Can Piezoelectric Materials Help Offset Fossil Fuel Consumption?

Piezoelectric materials are those that, when physically deformed by an external force, produce small amounts of energy.  Here’s an article that suggests that pavements constructed of these materials could be used to offset the burning of fossil fuels in the generation of the electricity we use.

As usual, it all comes down to costs, in this case, the prevalent cost of electricity from competitive sources, the cost of the material itself and the capacity factor, i.e., the fraction defined by the amount of energy actually generated divided by the amount of energy that could potentially be generated in ideal circumstances if it were happening 24/7/365.

I don’t know exactly how to do the math, but in most imaginable cases, I’d have to suspect that the CF for piezoelectricity would be miserably small, as a given piece of pavement isn’t getting pounded by foot traffic every millisecond of every day.  I would think that the entrances to train and subway stations in huge cities would be about as close as one could come.

Maybe someone else knows more about this than I do. I seem to recall that frequent commenter Glenn Doty wrote something on this not too long ago.

One might ask: OK, why not build roads out of this stuff, since the force exerted by a car tire is so much greater than that of a human foot? The answer lies in the first law of thermodynamics, i.e., that when it comes to energy, there is no such thing as a free lunch. If the car does work, the car slows down, albeit microscopically, and thus needs additional fuel to keep moving.

Of course, the same principle applies to people (think of running on sand), but this effect with piezoelectric materials isn’t noticeable, and even if it were, we need the extra exercise in any case.  The extra work we do comes from the chemical energy in the food we eat, and most of us would be happy to shed a bit of that.