Coal or Nuclear Power: Which Produces More Energy?

Nuclear power and coal both help supply electricity in the United States, but they differ sharply in the amount of fuel needed to generate it.

The key distinction is energy density: how much energy can be released from a given quantity of fuel. Nuclear fuel contains far more usable energy per unit of mass than coal, allowing a comparatively small amount to produce a large amount of electricity.

Coal-fired stations generate heat by burning coal, while nuclear reactors release heat through the splitting of atoms. In both types of plant, that heat is used to produce steam that drives turbines to generate electricity.

Because coal has a much lower energy density, coal-fired plants require substantially more fuel by weight. That difference also affects the scale of fuel transport, handling and storage needed to keep stations operating.

Nuclear power therefore comes out ahead when the comparison is energy produced from a given amount of fuel. The total electricity generated by a particular plant, however, also depends on its capacity and how long it operates—not simply whether it uses coal or nuclear fuel.