The hybrid cars mass-marketed today do not use any electricity from the grid. The official EPA mileage gives a good picture of how much gasoline they save, though certain kinds of drivers get worse fuel economy than that both for hybrid cars and for conventional cars. The best state-of-the-art hybrids save on the order of 40-50% of the gasoline compared to an equivalent conventional car, but cost $3,000 more to make or buy. The national security benefits of cutting US gasoline needs in half would be huge, but at $3/gallon for gasoline, the fuel savings are not that much more than the $3,000 cost.
But several non-US car makers are moving very quickly
towards introducing plug-in hybrid cars, which would allow consumers to use
electricity from the grid to replace gasoline, at their choice. IEEE Spectrum,
July 2005, gave some important information. A Toyota Prius
with a 9kwh battery added has an all-electric driving range of 32 kilometers.
On average, that replaces half of the (already reduced) gasoline requirement
with electricity. Industry estimates suggest that the $3,000 cost of hybrids is
$1200 power electronics and $1800 batteries -- but
The biggest benefit from plug-ins is security in case of a shortage, rather than gasoline saving per se. The ability to drive to work or to shopping in case of a total gasoline shutdown or unaffordable gasoline limits the possible economic damage. Still, the savings in consumer fuel bills should be large. I do not believe every word at
which is an advocacy source -- but I tend to believe their claim that the electricity which replaces a gallon of gasoline would cost less than $1. I believe it because little engines which burn gasoline to make electricity on-board a car are less efficient in their use of fuel than the big 24-hour coal and nuclear plants which work at night (when plug-ins would mainly be recharged) and because the cost per Btu of coal or nuclear fuel is a lot less than the cost of gasoline.
In total, then ordinary hybrids will cut fuel bills 40-50% compared to regular cars, while the coming plug-ins will cut gasoline 70-75% and fuel bills by a factor of three, and provide extra security, even if there is no further progress in batteries beyond what China has today -- all at a cost of about $3000 extra per car.
The charge-up would mainly be at night, imposing no cost on
electric power grid transmission capability. Electric generating capacity needs
to be increased, but that does not depend on the
The near-term option to reduce gasoline dependency by 75% is
by far “most of the game” today in improving the security of fuels for cars. It
is already well underway, due most of all to people in
For example – there is no reason at all why hybrids cannot
be “GEM” fuel flexible. See the other papers on the web site for why this is
important – especially to
Hybrids on the market today vary greatly in their EPA mileage benefits, their efficiency, and cost. This is due to a great variation in the level of the underlying technologies. R&D will be a crucial aspect of advancing all players in this market.