The hits just keep on coming for the wind sector, and that should further highlight the growth potential for this sector with investors. For years, critics of renewable energy in general have said that the sector needs to stand on its own two feet and not rely on government subsidies. Thanks to advances in materials and technologies, the wind sector is showing signs that it is growing up, a bit smarter and ready to take on natural gas.

In recent weeks I've pointed out that despite the wind production tax credit (PTC) set to expire at year-end, companies like Italy's Enel Green Power (OTC:ELPSF) and Germany's Siemens (OTC:SIEGY) are moving forward with wind projects and innovative turbine technology here in the U.S. In fact, Siemens recently announced it is the supplier of the largest onshore wind turbine deal in the world (448 turbines), an order from Warren Buffett's MidAmerican Energy to be located in Iowa; according to the company's website, Siemens "has nearly 5,000 wind turbines installed at wind farms throughout the U.S., including Hawaii, Iowa, Kansas, Nevada, North Dakota, Oregon, Pennsylvania, Texas and Washington State."

Now Siemens is back in the news with plans to provide 3.5 megawatt offshore wind turbines for the 130-turbine Cape Wind Project. Additionally Siemens will be providing maintenance on the turbines for 15 years, so it's obvious the move to support wind is a long-term affair even without PTCs. Continued positive momentum for wind investment should bode well for turbine makers such as General Electric (NYSE:GE) and Emerson Electric (NYSE:EMR), the parent of SSB Wind Systems. I'm also a fan of American Superconductor because they are making the brains of the wind turbines. Additionally, since rare earth materials are being more widely integrated into blade technology, investors may want to keep Molycorp (OTC:MCPIQ) on the radar as well.