Why do gas centrifuges use less energy than gaseous-diffusion plants?

Gas centrifuges are significantly more energy-efficient than gaseous-diffusion plants because they do not rely on the high-energy requirements of forcing gas through porous barriers.1

In gaseous-diffusion, uranium hexafluoride (UF₆) gas must be repeatedly diffused through porous membranes to achieve enrichment, a process that consumes vast amounts of energy. Conversely, gas centrifugation utilizes high-speed rotation to separate isotopes based on mass differences; the heavier ²³⁸UF₆ molecules concentrate near the outer walls, while the lighter ²³⁵UF₆ molecules collect near the axis.213

Furthermore, modern gas centrifuges often operate within evacuated chambers to eliminate air resistance. By removing this friction, these systems can achieve the high rotational speeds necessary for efficient separation with relatively little expenditure of energy. Because of these operational advantages, gas centrifugation has largely supplanted gaseous diffusion for uranium enrichment.41