The Sun’s Energy Doesn’t Come From Fusing Hydrogen Into Helium (Mostly) It does undergo nuclear fusion, but there are more reactions and more energy released from reactions other than H → He. December 26, 2019science, spacehistoryscoper https://medium.com/starts-with-a-bang/the-suns-energy-doesn-t-come-from-fusing-hydrogen-into-helium-mostly-2476d69e83c