Freeman died on May 12, 2020, at a hospital in Reston, Virginia, after having a heart attack. He was 94, and was hospitalized a week before his death. News of his death was first announced by his daughter, Anita Hopkins. Freeman has authored several books, including "Energy: The New Era" (1974), "Winning Our Energy Independence" (2007), An "All-Electric America: A Climate Solution and the Hopeful Future (2016)" and an autobiography, "The Green Cowboy: An Energetic Life" (2016). Other books that contain his works include "Oral history of the Tennessee Valley Authority: Interview with S. David Freeman, March 30, 1984" and "Speeches by S. David Freeman" (1997). In "Winning Our Energy Independence", he wrote that there is the renewable energy needed to wean society from the Three Poisons: foreign oil, dirty coal, and dangerous nuclear power.