Comment A few useful statistics (Score 4, Informative) 332
This being slashdot, I expect the usual nonsense about "But electric cars just get energy from gas-burning power plants . . ." will start up immediately.
Here are some facts that I don't think anyone disputes. Absorb these, and then continue with the ranting.
Fact 1: Electric motors are more efficient than internal combustion engines. Run a gas engine at X watts for 20 minutes. Run an electric motor at X watts for 20 minutes. Afterwards, the gas engine will be hotter than the electric motor. Yes, it depends on the load, blah, blah, blah, but in the loads typically encountered by cars, the internal combustion engine loses.
Fact 2: The energy density of batteries has quadrupled in the last 10 years, mostly pushed by laptop and cellphone battery technology. Lead acid batteries have about 35 Wh/kg, while different variants of lithium batteries are in the range of 100 Wh/kg to 150 Wh/kg. Note that the cost of a lithium pack is substantially higher than that of a lead acid pack of the same capacity.
But don't worry, zealots! There are still lots of other things to debate! Does every family of four really need TWO cars with more than 100 mile range? Was Carl Pope of the Sierra Club being blackmailed when he endorsed hybrid SUV's in the latest issue of Green Car Journal? Would you cry if someone gave you a lithium-ion-powered Tzero for Christmas or other nugatory tradition? Can putting a 500 W solar panel on a car that consumes 15 kW at highway speeds make any difference? Will people ever stop suggesting that putting generators on the wheels of electric cars is a good idea? Am I really as much of a tool as I seem?
Have at it, boys!
Here are some facts that I don't think anyone disputes. Absorb these, and then continue with the ranting.
Fact 1: Electric motors are more efficient than internal combustion engines. Run a gas engine at X watts for 20 minutes. Run an electric motor at X watts for 20 minutes. Afterwards, the gas engine will be hotter than the electric motor. Yes, it depends on the load, blah, blah, blah, but in the loads typically encountered by cars, the internal combustion engine loses.
Fact 2: The energy density of batteries has quadrupled in the last 10 years, mostly pushed by laptop and cellphone battery technology. Lead acid batteries have about 35 Wh/kg, while different variants of lithium batteries are in the range of 100 Wh/kg to 150 Wh/kg. Note that the cost of a lithium pack is substantially higher than that of a lead acid pack of the same capacity.
But don't worry, zealots! There are still lots of other things to debate! Does every family of four really need TWO cars with more than 100 mile range? Was Carl Pope of the Sierra Club being blackmailed when he endorsed hybrid SUV's in the latest issue of Green Car Journal? Would you cry if someone gave you a lithium-ion-powered Tzero for Christmas or other nugatory tradition? Can putting a 500 W solar panel on a car that consumes 15 kW at highway speeds make any difference? Will people ever stop suggesting that putting generators on the wheels of electric cars is a good idea? Am I really as much of a tool as I seem?
Have at it, boys!
