is run. A capacity factor near 100% means a fleet is operating nearly all of the time. It is the ratio of a fleet’s actual generation to its maximum potential generation”.

EIA reports average monthly and annual capacity factors for utility generators. For utility generators not primarily using fossil fuels, the results are at the following link:


Here are average capacity factors reported by EIA:

EIA capacity factors 1

As a renewable power source, wind has a significantly higher capacity factor than solar. However, over the long term, a wind farm delivers only about one-third of it’s “nameplate rating.” This statistic, of course, does not capture the real-time variability in electrical output as wind conditions constantly change.

As a point of comparison, you can find the EIA capacity factor results for utility generators primarily using fossil fuels at the following link:


Here are average capacity factors reported by EIA for selected fossil generators (I only included those that are likely to be base loaded):

EIA capacity factors 2

EPA Clean Power Plan Proposed Rule Does Not Adequately Recognize the Role of Nuclear Power in Greenhouse Gas Reduction

On June 2, 2014, the U.S. Environmental Protection Agency (EPA) proposed what they called, “a common sense plan to cut carbon pollution from power plants.”  You can access the Clean Power Plan Proposed Rule and many related documents at the following EPA link:


This Plan proposes to limit carbon emissions from existing fossil fuel fired electric generating units, including steam generating, integrated gasification combined cycle, or stationary combustion turbines (in either simple-cycle or combined-cycle configuration) operating or under construction by January 8, 2014. Main points of the Clean Power Plan include:

  • Wind and solar power are the preferred EPA options.
  • Natural gas is an interim solution.
  • New nuclear capacity is not a compliance option.
  • The EPA allows compliance credit for:
    • New nuclear plants currently under construction, and
    • Preservation of existing nuclear plants that might otherwise be retired

I’ve already formed my opinion on the Clean Power Plan. To help you form your opinion, I recommend that you refer to the following recent analyses by four respected government and industry organizations that have reviewed the Clean Power Plan.

Institute for Energy Research (IER)

On 15 June 2015, the IER issued the results of their analysis entitled, EPA’s Clean Power Plan Ignores New Nuclear as a Compliance Option. IER concluded that the compliance formulae in the Clean Power Plan are biased toward new wind and solar power development. Deployment of these technologies, which currently are not capable of delivering reliable capacity, will decrease the reliability of the electric grid. IER also concluded that the Clean Power Plan will result in much higher electricity prices for all American consumers, while having only a marginal impact on global temperature based on EPA’s computer models.

You can read the IER analysis at the following link:


National Association of Clean Air Agencies (NACAA)

On 21 May 2015, the NACAA issued a report entitled, Implementing EPA’s Clean Power Plan: A Menu of Options, containing 25 chapters, each of which explores a particular approach to greenhouse gas (GHG) reduction in the electric power sector.  NACAA is a nonpartisan, nonprofit association of air pollution control agencies in 41 states, the District of Columbia, four territories and 116 metropolitan areas.  Each chapter of their Menu of Options includes a brief descriptions of: (1) the option and it’s pros and cons; (2) the regulatory backdrop, policy underpinnings, implementation experience, and GHG reduction potential associated with the option; and (3) benefits of the option to society and the utility system, including costs and cost-effectiveness. In the last chapter, a variety of emerging technologies and other policy options for reducing GHG emissions are addressed.

An interesting table and two figures included in Chapter 6 of the Menu of Options are reproduced below.

NACAA Table 6-1 Source: NACAA

In 2012, electric power generation technologies with zero or low GHG emissions accounted for 31.4% of the USA’s total generating capacity. The data in Table 6-1 shows that 82.2% of the zero or low GHG emission generating capacity came from nuclear and hydroelectric power plants. The remaining low-emission generation capacity came from biomass, wind, geothermal, and solar power plants.

