SunEdison, Inc. is a renewable energy company headquartered in the U.S. In addition to developing, building, owning, and operating solar power plants and wind energy plants, it also manufactures high purity polysilicon, monocrystalline silicon ingots, silicon wafers, solar modules, solar energy systems, and solar module racking systems. Originally a silicon-wafer manufacturer established in 1959 as the Monsanto Electronic Materials Company, Monsanto sold the company in 1989.
It is one of the leading solar-power companies worldwide, and with its acquisition of wind-energy company First Wind in 2014, SunEdison is the leading renewable energy development company in the world. In 2015, SunEdison sold off its subsidiary SunEdison Semiconductor, marking the completion of SunEdison, Inc.'s transition from a semiconductor-wafer company to a dedicated renewable-energy corporation.
Following years of major expansion and the announcement of the intent – which eventually fell through – to acquire the residential-rooftop solar company Vivint Solar in 2015, SunEdison's stock plummeted and its more than $11 billion in debt caused it to file for Chapter 11 bankruptcy protection on April 21, 2016., eventually emerging in December 2017 as a restructured, smaller, private company.