World Solar Challenge
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The World Solar Challenge or the Bridgestone World Solar Challenge due to the sponsorship of Bridgestone Corporation is a biennial solar-powered car race which covers 3,021 km (1,877 mi) through the Australian Outback, from Darwin, Northern Territory to Adelaide, South Australia.
The race attracts teams from around the world, most of which are fielded by universities or corporations although some are fielded by high schools. The race has a 28-year history spanning twelve races, with the inaugural event taking place in 1987.
The objective of this competition is to promote research on solar-powered cars. Teams from universities and enterprises participate. In 2013, 40 teams from 23 countries competed in the race.
Efficient balancing of power resources and power consumption is the key to success during the race. At any moment in time the optimal driving speed depends on the weather forecast and the remaining capacity of the batteries. The team members in the escort cars will continuously remotely retrieve data from the solar car about its condition and use these data as input for prior developed computer programs to work out the best driving strategy.
It is equally important to charge the batteries as much as possible in periods of daylight when the car is not racing. To capture as much solar energy as possible, the solar panels are generally directed such that these are perpendicular to the incident sun rays. Sometimes the whole solar array is tilted for this purpose.
- The timed portion of the race stops at the outskirts of Adelaide, 2998 km from Darwin. However, for the timings recorded at that point to count, competitors must reach the official finish line in the centre of the city under solar power alone.
- As the race is over public roads, the cars have to adhere to the normal traffic regulations; however, there is a special note in the official regulations remarking on the tendency of drivers to take advantage of a favourable road camber in order to capture the maximum amount of solar energy. After midday when the sun is in the west, it would be advantageous to drive on the right side of the highway, provided, of course, there is no traffic in opposite direction.
- A minimum of 2 and maximum 4 drivers have to be registered. If the weight of a driver (including clothes) is less than 80 kg (180 lb), ballast will be added to make up the difference.
- Driving time is between 8:00 and 17:00 (from 8 a.m. to 5 p.m.). In order to select a suitable place for the overnight stop (alongside the highway) it is possible to extend the driving period for a maximum of 10 minutes, which extra driving time will be compensated by a starting time delay the next day.
- At various points along the route there are checkpoints where every car has to pause for 30 minutes. Only limited maintenance tasks (no repairs) are allowed during these compulsory stops.
- The capacity of the batteries is limited to a mass for each chemistry (such as Lithium Ion) equivalent to approximately 5 kWh maximum. At the start of the race, the batteries may be fully charged. Batteries may not be replaced during the competition, except in the situation of a breakdown. However, in that case a penalty time will apply.
- Except for the maximum outer dimensions, there are no further restrictions on the design and construction of the car.
- The deceleration of the dual braking system must be at least 3.8 m/s² (149.6 in/s²).
- By 2005, several teams were handicapped by the South Australian speed limit of 110 km/h (68 mph), as well as the difficulties of support crews keeping up with 130 km/h (81 mph) race vehicles. It was generally agreed that the challenge of building a solar vehicle capable of crossing Australia at vehicular speeds had been met and exceeded. A new challenge was set: to build a new generation of solar car, which, with little modification, could be the basis for a practical proposition for sustainable transport.
- Entrants to the 2007 race chose between racing in the Adventure and Challenge classes. Challenge class cars were restricted to 6 square meters of solar collectors (a 25% reduction), driver access and egress were required to be unaided, seating position upright, steering controlled with a steering wheel, and many new safety requirements were added. Competitors also had to adhere to the new 130 km/h (81 mph) speed limit across the Northern Territory portion of the Stuart Highway. The 2007 event again featured a range of supplementary classes, including the Greenfleet class, which features a range of non-solar energy-efficient vehicles exhibiting their fuel efficiency.
- For the 2009 challenge class several new rules were adopted, including the use of profiled tyres. Battery weight limits depend on secondary cell chemistries so that competitors have similar energy storage capabilities. The power difference between gallium arsenide and silicon cells was acknowledged with a separate award for the fastest silicon car in the challenge class.
- In 2013, a new Cruiser Class was introduced. The race took place in four stages. Final placings were based on a combination of time taken (56.6%), number of passengers carried (5.7%), battery energy from the grid between stages (18.9%), and a subjective assessment of practicality (18.9%).
- In the 2015 Cruiser Class regulations, the scoring formula emphasized practicality less than before. Elapsed time will account for 70% of the score, passengers 5%, grid energy use 15%, and practicality 10%.
