Got put onto an excellent data set from @eljmkt_nemlog on wind electricity production in Australia, when I was trying to answer the question "how often/or long is it since Australia had zero wind generation in the NEM?" Many public commentator bone-heads will say things like "what do we do when the wind doesn't blow!"
But does this actually happen? I wanted to know. We've been adding wind to the grid since 2007, does the wind actually stop blowing? and how often?

A story about an engineering assignment I did in about 2003.

4th year mechanical engineering students were given a task of making a pump and generator from scratch, to demonstrate on a two resorvoir system at uni. Two tanks, one 3m up. Pump water up, make electricity down. Uni provided a little electric motor with shaft which could work as a generator as well. The winning team would be the "best round trip efficiency", best ratio of energy spent and energy returned as electricity