The crown prince and princess of Denmark and Colorado Gov. Bill Ritter attended the ceremony.
The two factories in Brighton a wind turbine blade factory and a nacelle assembly plant valued at $290 million were announced in August 2008.
The plants are expected to be fully operational in 2010. The blade factory will employ about 650 people and the nacelle plant will have about 700 employees, Vestas said.
Vestas opened its first U.S. turbine blade factory in Windsor in March 2008. That facility has since been expanded, for a total value of about $100 million. Its also building a $250 million plant in Pueblo that Vestas says is the worlds largest factory to manufacture the towers that hold the wind turbines aloft.
Vestas, based in Randers, Denmark, manufactures and sells wind turbines used to produce electricity.
Crown Prince Frederik André Henrik Christian, and his wife, the Crown Princess Mary Elizabeth, are visiting the United States to emphasize Danish-U.S. cultural and historical ties as well as on renewable energy and energy efficiency.