July 1, 2006

Scudder Parker's wind turbine sales tour

WCAX-TV reported from Hinesburg (Vt.) on June 27:
To talk power, Scudder Parker went to NRG Systems in Hinesburg, a company that manufactures wind measuring equipment used by wind power developers. ...

Parker supports wind development and thinks the state can get 15% of its energy from wind, he says that would require at least 100 turbines on ridge lines all over Vermont.

"I don't see it as a question of aesthetics I see it as a question of people recognizing wind turbines as we recognize church steeples and silos in barns as a part of something that is making our economy healthy and giving us choices as a state."
Vermont uses over 5,600 gigawatt-hours of electricity in a year. That's an average load of about 640 megawatts (5,600,000 megawatt-hours divided by 8,760 hours in a year). Fifteen percent of that is 96 megawatts. The wind power salesmen say the turbines will generate more than 30% of their capacity in a year. The facility in Searsburg, however, generates only around 21% of its capacity each year. The national average output as reported to the federal Department of Energy's Energy Information Agency is 27%, but that apparently does not count out-of-commission turbines. Twenty-five percent (1/4) output is therefore a more realistic, though still generous, estimate.

That means that 384 (96 × 4) megawatts of wind power capacity would have to be installed to produce an average of 96 megawatts, or 15% of Vermont's electricity. That would require 256 330-ft-high machines like the four proposed in East Haven, or 192 400-ft-high machines like the 26 proposed in Sheffield and Sutton -- much more than "at least 100" which Parker promises.

They are obviously a lot taller and more intrusive than silos and church steeples (in fact, they're a lot taller than the Statue of Liberty, base and all), they are necessarily sited prominently, their jumbo-jet-sized rotors sweep vertical air spaces of 1-1.5 acres, and they are lit by strobes day and night.

For practical planning purposes, even more would be required. Because generation occurs only within a certain range of wind speeds and the rate of generation is cubically related to the wind speed between the "cut-in" and "rated" wind speeds (typically 8-30 mph), wind turbines generate power only two-thirds of the time and at or above their average rate only one-third of the time. And since the production responds only to the wind, it rarely correlates with user demand. Even with sufficient excess capacity from other sources on the grid to balance its intermittency and variability, the effective capacity of wind is therefore typically assumed to be a third of its expected output.

So 1,152 megawatts of wind -- 576 to 768 machines -- would be needed to reliably provide 15% of Vermont's electricity.

The absurdity goes beyond the outrageous scale for such little benefit, because if all of those turbines were actually producing power at once, most of them would have to be shut down, since base load plants can't rapidly ramp off and on.

wind power, wind energy, wind farms, wind turbines, environment, environmentalism, Vermont