I will beging working as a wind developer after graduating from UT in May. In doing my preliminary research for my Master's thesis, I stumbled upon a white paper that discusses the central issue that my thesis will examine: how has introducing wind power into the ERCOT grid (i.e. the Texas grid) impacted wholesale electricity prices (and ultimately the prices paid by the end consumer).
It turns out that, contrary to wind opponent claims that developing wind power actually increases the power price on a given power grid, wind actually brings down the clearing price of electricity by offsetting the most expensive generators. Studies of the German grid have shown this to be the case, and I will be doing some simple modeling to try to estimate the effect in ERCOT.
The paper is worth a look. It can be found by clicking here.