The American Solar Challenge (ASC)
A Synergy of Solar Power and Batteries
Dedicated to Team Building and Racing
Photovoltaics/Automotive/U of MO 030829

The University of Missouri -Rolla celebrates a victory in Claremont, California after being first to cross the finish line in the 2003 American Solar Challenge.  The team set a record for the U.S. solar car racing by finishing the 2,300 mile race in 51 hours, 47 minutes and 39 seconds.  This is a record time, beating the 2001 record by more than four hours. (Photo is courtesy of the Department of Energy’s website on the American Solar Challenge.)
Double junction Gallium Arsenide solar cells and Lithium-ion polymer batteries work together to power the University of Missouri - Rolla (UMR) team to win the 2003 American Solar Race. The 339 pound vehicle, The Solar Miner IV,  with 1500 Watts of power won this 2,300 mile national race by driving from Chicago, Illinois to Claremont, California in 51 hours, 47 minutes and 39 seconds.

Solar Power - A gift from the sun

Within a solar array, energy from the sun  is collected by photons in the solar cells.  The energy is turned into electricity  which travels through the power trackers that maximize the amount of energy needed to run the car according to how much is being collected and the status of the batteries.  The team was fortunate to have Gallium Arsenide double junction cells made by Spectrolab.  Douglas Carroll, a UMR engineering professor, said the cells were about 22 percent efficient.  These cells were the most expensive part of the car, running in the ballpark of tens of thousands of dollars.  The cells were provided by Spectrolab at a deep discount; the cells were rejected for use on satellites because of the very  rigid  requirements for each application.  However, these ‘rejected’ cells are still of high quality and are much more efficient than standard silicon terrestrial grade cells.

Full grade Gallium-Arsenide  cells can run into the millions of dollars and are used in specialized space applications.  Will some of the newer cells with higher efficiencies (35%) be used in a solar race soon?  Probably not; they would be unbelievably expensive. As one person stated on the American Solar chat website, “You can’t afford them.  However, Warren Buffet could maybe cover his car roof, but not the hood and trunk.  And, then he’d be broke.”  (Comment found on website, “Stuff that Matters - News for Nerds” in comments on UMR winning the American Solar Challenge.)   
The 2003 American Solar Challenge started in Chicago on July 13th and followed historic Route 66 through Illinois, Missouri, Oklahoma, Texas, New Mexico and Arizona and ended in California. Dedicated in 1926, the road served as a major thoroughfare to the West. Although  the original Route 66 was formally decommissioned in 1985 and has been replaced with newer highways, including Interstates 40, 15 and 10, it is still considered the “Mother Road.”   The route following this historic highway makes it   the longest solar race in the world.  +    

Power storage - Lithium-ion polymer batteries

The battery pack , comprised of 460 individual batteries, weighing approximately 460 pounds, is   arranged so that the output is 100 Volts.  The batteries  have the ability to source over eight kiloWatts.  Although the precise cost of the batteries is unknown,  a figure, found in  “Facts and Questions”- a published paper about the American Solar Challenge 2003, listed  a price of $10,000  for a set of Lithium-ion batteries.  The UMR  team  stated that the Solar Miner IV, UMR’s winning solar car,  could run over 250 miles on a full battery charge with no solar power from the sun.

Vignettes of the race - following UMR on the race route

This is not a race where the winning team initially took the lead, sat on their laurels  and easily crossed the finish line  in first place. Challenges were encountered but the team was prepared to focus all its energies and resources to  meet the needs for each day.

On the first day, the  team had problems with their motor and had to replace it at  a pit stop in Springfield , Illinois.   Therefore, at Checkpoint 1, they were running third  behind Minnesota and Waterloo. Although the new motor worked just great, the UMR team was still  19 minutes from the lead at the end of the first day.  

On day two from Rolla to Albuqurque, the UMR team decided they would have to have to set a target speed of 55 m.p.h. to get ahead.  Waterloo had a problem, so the UMR easily gained some miles on this  team which had been ahead the previous day. As for Minnesota, the team had chosen  a  cruising  speed of 50 m.p.h., so the UMR team was able to pass .  In  reflecting on this day, one of the team members made the   comment - “This was the last time we would see the rear end of any solar car during the race.”
The University of Minnesota placed second in the American Solar Challenge.  They also used Gallium Arsenide solar cells on their arrays; their array peak rating was 1000 Watts (only 1 1/3 horsepower.)    For power storage they used Lithium polymer batteries manufactured by Kokam.  (Photo is courtesy of the Department of Energy’s website on the American Solar Challenge.)

