Following the announcement of the regulations for the next World Solar Challenge, Mark Nicholson examines what impact this will have on teams hoping to race in 2013.
The World Solar Challenge is a constantly evolving competition, with early teams being allowed to race anything that was considered remotely safe, while modern teams need to meet a stringent set of requirements, many of which are taken directly out of the Road Transport Authorities’ regulations. Today, seating positions and entrance & exit requirements are restricted, and safety in a crash is a key consideration in the rules.
However, the regulations do not only cover safety. The current World Record for the WSC was set by Nuna 3 in 2005, which used over 8m2 of hyper-efficient Gallium Arsenide cells to achieve an average speed of 103 kmph, and which set an incredible top speed of 140 kmph. Since then, the use of these cells has been restricted, first to 6m2 in 2007, and then to 3m2 in 2011, due partly to the incredible cost of the cells, which cost hundreds of thousands, if not millions, of pounds for arrays of the size required for solar racing.
This year, the biggest changes push teams ever closer to the image of a “standard” fossil-fuel-powered car. Teams are now required to have 4 wheels for the Challenge class, and the seating area must meet the National regulations, with a large amount of headspace for the driver, reducing the risk of injury in case of a crash. For comparison, last year every entry that finished the race in the time limit had 3 wheels – so the shift to 4 wheels represents a huge challenge for solar teams. Each of these cars also had a seating position minimising space around the driver, to optimise their aerodynamics – but again, this is no longer allowed, requiring significant modifications to these designs.
Another interesting change is the introduction of a DOT or E requirement on the tyres in the race, which mandates that they must be passed by a road transport authority. Previously, most cars have used “solar” tyres, specifically designed to minimise rolling resistance for vehicles of approximately solar car specification. However, as they are only produced in such limited runs, these do not tend to be road legal in an absolute sense; they are produced solely for solar racing, and so are not properly certified. Whether they will be certified by the time of the WSC itself remains to be seen.
Meanwhile, the team in Cambridge has been brainstorming about the best solutions to the issues raised by the new regulations. Stay tuned for more details!