Proponents of industrial wind energy facilities often argue that the electricity they generate will improve the air quality – thereby alleviating human health impacts associated with air pollution. The air quality benefits of wind energy are often heralded by developers and boosters, but such claims are supported by wishful thinking and not reality.
These false notions indicate a lack of understanding of the programs and success of the Clean Air Act – perhaps the toughest and most effective environmental law enacted by Congress. It also reveals a lack of appreciation as to how little electricity is generated by wind farms during the summer months, when the demand for electricity is greatest and when “code red” air pollution alerts mainly occur.
The alerts are due to ozone, formed on hot days mainly from nitrous oxides (NOx) – pollutants which are emitted by power plants but spewed more abundantly from automobile exhaust. Under the Clean Air Act, the Environmental Protection Agency has long maintained a cap-and-trade program to put a ceiling on and regulate power plant emissions of NOx, as well as another major pollutant responsible for “acid rain” – sulfur dioxide (SO2). EPA determines how many pounds of NOx and SO2 can be emitted annually by power plants in our region (i.e., the “cap”), and then divides up the total quantity allowed for each into “pollution credits.” EPA then apportions these credits amongst the power plants – allowing owners to buy or sell the “credits” via an established market system (i.e., the “trade”) in which their value is set by demand and supply.
EPA’s cap-and-trade strategy uses market forces to limit and curtail air pollution emissions of power plants, and it has been amazingly effective. A report by the U.S. Public Interest Research Group documented that power plants operating within Pennsylvania reduced their emissions of NOx by 26 percent between 1995 and 2003, and they also had an 8 percent decrease in SO2 emissions during the same period. The cap-and-trade program of EPA created economic incentives for power plant owners to operate their facilities at higher efficiencies (getting more BTUs per unit of fuel) and to burn cleaner fuels (e.g., natural gas vs. coal).
There is a widespread belief that the electricity generated by wind turbines will back down a commensurate amount of generation from other power plants in the grid, thereby saving some fossil-fuel from being burned – thus preventing some air pollution which otherwise would be emitted due to combustion of the “saved” fuel. While logical, this scenario doesn’t reflect reality and ignores EPA’s successful cap-and-trade program.
The generation of electricity by wind farms will not significantly reduce the air pollution emissions from power plants because the cap-and-trade program allows any unused pollution credits resulting from the fuel savings due to wind-generated electricity to be traded – enabling other power plants to burn more fuel and/or use cheaper but dirtier fuel.
Essentially, EPA’s cap-and-trade program creates a “zero-sum” game which prevents wind farms from causing a meaningful decrease in the emissions of NOx and SO2 from power plants.
In addition, during summer months the wind farms installed in our region operate at only a fraction of their generating capacity due to the low average speed and intermittency of winds during this time of year. For example, from July through September of 2005, the 63 huge wind turbines (94.5-MW total) installed at the Waymart and Meyersdale wind plants generated so little electricity that their combined output could be matched by only 16-MW of a coal-fueled power plant or 14-MW of a typical nuclear power plant.
Even worse, the expected generating capacity of wind farms during heat waves – when ozone alerts are more likely to occur and would be most serious – is probably going to be far lower than their summertime average.
An often-posed rhetorical question asks if “smokestacks” are preferable to wind farms – a false choice. Thousands more wind turbines are coming, yet smokestacks will persist and likely increase in number. Wind turbines will not qualify as credible substitutes for building future power plants since they cannot be counted on to produce electricity when needed. They also will not result in the retirement of any existing power plant given the ever-increasing growth in demand for electricity in our region.
To match the commonwealth’s rate of growth in electricity production via wind energy would require the annual construction of about 700 of Gamesa’s 2-MW wind turbines – resulting in the conversion of 100 miles of ridge top per year into industrial wind farms!
DAN BOONE of Bowie, Md. is a professional ecologist and natural resources policy analyst.
24 August 2007
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