May , 2009
So we all talk about electric cars and electric motorcycles and electric scooters as “green” technologies. But does the simple fact that they’re electric guarantee that they’re green? Not necessarily. I recently watched an episode of “30 Days” on Hulu that was about coal mining. Fifty percent of our electricity currently comes from burning coal! So half of the electricity we’re using to power these alternative vehicles also comes from coal. And it’s true that we have cleaner ways of burning coal than we used to. However it’s still far from what most people would consider “green”.
But besides the pollution that’s caused by burning coal, the “30 Days” show highlights the cost in people’s lives to mine coal underground, and the cost to land to mine coal via strip mining.
It really brings home the idea that, in the engineering world, everything is a trade-off!
May , 2009
April , 2009
Zero Motorcycles just released their first street bike, the Zero S Supermoto. See here for the full article. It is more expensive than its gasoline competitors, and has a shorter range, but on the other hand you never, ever, have to visit a gas station, and it’s quiet. Zero has been making all electric dirt bikes for a while, but this is their first street bike.
Then there’s Tesla Motors, who has been selling their Roadster for several months, and is currently working on their follow-on vehicle, which will be an all electric sedan. But Tesla, much as I respect what you’re doing, please stop saying you’re the first mass produced electric car.
I was on the GM EV1 project for two years. (Apparently, the few that are left are now in a museum. Doesn’t that make me feel old!) I was in the structures group, and I recall, early on in my time at GM, going through a “skunkworks” exercise to clarify and define the assembly process. We were pulled away from our offices and the interruptions of phone calls and people coming to our cubicles, and set up in a church of all things. We amused ourselves by calling it “going to church”.
During this period, which was originally planned to be two weeks, but turned out to be more like two months, we tore apart the vehicle structure and went over and over the entire process of the structure assembly. My group, the “release engineers”, worked hand in hand with the manufacturing engineers throughout this process. We thought carefully through every step, and every workstation in the plant. And in turn, these process changes drove design changes that improved the structure.
We were optimizing every workstation to be able to handle 5 jobs an hour. Now from the point of view of the rest of GM, where a speed of 60 jobs an hour is normal, this is very slow. But on the other hand it isn’t hand building either. We leaned heavily on our manufacturing engineers to think in new ways and to do what really made sense for the speed we were dealing with, and that ultimately improved both the design of individual parts, and the robustness of the final structure.
At the time I was involved, the plan was to make 80,000 over a period of three years. I think in the end far fewer were made, because the market at that time couldn’t support that number. But regardless, the vehicle was designed to be mass produced, and shouldn’t be considered a hand built vehicle.
One final note about electric vehicles. There is the idea out there that electric is so much cleaner than fossil fuels. And it can be. But we all need to keep in mind that an electric vehicle is only as “clean” as the method to create the electricity was. It’s possible to have a very polluting coal plant, for example, creating electricity. (I haven’t looked at the data recently about where our electricity comes from on average; perhaps that can be the topic of a future post.) However, it is certainly true that it’s easier and cheaper to control emissions when you’re doing so in a stationary location rather than a vehicle. Several concerns, like how much would it weigh, or how it would perform in a crash test, simply go away and thus simplify the problem somewhat.
All in all, electric vehicles is something that I’m going to keep watching!