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The Philosophy behind the Development of the Classes

By Chris Selwood, Event Director

Primarily a design competition to find the world’s most efficient electric car the biennial World Solar Challenge seeks to inspire some of the brightest young people on the planet address the imperatives of sustainable transport. 

The original and largest event of its type, it maintains its position by offering an adventure of epic proportions; Crossing a continent in a single stage using only sunlight as fuel.

Every two years, teams from around the globe work tirelessly to design and build an ultra-efficient electric vehicle, bring it to Australia and, in the spirit of friendly competition, prove their concepts in one of the world's harshest environments; the central Australian desert.   

The philosophy of evolving design parameters and creating regulations around what must be achieved, without dictating how they are to be achieved, not only encourages creativity and lateral thinking, but provides a unique opportunity of engaging with some of the issues which face us all and a philosophy which has led this famous international event to its position of global dominance.

This openness has fostered the innovative strength of thought that continues to come to the fore as teams look to create the ultimate efficiencies in energy capture, storage and conversion. The World Solar Challenge may have the sun as its nucleus but its innovation reaches into many other areas such as advanced composite materials, low rolling-resistance tyres and innovative power-electronics capable of ultrafast switching of the high current inductive loads demanded by modern EV powertrains.

When first devised, the solutions were only limited by the imagination, although practical considerations were soon to drive the regulations.  If solar cars were to drive on public roads, they should be of an appropriate size.  If the cars were truly solar powered, there should (for the purposes of a competition) be a limit on the stored energy they brought with them. 

So, based on the admittedly somewhat fanciful notion that we, as humans, each have 8 square metres of the earth’s surface from which to draw our sustenance, solar collectors (not defined by type) were originally limited to 8 square metres, however with more efficient conversion leading to faster cars, this was dropped to 6 square metres in 2009 and, in 2011, space grade technologies such as Gallium Arsnide were limited to 3 square metres.

Energy storage limits, again for the sole purpose of competition, “retained to this day” a relationship to the power required to complete the course and, as far as we are aware, the World Solar Challenge is the only event which does this.  Based on a reference point that if a 1 Kilowatt car could complete the course in 50 hours, we consider it reasonable to allow 10% of the energy requirement to be stored to assist with hills, clouds, or extra acceleration for overtaking.  Thus a nominal figure of 5Kw/h was, and remains, the original determinant of the allowable mass of batteries, and the basis of the current calculation by class.

Rapid advancements in technology coupled with a growing acceptance of the imperatives of environmental action require constant review and evolution of the design parameters required to keep the Challenge both attractive and relevant.  Experienced teams need to be pushed in order for innovation to flourish, but at the same time the tasks should not be seen as impossible by newcomers.

Motivators also change with time.  At one end of the scale we have young people inspired to attend by what they read and saw as children, and seek the adventure. At the other, the brightest students take a 2 year sabbatical to immerse themselves in the project thus gaining wide ranging experience beyond campus life.

The world is also changing.  In early events there were few reference points for home made vehicles or regulations for electric cars.  This led to to the development of road protocols and safety regimes specific to the event. That these were adopted by other events proved their efficacy.

Now the developed world recognises myriad regulations for ‘individually constructed vehicles’ harmonized by the UNECE. The Institute of Electrical Engineers has set wiring standards of electric vehicles, and transport authorities around the world are reacting to the rapid developments in urban mobility and the technology which drives it. 

The World Solar Challenge.  Adventure. Innovation. Achievement.