Cognitive Gear (post: 1377831) wrote:I'm curious about this. The light research I have done in the area showed a rather large difference in cost between the two, with electric coming in significantly cheaper. Since I've only done light research, I'd love any insight you could provide.
(warning: wall of text ahead.)
The usual mistake is in calculating the two systems by different measures. Gasoline has x joules per gallon or whatever measure you choose and therefore can be equated to y kWh, and so people use that to equate so many gallons with so many kWh and then find electricity cheaper than gas.
This would work if you could run an (lossless) extension cord back to your house no matter how far away you drive, but that's not how you are going to use it. You're going to charge up a battery, then run your motor off the battery. There is a big loss there.
There is also a big loss when you use the gasoline in an ICE (internal combustion engine). The loss from ICE to wheel is about the same as the loss from EM (electric motor) to wheel, but the losses inside the ICE (how much energy goes to mechanical work vs. how much is lost to heat) is different than the loss in the EM (how much battery power goes to mechanical work vs. how much is lost to heat). I can't remember which is better, but I do know that the loss from battery to EM multiplied on the loss from meter to battery while charging is somewhat higher than the loss in gasoline energy in the ICE.
It used to be considerably higher, when EVs depended on lead-acid batteries and traditional motors, which is how gasoline motors put EVs out of business around the beginning of the 20th century. However, newer battery technologies (most Hybrids and EVs today use nickel MH batteries) and new EMs (generally rare-earth permanent magnet motors) have dramatically decreased the losses and changed the game. At this time the game is slightly in favor of the EVs until you take back what they lose for being heavier, at which point it is apparently about even.
The thing is, it is really hard to make these comparisons with certainty, because of wide variations in performance between various gasoline engines and and between various electric motors, and how they tend to be used as well. The guy who goes out and buys an EV today is often very green-conscious and not shopping for a Hummer or BMW, but something very low-impact that looks a lot like the little Isettas that meter maids and the occasional oddball drove when I was a kid (google it and read up.) (I shouldn't say 'oddball' too loudly though. My aunt Laurie had an Isetta.)
The equivalent gas vehicles mostly don't exist, although a few products like Smart are starting to close that gap. Still, not a lot of apples-to-apples comparisons are available, so a lot of the discussions are based on the estimated performance of paper designs that only exist in auto company design departments.
