So this week is probably exactly the nightmare that I keep referring to for wind power. The overall capacity factor was up slightly from last week but only because of a large peak that occurred between the second and third days.
The power output went from almost nothing to over 900 MW in the period of a day and then dropped rapidly back down under 200 MW. Then it bounced back up and down for a number of days before it finally dropped back down to almost zero again by the end of the week.
Imagine if you were relying on wind power for 900MW of electricity, it would only be able to provide anywhere near that amount of electricity for a short period of time this last week. The rest of the time, the difference would have to be made up by coal or natural gas. But you can't just turn coal and natural gas on and off whenever you want. While the wind power is running, the natural gas and coal furnaces have to be kept hot so they can resume operation as soon as the wind dies down.
So you're burning fossil fuels anyways. So sure, you could build enough windmills with the capacity to replace a nuclear reactor.. but really, what you are replacing that reactor with is coal or natural gas 70% of the time.
Capacity Factor: 25.60%
Minimum Output: 15 MW
Maximum Output: 947 MW
Figure 1: February 24th - March 2nd Actual Wind Power