This reminds me of the biology professor at a former school who said that we should have generators with fan blades attached to cars to generate electrical energy to charge batteries making the car more efficient. I told him that the fuel efficiency would be worse because "you can't get something for nothing and you can't break even." After a careful explanation of the dramtic increase in air resistance of the fan blades when you start letting current flow through the generator, bringing up Lenz's law, ohmic losses, bearing friction, he still didn't believe me. Then I handed him a Genecon, told him to turn it quickly and then I shorted out the connections. He STILL didn't believe me! If I had been the Dean, I would have banned him from the classroom.
He was Canadian; does that explain it? :)
________________________________________
From: phys-l-bounces@carnot.physics.buffalo.edu [phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of Bernard Cleyet [bernardcleyet@redshift.com]
Sent: Saturday, February 26, 2011 11:30 AM
To: Forum for Physics Educators
Cc: Sharing resources for high school physics; NorCal AAPT e-mail list; PHYSLRNR@LISTSERV.BOISESTATE.EDU
Subject: [Phys-l] another crackpot idea from the California legislative assembly
Comments/questions on AB 306 (Gatto): Energy: piezoelectric transducers: study.
This bill would require the Energy Commission to conduct research on the feasibility of generating electricity using piezoelectric transducers under major roadways as a renewable resource, by collaborating with the Department of Transportation to establish a pilot project that would employ piezo-based energy harvesting technology. The bill would allow the Energy Commission to expend the moneys in the Alternative and Renewable Fuel and Vehicle Technology Fund, upon appropriation by the Legislature, to implement this research as part of the Alternative and Renewable Fuel and Vehicle Technology Program. The Energy Commission would be required to report its findings in the integrated energy policy report adopted in 2013. These provisions would be repealed on January 1, 2015.
my post:
The proponents of this suggested method, evidently, aren't physicists. Physicists know that this is not a source of energy, but just a transfer of energy from gasoline that powers the vehicle to electricity in the roadway device. Such a method will decrease the efficiency of the vehicle by increasing the rolling friction. Think about it by answering the question, why do under inflated tires reduce fuel mileage, and visa versa?
bc
bc forgot to add: using gasoline to generate electricity directly would be more efficient than this crackpot method!