Seems like I'm seriously late for the upvote-party here, this post seems to be really undervalued.
The "number 1" at the illustration already begs for a proper discussion long time before deploying anything. Children being used as a source of energy?
Already before reading the rest of the article, I'm a bit torn between "that will never work out" and "right, why not?". Children do indeed spend a lot of energy during play. Make the pumping activity sufficiently fun, and the children will indeed pump. Appeal to the competitive instinct can also be used, like having some measurement on how many liters of water was pumped during a five-minute period, the children can try to beat each other on the fastest pumping as well as beat their previous records.
Some people may scoff at the idea of "child labour". Then again, the Wikipedia article very clearly states that the problem with child labour is when it "deprives children of their childhood, interferes with their ability to attend regular school, and that is mentally, physically, socially or morally dangerous and harmful". As long as the work is playful, fully volunteer, educational and the child doesn't take time off from school for doing the work, I have no problem with that.
Adults too, in some parks (at least in Norway and Russia) there exists public exercise equipment, that potentially could have been used for harvesting "free" energy.
If this really can be utilized as a profitable source of energy (i.e. as compared to alternatives - like putting up some solar panels or a diesel engine), someone probably would have already thought of it before. At least the energy-source-part of the pumping system ought to be thoroughly and properly field-tested before building the rest of the pumping system. And even if it theoretically could be possible to put up equipment that harvests energy from playing children, the idea of doing it through a roundabout seems obviously flawed.
The fun part of the roundabout is the momentum, the lack of friction, and that children with limited force and limited energy input can get the heavy thing spinning quite fast, and that it will continue spinning. Sometimes playgrounds can be found where an the roundabout has become old and worn, and has significant friction. Children will probably try to play with it for a short while, but it's not that interesting to play with a roundabout when the energy is just disappearing.
On that photo above with two ladies "playing", there is also a perfectly working diesel or petrol engine standing right behind which could relatively easily be utilized to power the pump.
Hey, thanks! Yes, I was quite proud of this post, even if it didn’t get a payout as high as some of my others.
Ha! We have a rule of thumb in public health, if you have to google the definition of Child Labour then there is probably an issue with your intervention!
Yes in theory it’s a nice idea but that’s where this story should have ended. Someone should have sat down with a pen and pencil and done the maths or perhaps listen to the local communities and ask them what they wanted/needed. I always say that this is a story that teaches us to be skeptical, but we have to then do the hard work of not becoming cynical because of it, it’s a hard line to walk sometimes.