Great River Energy is an electric transmission and generation cooperative in the U.S. state of Minnesota; it is the states second largest electric utility, based on generating capacity, and the fifth largest generation and transmission cooperative in the U.S. in terms of assets. Great River Energy was formed in 1999 when Cooperative Power Association and United Power Association merged. Great River Energy owns or co-owns more than 100 energy transmission substations in the region. The companys system also includes more than 500 distribution substations. Great River Energy is a not-for-profit cooperative that provides wholesale electricity to more than 1.7 million people through 28 member distribution cooperatives in Minnesota, covering roughly 60 percent of the state. The company also owns transmission lines in North Dakota and Wisconsin. Great River Energys headquarters are located in Maple Grove, Minnesota. The facility includes a 160-foot-tall (49 m), 200 kilowatt NEG Micon M700 wind turbine (visible from Interstate 94), and a 72-kilowatt solar array at ground level and on the rooftop. The building uses approximately half the energy of similar-sized buildings constructed using standard construction techniques, 40 percent less electricity for lighting and 90 percent less water than standard corporate campuses. The company has occupied the Maple Grove facility since April 2008. In October 2008, the headquarters building became the first building in Minnesota to attain LEED Platinum certification.