NWU students’ solar car takes on the world’s best

Christi Cloete -- Mon, 08/24/2015 - 15:35

NWU students’ solar car takes on the world’s best

Engineering students at the North-West University (NWU) are taking a big bull by the horns and in October this year they will rub shoulders with the big names in solar energy when they take part in the Bridgestone World Solar Challenge in Australia.

Following the NWU’s successes with their participation in the local Sasol Solar challenges in 2012 and 2014, the team decided to build a better and faster vehicle propelled by solar energy. The first competition in which the NWU competed, covered more than 5 000 km and this team and that of the Tokai University in Japan shared the laurels.

According to prof Albert Helberg, team leader, they have now harnessed new technology to make the new vehicle faster, lighter, more effective and stronger. This vehicle is propelled by the amount of energy used by a hair drier. The competition takes place from 18 to 26 October and starts in Darwin in the north of Australia from where 45 vehicles from 25 countries will be racing more than 3 000 km across the country to Adelaide. “We should cover the distance in seven days but we are aiming to do it in five days,” says Helberg.

The NWU team is one of only two teams in South Africa and Africa that will be competing in this so-called Dakar of solar rallies. Thus named due to the harsh circumstances and searing heat conditions of the Australian outback that forms part of the route. “We will be competing against the top universities in the solar energy fields and want to prove that we can align ourselves with their expertise. We can indeed compete with them and we want to prove this to the world.”

There are three classes in the competition. This year the NWU team will participate in the Challenger class, which is without a doubt the most challenging one. According to Helberg it’s all about the vehicle’s speed and efficiency. He says that traditionally only one third of all participants complete this distance in the allotted time.

Team members
The NWU team consist of students, lecturers, a media section and a former student of whom only a few will be fortunate enough to be part of the race in Australia. Two undergraduates will be in charge of the electrical and the mechanical aspects respectively. Two master’s students will be responsible for the advanced electrical systems and will also drive the vehicle. Two lecturers and a former student will take the lead with technical issues. A media section will accompany the team to ensure the world stays abreast of their progress.

Technology
When comparing the NWU’s first solar car with the new one, the biggest difference is the weight. The Batmobile, as the first vehicle was christened in 2012, weighed more than 300 kg. The new Sirius X25 – named after the closest star to the earth’s solar system and which shines 25 times brighter than the sun – is bigger than its predecessor and weighs a mere 185 kg.

The drive system changed from two front-wheel drive motors in 2012 to a single rear-wheel drive motor. The battery pack is technologically better and also weighs less. According to Helberg this is a very innovative battery pack that allows the configuration to be adjusted.

The aerodynamics of the cockpit profile was improved by means of the latest sailplane technology in the world. The sailplane manufacturer, Jonker Sailplanes, did astonishing work here. The vehicle’s control systems have brand-new technology that makes it possible to perform adjustments to the vehicle’s electric current during changing weather conditions, uphills and downhills and while it is operational. It allows the driver to steer the vehicle as effectively as possible. An optimisation system is used in the tracking vehicle, which will determine which adjustments have to made to enhance the effectiveness of the solar car even more.

Solar panels of six square metres are affixed to the top of the vehicle and these are more than half as effective as traditional solar panels affixed to the roofs of houses. The cockpit profile is manufactured with carbon fibre and resin. This makes the vehicle very light but also strong as safety is the first priority. The combination of carbon fibre and resin is three times stronger than steel, but obviously much lighter.

Performance
According to Helberg the objective of this year’s vehicle is to be at least 25% better than its predecessor. “We are still in the building process but it seems as if we will achieve the near impossible. The vehicle must be able to travel at least 500 km per day to be able to finish the race within the time limit. The speed of the Sirius X25 is limited to 120 km per hour but according to our research the most effective speed is approximately 75 km per hour,” says Helberg.

Teams will stop next to the road at night where they will be able to pitch their tents and cook so that they can be off on the next lap the following morning. A racing official and a medical first-aid person will accompany every team during the race.

Objective
“Our biggest dream will come true if we can only finish the race and at the same time be the first team ever from Africa to cross the finishing line. This will put us in the record books. This project is a learning project, which forms part of our long-term vision. This experience will enable us to aim for a podium position in 2017. It can be done. We have the expertise to develop our own technology further and better,” says Helberg.

Helberg explains the team’s holistic approach to their participation in this race. “This race is not merely another race that will cost millions of rand for finishing-line glory but has an incredible influence on the ordinary man in the street. It all happens in the name of the development of better and more effective power systems. Approximately 50% of all electricity in South Africa is consumed by electrical appliances such as electric motors, washing machines, water pumps and drive systems in factories. If one can only replace all traditional household electrical appliances with appliances that work a mere 5% more effectively, the energy saving is equal to over half the electricity that the Koeberg power station generates.

“In building this vehicle, we are proving that all personal energy needs can be met by renewable energy, even your transport needs. We are proving that it is possible but because these contemporary components are not yet produced on a mass scale, not everyone can afford them. This is an effort to turn this around. This technology creates the vision of independence – not to be linked to a grid any longer. It is environmentally-friendly energy, free and at no cost!”