Mike Carrell wrote:
The discussion about wind is a lot of blade-waving [instead of hand-waving]. Wind is variable, no guarantee capacity will be available if the conventional system sags.
That is incorrect, as the article points out. Wind is not particularly variable over large areas. That is to say: because modern weather prediction is so good, and because wind farms are spread out over large areas, the extent of probably variations in wind power can be predicted with confidence days ahead of time, and with even greater confidence and precision hours ahead of time. This allows the network managers to plan dispatching of other generators and scheduled maintenance of both wind turbines and conventional plants well ahead of time, with confidence. If the forecast shows the wind will not blow hard next Wednesday, they schedule a wind turbine for overhaul. Alternatively, if the forecast predicts high winds, they may plan to close down the coal plant for maintenance instead. This works so well, wind turbines are almost as predictable as conventional, fuel-powered generators.
Also, as the article pointed out, when the wind is not as high as predicted, or when one wind turbine fails and has to be taken off line, the drop off is usually not as severe as it is when a fuel-powered generator fails. In this sense, wind is actually more reliable and predictable than fuel-powered generators. When fuel generators fail they drop off abruptly and completely, without warning.
The virtue of wind in that case is that the generators are relatively small and distributed.
Actually, they are now becoming huge. A single generator is 1 to 3 MW, which is small, but many wind farms are now hundreds of megawatts, as large as a good sized coal or gas turbine.
- Jed