NACAA Figure 6-3Source: NACAA

In Figure 6-3, “life cycle GHG emissions” include those associated with operation as well as construction, fabrication, and fuel processing.  While nuclear power is not included among the “technologies powered by renewable resources”, it’s clear in Figure 6-3 that nuclear power meets the GHG reduction performance of the other technologies using renewable resources.

NACAA Figure 6-7  Source: NACAA

In Figure 6-7, note the relative cost-of-energy differential between nuclear power and fossil power. This difference makes it difficult for nuclear power plants to compete head-to-head with coal and natural gas merchant power plants and encourages the early retirement of some nuclear power plants on economic grounds.  While most renewable power sources have even higher costs-of-energy, various financial schemes subsidize their power generation.

You can download individual chapters or the entire NACAA Menu of Options at the following link:


U.S. Energy Information Administration (EIA)

On 22 May 2015, the EIA released their analysis of the Clean Power Plan. The EIA analysis supports the IER finding that the Clean Power Plan will result in much higher electricity prices for all American consumers, even in a scenario that allows GHG reduction credit for new nuclear generation.

You can read the EIA press release at the following link:


You also can download a PDFs copy of the May 2015 EIA report, Analysis of the Impacts of the Clean Power Plan, at the following link:


Nuclear Energy Institute’s (NEI)

To address the “clean power” attributes of nuclear power, I refer you to an NEI Knowledge Center webpage: Environment: Emissions Prevented, which you will find at the following link:


Here you’ll find a link to data on the amount of sulfur dioxide, nitrogen oxides, and carbon dioxide emissions avoided in the U.S. during the years 1995 to 2014 by virtue of having about 20% of U.S. electric power generated by nuclear power plants instead of fossil power plants. NEI reports the total avoided emissions for this period as follows:

  • Sulfur dioxide: 57.75 million short tons (52.4 million metric tons)
  • Nitrogen oxides: 22.92 million short tons (20.8 million metric tons)
  • Carbon dioxide: 13,063.6 million short tons (11,851 million metric tons)

On this website, NEI states:

“Nuclear energy facilities avoided 595 million metric tons of carbon dioxide in 2014 across the U.S. This is nearly as much carbon dioxide as is released from nearly 135 million cars, which is more than all U.S. passenger cars. The U.S. produces more than five billion metric tons of carbon dioxide each year.

Without the emission avoidances from nuclear generation, required reductions in the U.S. would increase by more than 50 percent to achieve targets under the Kyoto Protocol.”

2013 paper, “Prevented Mortality and Greenhouse Gas Emissions from Historical and Projected Nuclear Power”.

Supporting the above NEI position on the GHG reduction merits of nuclear power, there is a related 2013 article by NASA scientists from Goddard Institute for Space Studies and Columbia University entitled, “Prevented Mortality and Greenhouse Gas Emissions from Historical and Projected Nuclear Power”.  You can read a short article on this paper on the Scientific American website at the following link:


You also can read the complete paper at the following link:


In their study, authors Pushker A. Kharecha and James E. Hansen used historical production data from 1971 to 2009 and calculated that global nuclear power has prevented an average of 1.84 million air pollution-related deaths and 64 gigatonnes of CO2-equivalent (GtCO2-eq) greenhouse gas (GHG) emissions that would have resulted from fossil fuel burning. From their analysis, the authors drew the following conclusion:

“In conclusion, it is clear that nuclear power has provided a large contribution to the reduction of global mortality and GHG emissions due to fossil fuel use. If the role of nuclear power significantly declines in the next few decades, the International Energy Agency asserts that achieving a target atmospheric GHG level of 450 ppm CO2-eq would require “heroic achievements in the deployment of emerging low- carbon technologies, which have yet to be proven. Countries that rely heavily on nuclear power would find it particularly challenging and significantly more costly to meet their targeted levels of emissions.”

So, what do you think about the EPA’s proposed Clean Power Plan? Is this the “common sense plan to cut carbon pollution from power plants” promised by EPA; a politically motivated piece of crap designed to kill the nuclear and coal power industries; or something in between?