The University of KwaZulu-Natal (UKZN) School of Engineering has unveiled the solar-powered car that will be the first African entrant into the biennial Bridgestone World Solar Challenge to be held from October 18 to 25.
Named Hulamin after the aluminium manu- facturer that funded the project, the solar car is an undergraduate engineering final-year project led by Kirsty Veale and Clinton Bemont. The team includes students and staff from the mechanical, electronic and computer engineering faculties.
Bemont explains that the car will travel just over 3 000 km across the Australian outback on public roads stretching from Darwin to Adelaide.
The UKZN solar car team is one of 47 teams from 25 countries. Many teams have been participating in the race since its inception in 1987. The South African car has been entered in the Challenger class, which is the premier segment of the event and by far the most competitive. Despite the fact that the Hulamin project cost just a tenth of that of many of its competitors, Bemont says the team is confident that it will perform well.
The car will be shipped to Australia on July 31. Once there, a special nonreflective coating that is hypersensitive to touch will be applied just before the race begins.
The aerodynamically designed car is 5 m long, weighs around 230 kg and has a very low drag coefficient of just 0.07, which enables it to go both faster and further. It is lightweight, yet rigid and safe, with a monocoque chassis that comprises 3 mm polyvinylchloride foam and a skin of 0.2 mm carbon composite.
The asymmetrical design features a highly aerodynamic profile with a very small frontal area.
It is powered by US-manufactured super-high- efficiency silicon solar panels, covering an area of 6 m2. Bemont says the energy will be stored in lithium-ion batteries weighing 21 kg.
Although the car can run on 2 kW of energy – roughly the same as that used by a toaster – it is capable of output of up to 5 kW sourced from the battery pack for challenging areas such as hills.
He adds that the Hulamin car boasts a number of innovative design features, including an innovative suspension with a front swing arm and custom cruise control. The car is fitted with many sensors that collect data from a variety of different sites and record everything from the tempera- ture of the photovoltaic panels to the output of the car. This is fed back to a central computer in a following vehicle, which calculates the optimal speed needed and sends this back to the vehicle so that it can optimise its efficiency.
Bemont says the team is able to “sun” its car between sunrise and the 08:00 start of the race to build up energy. Because race rules stipulate that no one can support the car, the team has created a 2 kg mechanism that will tilt the car to achieve the best exposure to the sun.
Work on creating a solar car at UKZN began in 2012. The car that will go to Australia is the second car that has been built from scratch.
“We’ve built on and enhanced the 2014 car and kept part of the original team. That places us in a strong position to compete,” says Veale.
The initial car, named iKlwa, won the national 2014 Sasol Solar Challenge and set distance records in the Olimpia class.