The Exelon Pavilions are a set of four solar energy generating structures in Millennium Park in the Loop community area of Chicago in Cook County, Illinois, USA. The Northeast Exelon Pavilion and Northwest Exelon Pavilion (jointly the North Exelon Pavilions) are located on the northern edge of the park along Randolph Street. The Southeast Exelon Pavilion and Southeast Exelon Pavilion (jointly the South Exelon Pavilions) are located on southern edge of the park along Monroe Street. The pavilions provide sufficient energy to power the equivalent of 14 star-rated energy-efficient houses in Chicago. The Pavilions were designed in January 2001 and construction began in January 2004. The South Pavilions were completed and opened in July 2004 and the North Pavilions were completed in November 2004, with a grand opening on April 30, 2005. In addition to producing energy, three of the four pavilions provide access to the park's below ground parking garages and the fourth serves as the park's welcoming center. Exelon, a company that generates the electricity transmitted by its subsidiary Commonwealth Edison, donated $5.5 million for the Pavilions.