I see the 2 shown are 2 man-power each. (See the treadmills and rails are the "power" end). Considering each "bucket" - or partition segment of the water column - is a litre or so - That's 1 kg mass - being raised 1m., and there are about 20 buckets (bottom row) = 20kg.m of work done in however long it takes. Maybe 50 seconds? (200Nm/50secs = 4W). It is difficult to generate 10W of electrical power (from some College experiments) continuously for 1 person (We tried a 10W generator on a bicycle for 24 hours, <15 mins per person!). But slowly, the 2 men per lift could do it enough - but I bet the leakage losses are large. However, much easier to make than an Archimedes screw!
K2
Some 40+ years ago, when I was much younger and in great physical condition, I traveled to Peru with a tour group to hike a portion of the Inca Trail leading into Machu Picchu. The highest point on the Inca trail reaches nearly 14,000 feet (4200 meters) and has many sections exceeding 70 degrees up; it is considered second in difficult hikes only to Mount Kilimanjaro. Those of us on the tour group hiked the trail each day carrying only a light weight day pack containing a few energy bars and a single canteen of drinking water, while our porters carried all of our tents, food, sleeping bags, cooking utensils, etc. Each porter carried nearly their own weight in camping supplies, and they nearly sprinted up the steep trails, leaving we tourists in their dust. Each day, I was in awe of their physical abilities. I considered myself to be in very good condition, but these local farmers, working as porters for a little extra money, made me, and everyone else on the tour group, look like 98 lb wimps.
My point: it's been my observation that the physical endurance of people living in 3rd world countries where they perform hard labor every day just to survive, far exceed the abilities of even the best athletes of 1st world countries. From what I witnessed these porters do, they could operate those pumps for hours on end.
