Power Hungry (16 page)

But those numbers must be adjusted to account for wind's capacity factor—the percentage of time the generator is running at 100 percent of its designed capacity. Given that wind generally has a capacity factor of 33 percent or less, the deployment of 1 megawatt of reliable electric-generation capacity at Milford actually required about 956 cubic meters of concrete. The concrete numbers on the Milford project are similar to those described in a report delivered by Per Peterson to the President's Council of Advisors on Science and Technology in September 2008. Peterson, a professor in the nuclear engineering department at the University of California at Berkeley, reported that when accounting for capacity factor, each megawatt of wind power capacity requires about 870 cubic meters of concrete and 460 tons of steel.

For comparison, each megawatt of power capacity in a combined-cycle gas turbine power plant (the most efficient type of gas-fired electricity production) requires about 27 cubic meters of concrete and 3.3 tons of steel. In other words, a typical megawatt of reliable wind power capacity requires about 32 times as much concrete and 139 times as much steel as a typical natural gas-fired power plant.

To be fair, the concrete and steel requirements of a gas-fired power plant are only part of the electricity equation. The miles of steel pipelines required to move gas from the wellhead to the turbines, and the steel and concrete used to line each gas well, must also be included in any
rigorous materials-intensity analysis of the life cycle of natural gas as it relates to electricity production. That said, the resource intensity of wind is also far higher than that of our other favorite fuel: nuclear.

FIGURE 12
Resource Intensity of Electric Power Generation Capacity: Comparing Wind with Natural Gas, Nuclear, and Coal

Source
: Per F. Peterson, “Issues for Nuclear Power Construction Costs and Waste Management,” September 16, 2008,
http://www.ostp.gov/galleries/PCAST/PCAST%20Sep.%202008%20Peterson%20slides.pdf
, 4.

Peterson's report shows that the concrete and steel requirements for wind are 9.6 times greater and 11.5 times greater, respectively, than those needed for a nuclear power plant. Each megawatt of power capacity in a nuclear power plant requires about 90 cubic meters of concrete and 40 tons of steel.
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Even though wind power has low power density and a huge appetite for steel and concrete, it appears that it will continue to be pursued in the years ahead, with wind turbines being located across the country. The entire wind industry will nevertheless be dogged by the fundamental problem of power density, because the math makes it unavoidable. And the power-density challenge is fundamentally about ethics and aesthetics.

Energy sources with high power densities have the least deleterious effect on open space. They allow us to enjoy mountains, plains, and deserts without having our views obstructed or disturbed by spinning wind turbines, sprawling solar arrays, towering transmission lines, or miles of monocultured crops. As the architect Witold Rybczynski wrote in
Atlantic Monthly
in an essay expounding the environmental benefits of cities, “density is green.”
²⁷

Rybczynski's endorsement of cities echoes that of Stewart Brand, who, in his latest book, the
Whole Earth Discipline
, argues that cities, and even densely populated slums, provide a path out of poverty for millions of people. Brand says that “cities are probably the greenest things that humans do.”
²⁸

Embracing the density of cities make sense. And to properly fuel them, we need energy sources with the highest possible densities. Energy projects with small footprints are not only green, they reduce the potential for NIMBY objections. And that not-in-my-backyard attitude is particularly virulent among people like Phil and Wendy Gramm, who can afford to fight power lines and other infrastructure projects. In fact, NIMBYism even occurs among the most ardent supporters of wind power. T. Boone Pickens wants to carpet the Great Plains with thousands upon thousands of wind turbines and endless rivers of transmission lines. But the Dallas-based billionaire wants those turbines and transmission lines on other people's land, not his. In May 2008, Pickens declared that his 68,000-acre ranch, located in the Texas Panhandle, one of America's windiest regions, will not sport a single turbine.

“I'm not going to have the windmills on my ranch,” quoth he. “They're ugly.”
²⁹

Ugly or not, wind power has become the most-hyped segment of the “green” energy alternatives. And few aspects of the wind-power hype have gotten more attention than the claim that adding wind turbines will mean big reductions in carbon dioxide emissions. There's only one problem with that claim: It's not true.

Wind Power Reduces CO
₂
Emissions

G
IVEN THE HYPE about wind power, it would be logical to assume that wind-power advocates have multiple studies on their shelves to prove that wind power cuts carbon dioxide emissions. The problem: They don't have a single study to support that claim. Yes, they have reports based on models that look at various scenarios of wind-power use, and those models provide projections about what the carbon dioxide reductions might be.

