I am impressed with the result. Using the planetary gear system that way is similar to an idea I have. But I still think it is an overly complex execution of a simple concept.
One of the comments to the article expresses my feelings perfectly:
It seems like they lost track of some design goals somewhere and increased complexity in many cases even where it was not needed.
" This configuration reduces battery drain at steady state, cruising speeds in a window ranging from around 30 mph to more than 70 mph (48 to 113 km/h), adding up to two miles (3.2 km) of additional all-electric range. "
OR...they could have used another .5kWh of the battery pack and gotten another 2 miles of range without adding all the cost/complexity.
Designing these types of systems requires engineers to make judgement calls and tradeoffs. It seems like whoever was leading this team was erring on the side of trying to squeeze every little ounce out of the system and may have ended up making the system itself too complex and missed the mark.
Impressive...but did it have to be?
Posted by: DaveD | October 20, 2010 at 05:50 AM
The original VW Beetle didn't have such a major impact because it of the efficient performance, it was the efficient design: Simple, easy to maintain, and inexpensive (i.e. less environmental impact to build).
I've heard some environmentalists say that the lowest environmental impact choice for a car is to re-build an older car instead of buying a new one. Not keep an old smog-hog running, but update it with modern components where possible. I feel electric car enthusiasts would be better served by a basic, simple design that could be mass produced quickly and widely. If a major auto company like GM produces the electric car version of the VW Beetle they will sell and all of the laughing would die away quickly as the public got past the unfamiliarity and novelty and realized how practical they are.
Get it out the door with a basic battery, or better yet have battery options. A modular system would allow that. A simple software update to a universal charging system would allow it to support any battery pack. In 5 or 10 years when the next generation batteries appear people will be able to upgrade and double or triple their range. The simple, efficient design of the base platform means that it will last a lot longer than typical. Over the total life of the car it will end up having significantly less environmental impact than a more fancy car with 20% better efficiency.
Total cost of ownership is what is killing the hybrids now. The systems are so complex they add too much to the cost of the vehicle and owners can't recoup the cost, even with $4 gas. Why hasn't the flywheel/starter/alternator on every car's engine been replaced with relatively low-power motor/generator like Dynastart? I've heard that in quantity the cost is comparable. Add just a little battery or ultra-capacitor storage and any car could gain 5% efficiency or more for almost no cost.