While I am not an expert in Wind Technologies, I do believe, wind energy is a very viable Sustainable Energy Initiative. With massive scaling, transmission costs even at $6M/mile becomes a fraction of the total costs, and my understanding is in high wind areas, the costs are now in the 8- 10cents/kWh range with today’s technology. As Ken points out if the new 5MW turbines come up and they further tweak their technologies, their prices/kWh should further go down.
As to your question about the carbon footprint wind technologies have currently have a very low carbon foot print after considering cradle to cradle lifecycle (actually slightly lower than solar as it stands today) .
There has been a fairly deep study done by Stanford University and California PUC commission to show that if wind and solar are very complementary as the 4-5 years study showed most wind generation is in the night and solar generated energy during daytime. Their report contends that wind and solar can meet 70% of the electric energy needs of California without significant investments in transmission and storage.
To me what can be an ideal scenario is if we can have Wind, Solar (their biggest issue is to drive their costs down aggressively further, and massive scaling under a long term structured policy is the only way to achieve that) and Nuclear (get the fear and perception issues resolved through massive education campaign, instead of trying to sweep concerns under the carpet) complemented by Hydro and gas turbines to manage the valleys and shortfalls can be a the dream scenario.
In parallel, if USA as the largest source of coal reserves, find an economically viable solution for lowering the carbon footprint, that can be a worthwhile cause too.
What I’d like everyone to start thinking about is how to grow the Sustainable Energy Initiative Pie 10,000 -20,000 times more from the current usage. SEI is an emerging market and is a blip on the radar screen right now. We should consider all energy sources as potential complimentary resources as long as they meet the SEI criteria. Our traditional mindset forces us to always think about a mature market/ limited resources scenario where it is completely logical to think of getting a larger slice of the pie. Right now the pie is really tiny for SEI and it makes total sense to band together and grow the pie. We can worry about getting a bigger slice of the pie when the market has grown 10,000 times more and starts to mature.