Another example of a niche startup opportunity in the generally mature wind power industry, Knight & Carver performs inspections, maintenance and repairs on wind turbine blades.

Knight & Carver was founded in 1997, and has grown its territory to cover the United States, Canada, Latin America and Europe. The company, which is based in Howard, South Dakota, also has a marine services division.

The $12 million investment was provided by Global Environment Fund, a private equity firm.