This month, three UK student teams have flown to Australia to compete in a biennial contest to find the world’s most efficient electric car.
Cambridge University Eco-Racing (CUER) and Durham University Electric Motorsport (DUEM) will compete in the elite Challenger Class of the Bridgestone World Solar Challenge 2015 (BWSC 2015) in the Australian Outback. Meanwhile, the Ardingly Solar Car Team from Ardingly College in West Sussex becomes the first school in Europe to design and build a car for the event and will take part in the Cruiser Class.
From Darwin to Adelaide
The competition, which takes place on 18th-25th October, is in its 28th year and 46 teams from 25 countries will attempt to travel 3,000km from Darwin to Adelaide. The organisers say it is all about ‘energy management’ and explain that based on the original notion that a 1,000W car would do the journey in 50 hours, solar cars are permitted 5kWh of stored energy but the rest must come from the sun or from the kinetic energy of the vehicle. Vehicles can utilise no more than six square metres of solar panels. Teams leave Darwin and must travel as far south as they can by 5pm and then make a camp in the desert. Those in the Challenger Class must complete the race in a single stage. The Cruiser Class, created in 2013 to encourage the design of more practical electric vehicles that carry a passenger as well as a driver, are judged on a range of design and performance measures.
Both the Cambridge and Durham teams have taken part in previous events and their experiences mean they are well aware of what can go wrong. In 2013 Cambridge’s hopes were dashed after a crash during road testing. Although its vehicle, Resolution, was repaired and drivable, it was unable to compete in the main event for technical reasons. Meanwhile in 2011, Durham outperformed many teams in qualifying but once on the road its DUSC vehicle saw its power reduced by half because of cracking in the solar cells. It did continue to run at an average speed of 80km/h and finished 33rd out of 44 entries.
Cambridge has learnt lessons from 2013 and its vehicle Evolution is based on the Resolution concept of prioritising optimal aerodynamics over solar energy intake. Evolution features a cutting edge space grade solar array, which has been rotated by 90 degrees to reduce shading due to the Fresnel losses in the canopy and can orientate itself according to the trajectory of the sun. Durham has built its DUSC2015 from the ground up and it features 392 silicon solar cells, arranged into seven electrical groups. Each group has its own ‘maximum power point tracker’ to ensure there is always correct voltage to charge the batteries. Power comes from a single in-wheel magnet electric motor.
The Ardingly entry is the culmination of three years’ work by around 100 pupils aged 13-18 years and marks the first ever appearance by a European school in the challenge. The vehicle is based on a modified Lotus 7 chassis and features 264 solar cells. It takes a minimum of 26.76 seconds to hit 60mph from the 6,000W (8 horsepower) motors and can reach a top speed of 82km/h. The school has worked closely with CUER on the project.
Preparing for the big challenge
The theory aside though, what is it like to take part in this prestigious global event? Although engineering-led, teams are multi-discipline. During the challenge they could encounter soaring temperatures, fierce cross-winds and other extreme weather conditions, the most challenging of terrains and even bush fires, so how can you best prepare for it?
Aurelia Hibbert, second year engineering student at Newnham College at the University of Cambridge, is programme director of CUER and like all team members has been in Australia for the past few weeks. She took time out from an extremely busy schedule to answer our questions.
What are the biggest challenges now you are out there?
The biggest challenges we face are ensuring that the car is on top form for scrutineering and that the drivers are properly trained and ready to face the challenge. Since our car handles differently from most vehicles it is important that the drivers understand its characteristics before taking it out on the road.
What are your main focuses/activities between now and the race?
Our main activities will be getting out on the roads once the drivers are confident, and practising our race procedures, such as setting the car up for evening charging and tyre changes. We will be spending a lot of time out on the Cox Peninsula road and then at the Hidden Valley Motorsport Complex to get the team running like clockwork when we set off from the start-line.
How is the feeling in the team?
There is a lot of pressure on the team to ensure things go to plan after last time but with true CUER spirit we are maintaining our positivity and drive to show everyone what we are capable of. The team has gelled really well, even with new members joining in Australia, which has helped everyone to maintain their sense of humour even after some very long days of technical work and driving.
What are the most exciting parts of this stage of the project?
The most exciting thing is that we are very close to driving Evolution on public roads for the first time. We have seen a couple of other solar cars out on the road and we are all raring to join them once the car has its permit and the drivers are ready. We are also looking to plan the next stages of the project in more detail, and seeing what may be possible off the back of a good performance in BWSC 2015 is extremely motivating.
Is there anything that has surprised you about the location?
The parts of Australia we have passed through so far have been stunningly beautiful but we have not encountered anything we weren’t expecting. The wildlife has been scarce where we have camped and the trip has gone pretty smoothly.
How would you sum up the importance of teamwork to the project?
On a project like this, where most of the team are volunteers, teamwork is the only way to succeed. We require people that motivate each other and are willing to jump in and help even when they are not entirely confident in the task they are taking on. We teach each other things from our area of expertise in order to increase their abilities and therefore build the knowledge base of the team. If the team did not collaborate effectively then we would not have made it this far.
Many will aspire to be in university team such as this. What would your advice be to those who would one day like to be involved in such a project?
The key thing about everyone in this project is that when they joined they did not understand solar cars. As we have a different design philosophy from many other teams, there are very few places you could go to learn about how we design our cars and run our team. Therefore, people wanting to get involved in similar projects should not be ashamed of starting from nothing and aiming for the top; we have all been there.
You can keep up with developments from all of the teams at a social media hub on the World Solar Challenge’s website at www.worldsolarchallenge.org as well as race progress once it starts.