Skip electricity. That doesn't matter until you can make reliable turbines with copper and magnets. Go to steam power first. It can move things. Which will speed up delivery of copper and magnets. But also teach them to plant trees. Every tree removed to smelt and power a steam engine needs to have three more planted. You could start greening the Sahara before umit even starts collapsing. "he sure had this steam thing figured out. I guess we will forgive him for all these useless trees".
Yes, electricity would be magic for medieval (and prior) people. Spells trouble for you.
But no, Steam... the principle was known and seldom used by ancient greeces and egypts already, but they couldn't really utilize it, because metallurgy wasn't there yet.
And Sahara was almost green 1000+ years ago, lots of oases.
Boil water in a closed system that uses steam to move a paddle on the inside that is on the same shaft as a wheel on the outside. That's the basics. Everything else is just variations on the theme. The higher the pressure the faster it goes and more torque you get.
Nah, for a first step implementation in stationary applications, you can have a steam machine run an open circuit. Steam expands, performs work, exits through a valve. Just keep the water tank filled. Less efficient, but it would work. The return loop is an optimization for the next stage :)
For better efficiency the steam should be used twice, in a high pressure circuit first and on its way back to the boiler through a low pressure circuit.
Without a printing press, which would increase the levels of literacy, and allow sharing knowledge orders of magnitude faster, there was no indication that a kettle could ever outperform a hundred men or a few dozen horses.
I'd say it depends on the person. I'm sure there are some that would majorly change the course of history and then some that would get killed within an hour
The problem with this is that you assume that wood is the best fuel source for steam. Very quickly you would realize that coal is far more energy dense than just about anything except nuclear fission. Planting trees is still a good idea though, but wood as fuel is utter shite on any large application.