Where's An Electric Snowmobile When You Need One?
By Bill Moore
Posted: 08 Dec 2009
It's snowing... again.
I've cleared maybe 4 inches in the last 24 hours and another 6 inches or more is on the way over the next 24, but this isn't what got me to thinking about snowmobiles. It was Patrick Wheeler over at the University of Nebraska at Omaha who observed on my Facebook page that instead of putting sandbags in the back of my 1998 Chevy S10 to give it traction in the snow, an electric snowmobile strapped onto its bed would be even better.
I couldn't agree more, especially now that it looks like we're definitely going to have a "White Christmas" this year. But stop by your local outdoor recreational vehicle dealer and you won't find such an animal. Commercially, electric snowmobiles just don't exist, not yet.
But academically they do and the University of Wisconsin at Madison's BuckEV pictured above is the "Best of the Breed."
As I thought about Patrick's comment, I decided to do a little research. I knew Raser Technologies had developed an electrical snowmobile a couple years ago to showcase their Symetron motor technology. After demonstrating the machines feasibility, they shelved the project and moved on to fry bigger fish.
Then I also recalled that some universities had built a few for the SAE Clean Snowmobile Challenge. Initially conceived as a competition to build a better IC-engine snow machine in 2004, the competition added the Zero Emission category in 2008, drawing university teams from as far away as Alaska and Maine, as well as Canada.
Funded in part by the National Science Foundation, the goal of the program was to create a zero pollution snowmobile that could take researchers into pristine snow zones at Summit Camp, Greenland, a remote climate research center atop two miles of glacial ice. The clean snow zones allow scientists to record global pollution levels free of local contamination. Even humans walking into the zones are monitored by GPS. No petroleum-fueled vehicles are allowed in these critical areas, so an electric snowmobile makes imminent sense.
NSF set a series of performance goals for such a machine. It had to have an operational range of at least 10 miles (16km). It needed a top speed of 45 mph (70km/hr). Acceleration over 150 meters should be under 12 seconds. Noise levels had to be less than 78 dB, or about the level of normal conversation. A typical gasoline snowmobile generates 100 decibels.
The first generation version of Wisconsin's snowmobile far exceeded these goals. The 2008 unit achieved 19.6 mi (31.5 km) of range, had a top speed of 76 mph (122 km/hr), took only 8.3 seconds to cover the 150 meters and produced only 55 dB of sound as it did. Additionally, it demonstrated it had a drawbar pull of 254 foot-pounds (206 kgf); while weighting 691 lbs (313 kg). A stock Polaris IQ Fusion, the chassis the team used for BuckEV, weighs 466 lbs. (211.6 kg).
One of the more intriguing aspects of the Madison machine is that it uses a Delphi AC-induction electric motor sourced out of a General Motors EV1 electric car (where do these people find these gems?). The controller is an Azure Dynamics DMOC445LC. The team developed an innovative coupling system between the motor and tracks, the details of which are discussed and illustrated in a 2009 technical paper entitled, Refinement of a High-Efficiency Electric Drivetrain for a Zero-Emissions Snowmobile.
Batteries for the 2009 upgrade, which took not only the Zero-emission snowmobile title last March (for the second year in a row), but also beat out even the IC-engine machines, are 104 lithium-ion cylindrical cells supplied by Milwaukee Tools providing nominal system voltage of 364V. The cells demonstrated full performance down to +10° C. In real-world operations at Summit Camp, the team reports in their technical paper that..
Reduced power delivery performance is seen when cold, but very cold cells will rapidly heat up due to increased internal resistance, and 90% of normal power is available within 105 s of start-up (at 20 A discharge).While the BuckEV is capable of fast sprints, the team found that most of the daily trips at Summit Camp were short hops, most less than a mile, but the machine was used regularly and frequently, making some 72 trips in just a 10-day study period. Of the 57 days the machine was at the camp the summer of 2008, it racked up 212 miles (341 km). Many of these trips were cargo tows, often pulling sleds loaded with 1,500 lbs of payload. Tests demonstrated that modified Polaris could tow such loads between 5 and 10 miles before needing to be recharged.
It may not be until the next decade that snow-white machines like the BuckEV find their way to your local snowmobile dealer, mainly due to cost issues, but the it has clearly demonstrated that it's possible to compete with and often beat the best of breed gasoline-fueled models, while being nearly whisper quiet and pollution free. When that happens, the sport of snowmobiling will finally have a machine as virgin white and peacefully silent as the pristine environment into which their owners venture each winter.
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