Ener-D
Enerdy, known as Momentum in the Japanese anime, is a form of energy in Yu-Gi-Oh! 5D's. It is generated by the ultimate energy generation system that keeps spinning to generate this system. Enerdy is the major source of power in New Domino City that makes the technology for Duel Disks and Solid Vision
However according to Rex Goodwin the first Enerdy system existed within Satellite inner grounds. Where it was activated by the Momentum Investigation and Development Section 17 years ago, despite that the system control's were imperfect at that time.
In the English anime its name comes from energy, but replacing the G with a D, which stands for dueling. The change may have been due to the fact that in English, the term momentum refers to the product of a body's mass times its velocity, which is completely different to energy.
