Here's a notable graph from the Texas ERCOT Monthly System Planning Report that shows anticipating wind capacity additions. It is hard to believe that power demand in the lone star state will grow much faster than these additions, since a 30% capacity factor is a reasonable rule of thumb. This shows that capacity additions have been very low for five years, and are expected to ramp up drastically in 2014 and again in 2015. At a 30% capacity factor, this would yield 1,100 additional MW of output in '14, and another 1,025 MW in '15. That would absorb about 2.5% in total load growth per year in ERCOT, and thus leave little for NG and other electricity sources. (The intermittency of wind is a separate and significant issue influencing the mix of other generating resources.)