From Edmond to Sayre, the teams encountered some of the worst roads.  A crack in the body of  Solar Miner IV widened and the UMR team had to look for a plan to repair the vehicle. The  team was fortunate to locate an alumni in Amarillo who was able to weld the vehicle.  

The drive from Amarillo  to Tucumcari went very well.  However, during regular checks of the vehicle, one of the team members spotted a couple more cracks in the chassis, so another welder had to be found when the team arrived in Albuquerque.  

The course from Albuquerque to Gallop provided  no problems and the team pushed on to Flagstaff.  Clouds began to form, so it was imperative to keep ahead of  this  sun-shielding front.  The team pushed on to Flagstaff with sun shining on the arrays   and completed  the  435 mile trek  for the day.  

Being on a fast track to win the race, the team crossed the California State Line and encountered  temperatures on the desert as high as 117 degrees F.  They reached Barstow with each team member drenched  with  perspiration, but somehow the heat was bearable. UMR was in the lead and the closest competitors, Waterloo and Minnesota, were about two hours behind.The rest of the trip proved to be just as successful. The Gallium Arsenide solar  cells and Lithium-ion polymer batteries performed magnificently.  UMR  kept their lead and placed first, with Minnesota, second and Waterloo, third.  Fourteen months of designing, building and racing the car had resulted in a dream come true.  Spending all of each team member’s free time on the race for many months  proved to be a world class experience.      
Racing - a great tool for teaching application of skills

The stated purpose of the ASC is not to bring solar cars to consumers but rather to inform the public about alternative energies and encourage young engineers to think about energy efficiency in their selection of careers.

For the team members themselves, the Race takes on a greater  significance - life long goals of working together.    As one of the students said  on the UMR website, “The Team is like a small business, what we do involves interaction with peers, faculty administration, and world corporations, so communication is key.  Learning how to communicate effectively helps in many facets of life.  We have the opportunity to travel for testing, fund-raising and the race.... We are a team, so we have to learn to get along, keep on track with our goals, and share responsibilities through good times and bad....(But) knowing that you are a part of something that could make a huge impact in the future is fun!”  

Enhancing the experience across America

No longer  is solar racing left to a few students at the Universities.  High school students are beginning to get involved. This July, a 1,500 mile solar car race was held for high schools wishing to participate in the program.  The Dell-Winston Challenge began in Rock Hound, Texas and concluded in Cocoa, Florida at the Florida Solar Energy Center.  The winning vehicle, the Sundancer ,was designed and built by high school students from Houston, (not Texas) a rural town in Mississippi  with a population  of 3,903.  This is the third year that this team won the race, which is the largest, longest running high school solar car race in the world.

The Sundancer was completely powered by solar energy.  This 722 pound, 17.5 feet long and 6 foot wide vehicle  traveled at a top speed of 64 miles an hour but averaged 23.1 m.p.h.

A spokesperson for the Houston team, Sherrie Gail Springer, said, “It’s hard to describe how much this program means to each of us.  We really feel like it’s helping us be better students, and also helping us get ready for the future.  We’ll remember this experience for the rest of our lives.” (Ed Note: No extensive term paper could ever offer such a memorable learning experience.)

Beyond being a phenomenal experience for those involved (students, faculty, supporters and sponsors) in  the American Solar Challenge and the Dell-Winston Challenge, it is hoped that these  races will be the catalyst for companies, engineers, teachers, students, and communities to look at ways they can personally become involved in a environmental project which will lead to clean U.S supplied energy for the future.

There will always be some who say, “We don’t have the time,” or “this is way out of our price range.”  But, fortunately, there are individuals who have persevered, found monetary support and    joined with others to build a team; they  have  kindled life into learning and given students a hands-on taste of the future energy requirements for a better tomorrow.  Each individual (or company or organization ) makes the choice to give (or not give) the next generation a taste of  the excitement and challenges for what it takes to bring the  green  technology in its infancy today to  full fruition tomorrow.