Other than this post on the subreddit, I haven't really seen or heard mention of water hydroelectric elevators (basically, closed-loop hydraulic elevators that use a water-based fluid instead of oil) anywhere, even though the post alleges that some places still installed them into the post-WWII era (1950s-1970s).
Why is this? Were they a terrible idea? Did all of them get modernized to oil, or are some of them still chugging along on water-based fluids? And could one get a water-hydroelectric passenger or service elevator built for them (presumbly by an independent) in this day and age?
(Part of why I ask this is that the carwash people have been busy tinkering with non-oil-based hydraulic fluids using water/glycol or water/polymer mixes, and it seems that going to water-based fluid would get rid of the need for oil separators and possibly even shunt tripping, both of which have attendant headaches of their own.)