October 30, 2006
Sustainability: The Little Engine That Could
MIT's pint-sized car engine promises high efficiency, low cost. By injecting a little bit of ethanol during the compression stroke of a regular 4-cycle ICE, these researchers have managed to reduce engine knocking. That enables them to increase the compression ratio (and/or turbo charging the incoming air), thereby increasing the efficiency (and power) of the engine. By shrinking the engine down to the old power levels, they again make it more efficient - they claim the net effect is a 20-30% efficiency gain and an engine half the regular size. But it still costs more, because you'll need extra high-pressure fuel injectors and other infrastructure. Read on for some thinking about the bigger picture here...
It reminds me of an older post of mine The Six Stroke Engine, but this works on a different principle. In theory you could combine the two ideas. Combine with electric hybrid technology for another boost... you can see how these ideas team up to make a really efficient car. But is all that complexity really necessary or ultimately beneficial?
The bigger issue here of course is that you've still got the same fundamental internal combustion engine technology - with all of it's disadvantages, most notably that you're burning fossil fuels! Thousands of little explosions per minute is not a "smart" way to move anything around, and all of the stuff that we're doing above looks increasingly to me like the epicycles that were added in ever greater layers to the Ptolemaic system of astronomy. There is a better way: electric cars.
It's funny how much can change in a few months - when I wrote that post about the six-stroke cycle in March of *this year* I honestly thought that it might be a technology which would see practical application on a wide scale. But I see now that neither that technology nor this one are every likely to see much use. The inventors say that in "5 years" they expect to see some on the road in vehicles (probably Ford - their research partners). But realistically 5 years from now electric is going to be taking over. Gasoline will be something like $5/gallon, and batteries will be improved enough to get a 200 mile range from a $5k pack... Would you rather "fill up" your car for $5 in electricity, or $95 in gasoline/ethanol? Economics will drive electric cars forward while the ICE becomes increasing seen as barbaric. Thousands of tiny explosions per minute! What a strange way to move yourself around...
