Dude, his name clearly indicates that he's somewhere in Africa, and from his previous posts he has stated a couple times that power is not only cheap, but massively subsidized by the government. This seems like one of the least wasteful uses of an African hydro subsidy I can think of, since if as he says he is using it for a lesson for some advanced students, this could be a great idea. I'm going to assume this is somewhere in sub-sahara, as internet is super expensive down there. If so, think of all the horrible multinationals that are using ENORMOUS amounts of that wasteful, subsidized power to further fuck up the landscape and subdue the local populace with shitty, dangerous mining and logging jobs. There is absolutely nothing wrong with using power that would be wasted on planet-rape anyway to get a few bitcoins to use to teach some students both economics and comp-sci.
This sounds like an excellent idea, even if you get very few bitcoins, because I think it would be a really good teaching tool. The whole concept of bitcoin is so fascinating, especially to someone who is already interested in computer technology.