Brilliant, World-Saving Idea VS. Universal Laws Of Physics. Oh, Dear.

Here’s the thing: this won’t work. The idea in question is called MotionPower, from New Energy Technologies. NET won’t tell anyone yet how it works, just that they have a working prototype designed to “harness some of the kinetic energy being generated, and wasted, by moving cars”. Regardless of how they claim it’ll work, it won’t. Kinetic energy is the energy of motion, so wasted kinetic energy is stuff that’s moving but not getting anywhere, just as wasted heat is hot but not actually being used to heat stuff. If you think about the idea of a car moving but not getting anywhere, the only option is burning rubber. Whether spinning out, drifting, or just pushing the envelope, that is the only example of wasted kinetic energy that a car has (which may explain the blatantly undisguised Audi R8 in their graphics), but that is not going to help in day-to-day city driving. Allow me to explain.

One of the most basic laws of physics is that you can’t create energy, you can only convert it. Another one is that you can never ever have a 100% efficient conversion of one kind of energy to another. That means that to get energy from the motion of a car, the electric energy is converted from the kinetic energy of the car which comes from the heat energy of a combustion engine which comes from the chemical energy of gasoline. So essentially you’re generating electrical energy from burning fossil fuels. This sounds familiar…

It turns out that the only forms of wasted energy from a car are the following:
– heat from the engine (can’t do anything about that)
– friction in the air (aerodynamics try to help with this)
– kinetic energy of the exhaust (that’s what a turbocharger uses)
– friction on the road (harder tires help there)
– heat from the brakes (regenerative braking)
– heat from the transmission (nothing to be done)

Not normal kinetic energy. No matter how you break it down, all they’ve done is create a generator that is powered off of the fossil fuels in the car already, just way less efficiently. And a 20-year-old who failed physics can see that. Well done.

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