Elevator design -no electricity supply? I hope someone can help me. I'm designing a building for uni that requires several lifts (elevators) which transfer bicycles and pallets vertically. My tutor suggested to look at energy efficient lifts. He mentioned that he had seen a lift, which movement was controlled by a weight being placed on another lift forcing one lift down and one lift upward. A counterweight system, that relies upon weight rather than a guy pulling on a pulley. If anyone knows of such a lift please can you direct me. It would be ideal for my design which is for a cycle delivery hub, whereby cycles unload and then collect new packages. I am aware of magnets but just wish to see if my tutors approach exists! Thanks in advance.