The Bonneville Power Authority service area has more than 4,000 MW of wind energy capacity installed. They also provide a web-based information service that is updated every five minutes that reports on the service area load, thermal generation, hydro generation, and wind generation.
Here is a picture reporting those numbers for the period from Jan 16-Jan 22, just a few minutes ago.
Please note the magnitude of the wind generation and the steady output required from the thermal generation in order to supply the loads that did not disappear just because every wind turbine in the entire area decided that they would call out together for a week’s vacation.
Remember this picture when you read a study from Mark Z. Jacobson about how distributing wind over several different geographic areas will result in reliable power because the wind is always blowing somewhere. The question he never addresses is how long the extension cord might need to be in order to connect to “somewhere” else.
Update (posted Jan 27, 2014 at 04:20) Here is an image of the same chart as above for the period from Jan 21 – Jan 27 2014. It looks like the wind in the Pacific Northwest has extended its vacation by another week.
Update (Posted Jan 30, 2014 at 01:45) The wind in PACNORWEST has returned from vacation, feisty and ready to rock and roll. Take a look at the wind power ramp on Jan 29!
Update: (Posted Feb 5, 2014 at 06:30) It looks like my statement about wind’s return from vacation was more correct than I thought. It has been rocking and rolling this week. Imagine the effort from the grid managers required to provide stable power when such a large generating source comes in and out so irregularly.