A roller, in particular track roller or a carrying roller for use in a cableway system is formed with a cylindrical tubular piece that is located radially on the inside, two annular bearings that are located radially outside the tubular piece and at an axial distance from each other, and a roller body that is located radially outside the annular bearings. The roller body is formed of a track ring and two flanged disks located to the sides thereof. The roller includes an annular electric generator which is located within a cavity surrounded by the roller body and the two annular bearings.