I worked very hard to find an investment that was a "pure play" in wind power, which turned out to be a very difficult thing to do since US Tax laws makes it financially beneficial for wind turbines to be owned by power companies. The result is that wind power developed by independent companies is typically sold almost immediately to power companies such as PSE. The one "pure play" I could find was the following:
http://www.vestas.com/Disclaimer: A relatively small chunk of my investments is in this company, a position which I bought as a "social investment" expecting not to make any money on it but its actually done pretty well. Please do not consider anything I have said here as a recommendation that you either should or should not own stock in this company. And I am deadly
serious when I say that!