Tuesday, August 25, 2009

Electricity != Electrons

I first heard it about a decade ago on a local TV news broadcast story about an increase in Electric Utility rates:

"Soon you'll be paying even more to get those electrons"

The idea behind this statement being:
Electricity = Electrons, therefore when we pay for Electricity we are paying for the Utility company to reach into it's bag and hand us more electrons.

It's too bad that it's the wrong concept and is just not true.
I chalked up that incident to general ignorance of the TV news staff (nothing uncommon here, I remember the same staff reporting once that they were amazed to discover that "The radar guns that the Police use emit some kind of a wave !").

Time forward to this last weekend.
I was listening to an NPR podcast and heard it again:
"Paying for Electricity means paying to get Electrons"



In direct current (DC) such as what we get out of a battery, there is a one way electron flow that corresponds to the electric energy that we get from the battery.

But in our houses we get alternating current (AC), alternating meaning that the polarity of the 'electricity' in the 2 poles of the plug is constantly switching back and forth from positive to negative (many times a second). So actually, rather then moving in just one direction, the Electrons are constantly moving back and forth in the wires. We're not paying to 'get' electrons, we're actually paying for the energy that's related to the electrons constantly being 'given and taken back'.

While electrodynamics is a complex specialty subject that one could make an entire career out of, I think they taught us these basic ideas about AC current in the 3rd grade. They also taught us about the concept of the Electromagnetic Spectrum in the 3rd grade as well (Radar is a wave !).

What's with education these days ?

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