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Saturday, July 23, 2011

Winds of Change

When the words "free energy" come up in automotive circles, there are two general responses.  They are either "turbos" or "hybrids."  Each of these fits the bill as a turbo uses exhaust gases to "create" more power from a motor that is smaller than its naturally aspirated counterpart and most hybrid systems capture heat from brakes which would otherwise be wasted.  The problem occurs when these circles of thought collide.  Turbos are generally regarded as go-fast hardware while hybrids are used by tree huggers and green peace activists.  However, I think I've found a solution!




No, mounting wind turbines to the tops of cars is not a feasible idea.  However,  putting one in the car could do a world of difference.  Warning: Nerdy Ramblings ahead!

Hybrids as we know them only generate electricity while under braking.  Considering the legal speeds that the general population is allowed to go, this means there is a very short, finite amount of time to harvest energy through the brakes mainly because Prius drivers travel at half of those legal speeds.  In addition, the fuel mileage figures for hybrids are better in the city than on the highway yet hundreds of thousands of miles are needed to offset the extra cost of a hybrid system.   So that Prius driver who keeps circling the block is really trying to justify spending a premium on a hybrid, not looking for a parking space.


This is where that wind turbine and turbocharger mumbo jumbo come into play.  Here are the basics of how a turbo works.  Exhaust spins some fan blades.  Those fan blades are attached back-to-back with another set of fan blades that blow fresh air into the engine to make power.  Now get rid of that fresh air side (compressor) and slap on an electric generator which, in its simplest, is a magnet and a coil of wires.  To make electricity, one spins inside the other, pushes electrons around, and creates a current.  At this point, you're probably saying,"but Danny wind turbines are huge and cars aren't."  Well, thankfully, electric generators follow Faraday's Law which follows:

ε=B*l*v

This formula states that the EMF, or electric potential, is equal to the magnetic field multiplied by the length of wire and the velocity of the spinning component.  Now compare the huge windmills that power towns to something about the size of a softball under your hood.  While the magnetic field and the length of wire will most definitely be smaller, turbos can spool at speeds of up to 150,000rpm.  Also, let's remember we're powering a portion of a car's needs and not an entire town. 


Here's where it all comes together.  A small turbocharger is constantly being spun by exhaust gases.  The infamous "turbo lag" occurs when a turbo is too large to be optimally spun by exhaust flow.  This means with proper sizing (and isn't everything about proper sizing?) the electric generator that is connected to the turbo will spin constantly as long as the engine is running.  In turn, this means that electricity is always being produced from the waste gases of the conventional motor.  This free energy could supplement power needs on the highway and allow an engine to work at a lower rpm.  Additionally, the hybrid benefits in city traffic are not sacrificed either.  With the engine still running when coasting or braking to a red light, the energy produced then is not used and can be stored in a battery pack for later consumption like when said light turns green.

I know this sounds like a lot of catering to the hypermilers and Whole Foods customers but as an enthusiast this system also has potential for the lead-footed hooligans amongst us.  Let's not discount the conventional turbocharger altogether.  There could be the possibility of adding that electric generator to the top of the compressor since the compressor and generator only need a mechanical connection with the impeller rod to spin.  With this configuration, a relatively large turbo could be fitted for top end power while the low rpm lag is taken care of by the electric torque from the generator.  Voila!  Big displacement power in a small, fuel-efficient package.


While I sat here contemplating this technology and patent papers, Mitsubishi's R&D department is a few years ahead of me.  They have developed the MET83MAG which they call a generator-integrated hybrid turbocharger for use on bulk carrier ships.  The first of these systems goes into production on a commercial carrier this year.  As you'd imagine, this is a bittersweet discovery.  Bitter for my bank account but sweet because the technology is actually viable.  As an added bonus, the MET83MAG was developed by Mitsubishi, the same company that said their technology-laden Lancer Evo would become a hybrid in the future.  If this is what they mean,  you may see my Evo XI at a Whole Foods near you.

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