Friday, June 18, 2004

A brief explanation of why industrial wind plants don't work

The biggest problem with large-scale wind-powered electricity generation is the grid. A home system can work well because the fluctuating output (even in the windiest places it is highly variable) can be regulated by batteries or flywheels, and another source (the grid or a gas-powered generator) is tied in to kick in when need be. This is the model where larger systems work in isolated villages, too.

But industrial-scale wind plants designed to supply the grid do not work well, even where the wind is superb. The grid is meant to respond to demand, constantly modulating the various suppliers to match the demand exactly. Wind plants respond only to the wind, forcing the more controllable "conventional" plants to change their output in response to wind production as well as grid demand. And the need to respond within seconds to a drop in wind production requires a plant that runs more inefficiently than one that could run if the grid didn't have to cope with the fluctuations of significant wind-powered sources. That is to say, wind farms may actually cause more fossil fuel burning.

The huge turbines designed for the grid can't work without electricity from the grid, either. They produce on average 25%-35% of what they are capable of, but they are using electricity (apparently free) 100% of the time.

And a problem about sites with good steady strong winds is that they are too windy. The turbines can't handle strong gusts and automatically shut down (typically around 55 mph). So "good" sites turn out to be very little more productive than less windy ones.