[jgjot-singh]

Perhaps the trains could partly be passenger trains, costing amusemant park rates.

Then collected money could eventually pay off the cost of construction, and eventually maybe even offset the maintenance cost.

If nothing else, it would certainly boast the advantage of being more fun than water storage.

[fho]

Ideally have the transportees walk up the hill by themselves, summer sledding style. That way you are by some strange definition guaranteed to be net positive ;-)

[fortyrod]

I think you are on to something here. Make all elevators in hi-rises down-only and all stairwells up-only. Convert falling excess desk-jockey blubber into usable electricity while lowering rate of CV disease and generally improving fitness. Downside is probably a lot of BO that didn't exist before.