Commissioner Ervin, a Democrat, was born on November 18, 1955, in Morganton, North Carolina. He attended the public schools in Burke County, North Carolina, graduating from Freedom High School in 1974. He also attended Davidson College, where he received an A. B., magna cum laude, in 1978, and Harvard Law School, from which he received a J.D., cum laude, in 1981.

After becoming licensed to practice law in North Carolina in 1981, Commissioner Ervin entered private practice in Morganton, North Carolina, with the firm of Byrd, Byrd, Ervin, Whisnant, McMahon & Ervin, P. A., and its predecessors. While in private practice from 1981 to 1999, Commissioner Ervin represented clients in a variety of administrative, civil, and criminal cases before various governmental agencies, the North Carolina trial and appellate courts, and the United States trial and appellate courts for North Carolina. Commissioner Ervin left the practice of law to take office as a member of the Commission on July 2, 1999, and is currently serving his second term. He served as Chairman of the Subcommittee on Nuclear Issues and Waste Disposal of the National Association of Regulatory Utilities Commissioners (NARUC) from 2002 through 2005 and served as Chairman of the NARUC Committee on Electricity from 2004 to 2007. He currently serves as a member of the NARUC Electricity and Consumer Affairs Committees and the NARUC Task Force on Climate Policy. His current term ends June 30, 2015.

Commissioner Ervin has, at various times, been active in various bar-related and charitable organizations. He is a member of the First Presbyterian Church of Morganton, where he has served as an elder. He is married to Mary Temple Ervin and has two stepchildren and two children.