YellowLite Visits the American Solar Challenge In Brecksville, Ohio

YellowLite visited the Cuyahoga Valley Career Center in Brecksville, Ohio to take part in festivities ushering in the start of the American Solar Challenge on July 29th in anticipation of the start of the race on July 30. The race is 1,975 miles long starting in Ohio and ending in Hot Springs, South Dakota. The event is for solar cars built by university students from around the country with a few participants outside America.

 

Solar cars can travel 40 mph continuously at peak sun without draining the batteries and therefore still be self-sustaining. The cars have a range of 150-160 miles in a day at full battery charge. Each car weighs around 400 pounds although one entry from the University of Minnesota weighs twice as much, 800 pounds. This was mostly due to the fact they designed their car to compete in an Australian outback race where they built a two-seater for the cruiser class.

 

When I asked each team how fast their cars can go, the answer was surprising. They can only go around 65 mph, although one team claimed they can get up to 90 mph. Because it is a road race and they are going on the highway for long stretches, the teams are required to drive in the right lane because of safety issues.

 

The panels for nearly all of the cars are from Sunpower and are around 22% efficiency. The panels have a trimmed-down, super thin coating to eliminate all excess weight. When I touched the panels with my finger for one team, you would have thought I was accosting the Mona Lisa. The reason is that the panels are very susceptible to damage. Even the slightest rock kicked up from the road can have drastic consequences and require serious repair or replacement. Another type of solar panel is called Gallium Arsenide. It is NASA-grade solar cells that are extremely expensive and have a high rate of efficiency. But there is a limit to how much you can install on each vehicle. The Gallium Arsenide is easily damaged so the drivers have to step carefully into the cockpit and not touch the panels at all, especially the Gallium Arsenide.

 

The most expensive portion of the vehicle is the array which can cost up to $100,000. The cars themselves are prohibitively expensive. The average cost for each of the vehicles is $200,000. The Michigan car is reportedly worth a million dollars. For most of the vehicles, the metal frame costs around $30,000. Each team has gotten plenty of sponsors and proudly displays them on the side. Without sponsorship, they simply would not be able to compete because of financing.

 

Different teams use different types of design. Most have the cockpit placed in the center of the vehicle while a few others have the cockpit offset to one side. Even the tires are all different and specifically designed for the car they are supporting. They are engineered for a lower roll resistance than normal tires so it takes less energy to roll them around inside the frame.

 

The cars are not built for comfort. There is no air conditioning, radio, or any modern accoutrements. Most teams use several drivers throughout the day because it can get hot inside and driving can be physically taxing. The entire car is a small cockpit with an aerodynamic design. When asked if it would be an advantage to have a physically lighter driver who would carry less weight, the answer I received was surprising. The weight of the driver doesn't matter. They normalize the weight for everyone to be 80 kilos or 176 pounds. If you weigh less than 176 pounds, they add ballast to the car to get you up to the required weight, so no car has an advantage in this aspect.

 

An interesting tidbit about the race is that there is a specific strategy for going around turns and going up and down hills. The drivers are instructed to coast whenever they can, especially going downhill, while accelerating a little sooner right before an incline. Several teams printed out topographical maps to anticipate how much energy they would need. 

 

So, who is going to win? The top three teams are generally believed to be Michigan, Minnesota, and Appalachian State. There is no cash prize, they are racing for pride and accomplishment. 

 

So what does this say about solar panels and electric cars? For one thing, since these cars have no other propulsion other than the electricity they produce from their solar panels, it seems to indicate it is possible to provide additional power while driving. Another thing that it shows is that these prototypes with their cells visible might not be so far off in mass production as electric vehicles will one day be common as gas-powered vehicles.

 

If electric vehicles are to become the dominant form of automobile on the road in a few decades, placing panels on them would be a brilliant way to provide power. How long does it take to charge an electric vehicle? Well, “to recharge a completely empty car battery from an ordinary 120-volt socket, the Chevy Volt plug-in hybrid would need 10 hours and the Nissan Leaf EV would need 20 hours.” This is a tremendous amount of time and it has to be reduced for electric vehicles to become mainstream.

 

The benefits of solar cars would be that they do not make any noise, they do not add any pollution to the environment, and can theoretically last for decades as the energy from the sun is free. The limits are that they require getting their energy from the sun and storing that same energy in batteries. In September of 2014 the first solar powered family-sized vehicle was introduced, winning the World Solar Challenge. The Stella, is the first vehicle made for road travel and can go 500 miles on a single charge. The Tesla Roadster can run 245-300 miles on an electric charge.