Why? Most people can do the math if they understand how losses in closed systems work. Particularly losses when converting types of energy to another type.
Electric plants run on coal, or oil (gasoline or diesel) for the most part. There are a few atomic ones, but they're rare and probalby only going to get rarer. Using coal, you burn 2-3x more coal to make the equivalent amount of power for a mile, than you do in gasoline. And coal is dirtier to burn than gas, not being refined you see. Why is this? Well, gasoline engines are far more effcient than a coal generator. Even atomic reactors are only 1% effcient. Gas generators are better, and closer to what you'd get in a car, but there are losses in making the electricity, then losses in using the electricity to move the car. You'll burn more gas to make electricity to run a car for a mile, than you'd burn to move a car itself a mile.
Each conversion of energy loses some of that energy. For a car it's gas into motion. The loss is heat. For a gas generator to electric car its: Gas into motion (losing heat), motion into electricty (losing heat again to friction), electricity into motion (losing heat to friction). More loss means you need more gas to do the same thing. Not to mention most gas generators are gas turbine generators. While the gas turbine engine can make more power per gallon than an internal combustion engine, the latter is far more effcient. One of the myriad of reasons gas turbine cars never went anywhere.
:thumbup:
Yes to all of the above, however, it is a little more complicated as electric motors are more efficient thus recouping some (not all) of the loss from the conversion of fossil fuels to electricity.
A gasoline engine is about 25% - 30% efficient, meaning about 70% - 75% of the energy converted is lost to heat and 25% - 30% makes it's way to actual mechanical energy. An electric motor is about 75% - 80% efficient (converted to mechanical energy) with 20% - 25% lost to heat.
The real problem we face is that we have spent the last 100 years developing an infrastructure that is reliant on a finite fuel source (fossil fuels). Ideally, we would create a new infrastructure that uses various passive forms to generate electricity; Solar, Wind, Hydro, etc. to support electric motor vehicles. I am not a big fan of Hydrogen, but look what the Scandinavians are doing with their Hydrogen Highway:
http://www.scandinavianhydrogen.org/, pretty cool, they use solar powered electrolysis to separate the hydrogen to be burned in their fuel cell vehicles.
A quick note on fuel sources and their average energy conversion efficiency to electricity:
- 20% for Solar Cell (non-polluting, passive, renewable)
- 35% for coal (polluting, non-renewable)
- 38% for oil-fired power generation (polluting, non-renewable)
- 45% for natural gas (clean, non-renewable)
- 50% for Wind Turbine (non-polluting, passive, renewable)
- 60% for Gas Turbine plus Steam Turbine (clean, non-renewable)
- 75% for Fuel Cell (Hydrogen) (by-products may be hard to deal with, renewable)
- 90% for Water Turbine (non-polluting, passive, renewable)
On another note, even if we got completely away from fossil fuels as a fuel source, we are still dependent upon it as a chemical compound for things like rubber and plastics (as well as other stuff), and for manufacturing purposes. Which most of our electric vehicles would need.
Don't get me wrong, I want an electric vehicle future (or some alternative, non-polluting, renewable resource), all I am saying is that it goes beyond what motor and fuel we choose...it's complicated
