Fusion: 340,000,000 MJ/kg Fission: ~83,000,000 MJ/kg Fossil fuels: ~24–44 MJ/kg Batteries: <1 MJ/kg Solar: ~0.0015 MJ/m³ (as delivered to Earth) Wind: ~7 MJ/m³ (typical power density in air at 5m/s wind) The best renewables deliver orders of magnitude less energy per mass or volume than fossil fuels—and millions to billions of times less than fusion. Fusion is on the order of 1,000,000x more energy per mass than fossil fuels. That’s why fusion wins: orders of magnitude more instead of a linear progression of more access to power.