This adds a lot of mess. You'll need slip rings to bridge fixed power to the moving platform. Or if you are very brave, use a long lanyard, bidirectional motor, and a turns counter. Twist the lanyard exactly n revolutions, then unwind exactly n revolutions. Good luck with this scheme. Maybe it could last a month.

Battery might work, adding some weight and cost if you don't have one in your junk box. Most light strings assume 120V. (10 12V batteries or 77 D-cells in series? This will be fun to charge.)