That suggests no counterweight. Solar power is going to be tricky.
Hmm. Guess you're right. Guess that's why you're RightWhale!
Think of the cable as the spine of the system. It stays stationary. The cars crawl up and down structures fixed to it, or are raised and lowered on their own much lighter cables, much like a regular elevator. A counterweight is probably mandatory, for dynamic as well as energy consideration, but it can be a returning car rather than a dead weight.