But the wind-power boosters do not have a single study—based on actual data collected from the world's existing fleet of wind turbines and conventional electricity-generation plants—showing that wind power actually reduces carbon dioxide emissions. That's remarkable, given that the Global Wind Energy Council has declared that “a reduction in the levels of carbon dioxide being emitted into the global atmosphere is the most important environmental benefit from wind power generation.”
¹

In 2009, when I asked the American Wind Energy Association for studies proving that wind power reduced carbon emissions, association officials pointed to two reports relying on models that assume certain levels of future reductions.
²
The Global Wind Energy Council could only provide its annual report, “Global Wind Energy Outlook 2008,” which, like the reports that used models, claimed that wind would, sometime in the future, decrease the use of hydrocarbons for electricity production.
³

But that claim ignores the fact that all wind-power installations must be backed up with large amounts of dispatchable electric generation capacity. In Denmark's case, that has meant having large quantities of available hydropower resources in Norway and Sweden that can be called upon when needed. But even with a perfect zero-carbon backup system, the Danes haven't seen a reduction in carbon dioxide emissions. (Denmark's wind sector is discussed at length in the next chapter.) And that bodes ill for countries that don't have the access to hydropower that Denmark has. Nearly every country that installs wind power must back up its wind turbines with gas-fired generators.

This reality was explained in a 2008 report by Cambridge Energy Research Associates (CERA). In the 23-page report, the firm concluded that wind power “is more expensive than conventional power generation, in part because wind's intermittent production patterns need to be augmented with dispatchable generators to match power demand.”
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The CERA report goes on to explain that wind turbines may be good for producing electricity during fall and spring, but wind power “has limited capability as a capacity resource as its production patterns generally do not correlate well with peak summer demand. Consequently, the capacity provided by wind projects is typically valued at 10% to 20% of their maximum rated capacity.”
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In the electric power business, generating plants are rated by their “capacity factor,” which is based on the amount of time they will produce power at 100 percent of their maximum output. As the CERA report makes clear, many wind projects have a capacity factor of 10, 20, or 30 percent. But some grid operators are using capacity factors that are far lower than the estimates from CERA. For proof of that, look no further than the Lone Star State.

Texas has repeatedly been lauded as a leader in wind power development. In 2008, the state installed nearly 2,700 megawatts of new wind capacity, and by early 2009, if Texas were an independent country, it would have ranked sixth in the world in terms of total wind-power production capacity.
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Republican governor Rick Perry, among the state's most ardent supporters of wind power, declared a few years ago that “no state is more committed to developing renewable sources of energy.” He went on to say that by “harnessing the energy potential of wind, we can
provide Texans a form of energy that is green, clean and easily renewable.”
⁷
The Lone Star Chapter of the Sierra Club has also repeatedly trumpeted wind-power development, saying that it “means more jobs for Texas, less global warming from coal plants and less radioactivity from nuclear plants.” The group says that wind power in the state “has exceeded all expectations,” bringing in “an estimated $6 billion in investments and 15,000 new jobs” for the state.
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In June 2009, shortly before the U.S. House of Representatives was to vote on a major cap and trade bill aimed at increasing use of renewable energy, President Obama reminded reporters that Texas had one of the “strongest renewable energy standards in the country.... And its wind energy has just taken off and been a huge economic boon to the state.”
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Alas, the hype doesn't match the reality. The Electric Reliability Council of Texas (ERCOT), which manages 85 percent of the state's electric load, pegs wind's capacity factor at less than 9 percent.
¹⁰
In a 2007 report, the grid operator determined that just “8.7% of the installed wind capability can be counted on as dependable capacity during the peak demand period for the next year.” It added that “conventional generation must be available to provide the remaining capacity needed to meet forecast load and reserve requirements.”
¹¹
In 2009, the grid operator reaffirmed its decision to use the 8.7 percent capacity factor.
¹²

By mid-2009, Texas had 8,203 megawatts of installed wind-power capacity.
¹³
But ERCOT, in its forecasts for that summer's demand periods, when electricity use is the highest, was estimating that just 708 megawatts of the state's wind-generation capacity could actually be counted on as reliable. With total summer generation needs of 72,648 megawatts, the vast majority of which comes from gas-fired generation, wind power was providing just 1 percent of Texas's total reliable generation portfolio. ERCOT's projections show that wind will remain a nearly insignificant player in terms of reliable capacity through at least 2014, when the grid operator expects wind to provide about 1.2 percent of the state's needed generation.
¹⁴

Given the data from the Global Wind Energy Council and ERCOT, it's clear that wind power cannot be counted on as a stand-alone source of electricity but must always be backed up by conventional sources of electricity generation. In short, wind power does not reduce the need for conventional power plants, a point that was underscored in early January
2010 when Britain was hit by a record-setting cold snap. At the same time that energy demand soared due to the cold weather, Britain's wind farms produced practically no electricity.
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