Sunday, May 27, 2007

How Green is the Wind?

I want to briefly address one claim made by wind energy promoters: wind power will help reduce CO2 emissions that contribute to global warming. Superficially, it makes sense that generating power from wind would reduce emissions from burning coal, but that is not the whole story. In order for this claim to be true, the total reductions in CO2 emissions obtained from commissioning a wind turbine must exceed those created by its fabrication, transport and installation.

In fact, the intermittent and unreliable nature of wind energy production does not permit conventional power generation plants to be taken off line, and can actually reduce their efficiency because they must now be fired up or down on a regular basis in order for the grid to utilize the unpredictable power generated by wind. Considering the small amount of power generated by a wind turbine, the net reduction of CO2 emissions in overall electrical power generation achieved through its operation can't be very significant, and could actually be negative in some cases.

The huge wind turbines currently used to harvest wind power each weigh 120 tons or more and are made of various metals and advanced composite materials. These materials must be either extracted from the earth and refined, or fabricated from organic materials or petroleum products, leading to the release of many tons of CO2. Much more CO2 and many additional greenhouse gases are released during the process of fabrication and every factory worker in the plant contributes even more during his/her daily commute.

Next, consider that these huge machines must then be transported long distances (in our case from Pennsylvania to Kansas) on very large trucks releasing many additional tons of CO2. Once on site, huge quantities of diesel fuel are consumed by earth-moving equipment in road and site preparation, quarrying and milling of rock, trucking thousands of tons of gravel, cement, water and rebar (itself made of steel that releases large amounts of CO2 during smelting) and by the massive cranes (also transported long distances) that are required to erect the turbines. Think about this and you will begin to understand why big oil companies are buying interests in wind power and seeking to promote it.

When all this is considered, you arrive at an estimate that each turbine must operate at full capacity for about seven years to recover the carbon footprint of its installation. However, even the most optimistic projections suggest that only about 1/3 of 'nameplate' capacity is achievable, so now we need more than 20 years of turbine operation just to break even on CO2. And how long are these things supposed to last ?

But its all green power from there on, right ? Nope. You still have to budget for decommissioning - thousands more tons of CO2 emissions from heavy machinery transport and operation during salvage and site restoration - unless you are willing to simply abandon the turbines once they are beyond repair. So it is preposterous to claim any CO2 reduction from wind power; if anything, the promotion of wind power in its present form (and at taxpayer expense) is simply increasing consumption of fossil fuels and accelerating CO2 emissions. It is also putting more money into the pockets of big oil companies while the leaders of our government get to 'greenwash' their electorate into believing they are actually doing something about global warming.

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