The idea for the competition originates from Danish-born adventurer Hans Tholstrup. He was the first to circumnavigate the Australian continent in a 16-foot (4.9 m) open boat. At a later stage in his life he became involved in various competitions with fuel saving cars and trucks. Already in the 1980s, he became aware of the necessity to explore sustainable energy as a replacement for the limited available fossil fuel. Sponsored by BP, he designed the world's first solar car, called The Quiet Achiever, and traversed the 4,052 km (2,518 mi) between Sydney, New South Wales and Perth, Western Australia in 20 days. That was the precursor of the World Solar Challenge.
After the 4th race, he sold the rights to the state of South Australia and leadership of the race was assumed by Chris Selwood.
The race was held every three years until 1999 when it was switched to every two years.
The first World Solar Challenge was run in 1987 when the winning entry, GM's Sunraycer won with an average speed of 67 km/h (42 mph). Ford Australia's "Sunchaser" came in second. The "Solar Resource", which came in 7th overall, was first in the Private Entry category.
The 1993 World Solar Challenge
- In 1993 the race was won by the Honda Dream, and Biel School of Engineering and Architecture took second. Video coverage here.
The 1999 World Solar Challenge was finally won by a "home" team, the Australian Aurora team's Aurora 101 took the prize while Queen's University was the runner-up in the closely contested WSC so far. The SunRayce class of American teams was won by Massachusetts Institute of Technology.
In the 2005 World Solar Challenge the top finishers were the same for the third consecutive race as Nuon's Nuna 3 won with a record average speed of 102.75 km/h (63.85 mph), and Aurora was the runner-up.
The 2007 World Solar Challenge saw the Dutch Nuon Solar team scored their fourth successive victory with Nuna 4 in the challenge class averaging 90.07 km/h (55.97 mph) under the new, more restrictive rules, while the Belgian Punch Powertrain Solar Team's Umicar Infinity placed second. The Japanese Ashiya team's Tiga won the adventure class under the old rules with an average speed of 93.53 km/h (58.12 mph).
The 2009 World Solar Challenge was won by the "Tokai Challenger", built by the Tokai University Solar Car Team in Japan with an average speed of 100.54 km/h (62.47 mph). The longtime reigning champion Nuon Solar Team's Nuna 5 finished in second place. The Sunswift IV built by students at the University of New South Wales, Australia was the winner of the silicon-based solar cell class, while Japan's Osaka Sangyo University's OSU Model S won the Adventure class.
In the 2011 World Solar Challenge Tokai University took their second title with an updated "Tokai Challenger" averaging 91.54 km/h (56.88 mph), and finishing just an hour before Nuna 6 of the Delft University of Technology. The race was marred by delays caused by wildfires.
The 2013 World Solar Challenge featured the introduction of the Cruiser Class, which comprised more 'practical' solar cars with 2-4 occupants. The inaugural winner was Solar Team Eindhoven's Stella from Eindhoven University of Technology in the Netherlands with an average speed of 74.52 km/h (46.30 mph), while the second place team was the SunCruiser from Hochschule Bochum in Germany, who inspired the Cruiser Class by racing more practical solar cars in previous WSC races.
In the challenger class, the Dutch team from Delft University of Technology took back the title with Nuna 7 and an average speed of 90.71 km/h (56.36 mph), while defending champions Tokai University finished second after an exciting close race, which saw a 10-30 minute race distance, though they drained the battery in final stint due to bad weather and finished some 3 hours later; an opposite situation of the previous challenge in 2011. The Adventure Class was won by Aurora's Aurora Evolution.
The 2015 World Solar Challenge will be held on October 18-25 with the same classes as the 2013 race.
- Solar car racing
- List of solar cars (with homologation)
- List of solar car teams
- The Quiet Achiever, the world's first solar-powered racecar
Other solar vehicle challenges
- American Solar Challenge, a biennial United States event held since 1990 that has previously included Canada
- Formula Sun Grand Prix, an annual U.S. event held on race tracks.
- The Solar Car Challenge, an annual event for High School students from the U.S. and (to a lesser extent) other parts of the world, first held in 1995
- South African Solar Challenge, a biennial South African event that was first held in 2008
- Victorian Model Solar Vehicle Challenge, an annual event in Australia for schoolchildren
- Race The Sun, a movie loosely based on a participating team
- Wakefield, E.H. History of the Electric Automobile: Hybrid Electric Vehicles. Washington: SAE International.
|Wikimedia Commons has media related to World Solar Challenge.|
- Official website
- Images from Alice Springs, Australia - 2007
- An overview of all the competing teams in the 2013 WSC.