Are flex-fuel/hybrid vehicles and biofuels a scam?

Question

Whenever I think about what I learned in school regarding law of conservation of energy I can't help but wonder that these things are all just an expensive scam.

Answer 1

You're assuming that gasoline engine cars, as they are now, are perfect.  That is not so.  They are perhaps 20% efficient at best, and as they are used in cars today, less than that.

That leaves a lot of headroom for improvement before we have to start worrying about breaking any laws of thermodynamics.   A few points of comparison:

- GE's best power generating turbine is about 50% efficient.

- Electric motors are 90-98% efficient. (as evidenced by being able to drag freight trains around without needing more than air cooling.  

- Vehicle battery packs are 80-95% efficient.  

- Solar (PV) panels are about 3% efficient.  Mostly, they just get hot :(

- Solar-thermal collectors designed to get hot do much better. 10-20% efficient.

Now let's talk about biofuels.  The ground receives about 1000 watts of energy per square meter from the sun.  So there's no worry of going "over unity" on biofuels. Growing biofuels probably wastes 99% of the sun's energy.

One problem is the rampant use of petroleum in farming - for fertilizer, farm machinery, food processing (the "wet mill") and for ethanol, the distiller.  For ethanol, it's a sad picture.  Fossil fuel that would take a car 100 miles -- if diverted into agriculture -- will produce enough ethanol to take that car only 132 miles ;(   Barely worth doing.   Biodiesel is much more efficient, it will take the car 320 miles.  That's using current factory farming techniques, which could be vastly improved upon.  

Now what's a crazy scam is putting a windmill on the back of your car to generate power from your car's draft.   Or using your car's alternator to electrlolyze hydrogen to burn as fuel!  These are classic over-unity scams.

Answer 2

um no there not a scam cause in the long run they will help out with money and every thing

Answer 3

what do you mean a scam? The only reason that these cars get more gas mileage/cleaner is they use much more efficient types of engines. At best there cars are about 50% efficient.

Flex fuel is you can use ethanol witch is not more efficient. and hybrids use regenerative braking to be more efficient. And they use electric.

The law of thermodynamics does apply. :)

Answer 4

You’re probably right, since what ever company is providing the fuel can still jack up the price when ever they felt like it.  If America made a truly 100% flex-fuel car, that would be a great thing.  If you had more than 5 different fuels that could run a particular vehicle, that would create competition.  And as we know, competition helps to keep the prices down.

Answer 5

No.  The reason hybrids are an improvement is that they increase efficiency because electric motors are ~90% efficient.  At the moment flex fuel cars are pretty useless because we only have corn-based ethanol, but once we develop better sources like switchgrass which again will improve efficiency, flex fuel vehicles will be a decent option.