Is wind so unrelialbe as to not be an option?

One side of the global warming argument argues that renewables are too unreliable, particularly wind to be counted on in an energy mix and that wind is a waste of money.  Is that true?

First, the anti-AGW folks argue over at WattsUpWithThat:

"Wind power at most has a 30% utilization factor (and I’m being generous). MidAmerican Energy’s stated 20% wind capacity (actually, its 20% “renewables”, which includes hydro and biofuels, but you probably knew that) works out to well below the the magic grid stability number of 10%, above which wind power would destabilize the grid."

One energy company in Iowa, owned by Berkshire Hathaway, seems to be showing that is untrue.  MidAmerican states:

“At the end of 2009, MidAmerican had available nearly 7,200 megawatts of generating capability: approximately 52 percent fueled by coal; 21 percent natural gas and oil; 20 percent wind, hydroelectric and biomass; and 7 percent by nuclear. Production costs at our coal-fueled generation stations are lower than regional and national averages. The company has majority ownership in five of the six jointly owned coal-fueled generating stations in Iowa.”

How much of that is wind? 900 MegaWatts of 7,200 or 12.5%.

MidAmerica just announced an additional 593 MW of wind, for a total of approximate 1600 MW:

http://midamericanenergy.com/wind/news.aspx

This takes their wind amount to about 20%.

The point is, doing renewables can be done economically, or I highly doubt Berkshire Hathaway would be doing it. Again, look to real data and not to internet chat or biased sources, go look for yourself and do the math.