SOLAR-POWERED: Meet the new Sirius X25 – named after the closest star to the earth’s solar system and which shines 25 times brighter than the sun – its bigger than its predecessor and weighs a mere 185kg. Image: Supplied
CAPE TOWN - Engineering students at the North-West University (NWU) will take on rivals at the 2015 World Solar Challenge in Australia in October.
Following the NWU’s successes in the SA 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 5000km. NWU and team and that of the Tokai University in Japan shared the laurels.
According to professor 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 October 18 to 26 and starts in Darwin in the north of Australia from where 45 vehicles from 25 countries will be racing more than 3000km across the country to Adelaide.
Helberg said: “We should cover the distance in seven days but we are aiming to do it in five days.”
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. Teams will take on the searing heat of the Australian outback.
Helberg said: “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. In 2015, 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.
Compared to 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 300kg.
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 larger than its predecessor and weighs a mere 185kg.
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 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.
According to Helberg the objective of this year’s vehicle is to be at least 25% better than its predecessor.
Hellberg said: “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 500km per day to be able to finish the race within the time limit. The speed of the Sirius X25 is limited to 120km/h but according to our research the most effective speed is approximately 75km/h.”
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.
Helberg said: “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.”