I was going to comment about how incredibly misleading the first graph is; because the scales used make it appear that production almost perfectly matches capacity — yet, production is only about 20% of capacity. However, the article covers that point quite thoroughly, so I won’t be making any comment.*
* Well, except for the comment I just made above.**
** And the comment I just made above about commenting.
The graph and the first few words of the article tell the story best.
Even though the production tax credit began in 1992, windpower didn't take off until 2001. So something is in play besides the tax credit. What is it?
The price of natural gas. Look at the graph.
The first natural gas shortages in 2000-2001 and the spike in nat gas prices at that time set off the first segment rise of the graph. Until 2005.
In 2005 the graph line(capacity) gets steeper which reflects the shortages and price rise of gas caused by Katrina. Until 2007.
In 2007 the graph line increases gets steeper again to reflect that the price of natural gas had started following the price of oil(going up).
The author is not well informed when he speaks about nighttime wind power in Texas. Because Texas generates more power from nat gas than from coal, wind is substituted for nat gas at night.