Hydroelectric Power for Dummies

Converting the kinetic energy of falling water to electric power

Over the past couple of decades, thousands – who knows, perhaps hundreds of thousands – of reports have been generated that bemoan the poor STEM (science, technology, engineering, math) results of the average educational system here in the good ol' USA. No one had to tell us about it, though: we see it every day in the work of self-appointed freelancers. Take, for example, the thinly-disguised ignorance in the Sciencing.com post "How Does a Waterfall Generate Power?" courtesy of Lauren Vork.

We'd like to think that your average ninth-grade science student who tackled that question would manage to insert the concept of the conversion of potential energy to kinetic energy and perhaps even mention the word "gravity" somewhere along the line. Vork, on the other hand, parlayed her "music performance" degree into something entirely different; an "explanation" that included none of those words except energy (and she botched that). Vork opened by informing her readers that,

"Humans have long been harnessing the power of naturally flowing water in order to make life more convenient. Before the invention of electricity, river waterfalls were used to move turbines..."

We'd like to make the following corrections:

• Turbines are relatively new, having been invented in the early 19th century
• Electricity wasn't "invented," Lauren!
• Oh, and what other kinds of waterfalls are there?

But don't mind us, we're just scientifically pedantic as opposed to scientifically ignorant. Speaking of "ignorant," here's Lauren's attempt to explain the generation of electricity with a hydroelectric source:

"[The] standard electromagnetic generator [converts] mechanical energy (the energy of moving objects) into electrical energy. This is done through an apparatus which moves magnets around a conductor, generating an electromagnetic field that is then collected as electricity."

FWIW, Lauren, the energy of moving objects is kinetic energy... but what can you expect of someone who thinks that a generator is merely "an apparatus which moves magnets around a conductor" or that it works by "generating an electromagnetic field that is then collected as electricity"?

Wait, what... "collected as electricity"? WTF does that even mean??? This all comes from a scientific illiterate who thinks that the purpose of a hydroelectric dam is to "restrict the natural flow of a river into channels where the water will power turbines."  If Vork had even a taste of the concept of potential energy, she might realize that a dam raises the level of the water to create greater potential energy before channeling it through a turbine to generate electricity. Now, if we could just figure out how our Dumbass of the Day thinks that electricity is "collected"...

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