Tag: Fuel comparison

Nuclear fusion releases millions of times more energy per kilogram than the chemical reactions that power our cars and homes, giving a clear winner in the question of what fuel releases the most energy. However, the answer is complex and depends on the specific type of energy release being considered.

A single gram of matter, if fully converted to energy via Einstein's equation ($E=mc^2$), contains 89.9 petajoules of energy. In a matter-antimatter annihilation reaction, the total energy released per gram of *antimatter* is twice this amount, making antimatter the most energy-dense substance known. However, this is a theoretical peak, with more practical sources also offering incredible power.

While fat provides the most energy of any dietary nutrient at 9 kcal per gram, this is dwarfed by nuclear power. But what truly releases the greatest amount of energy per gram? The answer lies far beyond dietary calories and even nuclear reactions, at the very limit of physical possibility.

Fats provide more than double the energy of carbohydrates or proteins per gram, with 9 calories per gram. The answer to which gives the maximum energy is nuanced and depends on the application, contrasting the biological needs of the human body with the needs of industrial power and advanced propulsion.