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 China now (for Oct. 2007) sells 10kwh batteries for $2000, and it seems likely that new plug-ins will offer this big increase in gasoline-independence for little more cost than today's hybrids, but only from non-US manufacturers. It will be a major challenge to help US manufacturers keep up and stay in business, because of the R&D gap here, involving batteries, power chips and systems issues.

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

http://www.hybridcars.com/blogs/power/ford-keen-interest-in-phevs,

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 Middle East, and is already an issue on the national agenda, solvable but in need of new R&D to reduce future costs.

Additional Comments:

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 Asia who understand what is at stake. But we could be moving faster, and we could be doing more to make this a win-win proposition for the entire world.

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 US auto makers and companies which sell liquid fuels.

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.