World Solar Challenge 2011
For the World Solar Challenge 2011, Endeavour underwent a substantial redesign, replacing the battery pack, canopy, wheel fairings, wheels and driver controls. These modifications resulted in a much more reliable and competitive car for WSC 2011.
The total mass of Endeavour Mark II is 220 kg and it is capable of reaching a top speed of 121 km/h.
The shape of the body was optimised using both computational fluid dynamics and scale wind tunnel models. It is constructed from a nomex and carbon fibre sandwich, which is light but very stiff.
6m2 of the world’s most efficient silicon solar cells produce an average of 1.0kW during the race with a peak output of 1.3kW. For optimum power, the array is split into four separate sub-arrays, each containing about 100 cells.
A 4kW lithium iron phosphate battery provided enough energy to complete 10% of the race. However, its main purpose is to act as an energy buffer, allowing the car to maintain a constant speed despite the change in solar intensity during the course of the day.
Maximum Power Point Trackers (MPPTs)
MPPTs are used to step up the voltage produced by each sub-array of solar panels to our main bus voltage (140V). They also vary the load across each sub-array so as to draw the maximum possible power for the given light conditions.
Motor & Motor Controller
Our motor is a 98% efficient 4kW brushless hub motor, using neodymium-boron-iron magnets. It is operated by a 97% efficient 3-phase inverter. Both have been specifically designed for solar racing, but with other applications.
Our tyres are specifically designed for solar racing and can be inflated up to 80psi for minimum rolling resistance. However, they are still suitable for use across the Outback.
Our spaceframe aluminium chassis is designed simply to be as light as possible and weighs only 15kg.
Within the solar car, electronic devices from the steering wheel to the motor communicate over a CAN bus. A telemetry radio is used to transmit information to our chase car during the race.