Electric elliptical machine without wires

An innovative elliptical device I bought from a gym, in perfect condition with no defects. It operates without being plugged into an electrical outlet; as soon as you start using it, it generates electricity and powers the screen. The device is identical to those in gyms and can support weight over 100 kilograms. Reason for selling: I no longer need it. The device is large. Its original price, if I'm not mistaken, might have been 10,000; I purchased it from someone who took it from a gym.