The World Solar Challenge wrapped up in Australia last week where over 35 teams raced solar vehicles 3000 kilometres from the north in Darwin, through the Australian outback to finish in the south at Adelaide. University of Waterloo’s own Midnight Sun Solar Rayce Car team was there to represent the University to the world.
Team members travelled over 25 hours by Airplane to reach the Northern Australian city of Darwin to meet their Car which had been shipped out in a container back in August. After safely arriving in Darwin, the team was relieved to discover the crate had arrived intact with the car in one piece. Although the team had just arrived, they had mountains of work ahead of them before the race only a few days away.
The vehicle has a custom-built electrical system that connects the solar panels through power electronics to one of the more crucial components – the battery pack. Due to air shipping regulations, the battery pack, a custom built component consisting of many separate lithium cells, had to be disassembled prior to shipping. On the first night, the electrical team pulled an all-nighter to re-assemble the battery pack which took hours and hours of careful work.
The team continued putting together the car to make sure it was fully ready for scrutineering by the WSC officials. Scrutineering ensures each team’s vehicle meets the general and technical regulations of the race. The technical regulations are very specific for both mechanical and electrical systems. For the electrical systems, WSC officials check that each battery is built to regulation and the solar collecting area of the vehicle does not exceed the maximum allowable for the competition. As safety is always paramount, each car must conform to road regulations.
The team was in the first round of scrutineering, for which they were not fully ready. As such, the team had many small items relating to the vehicle that prevented it from being fully cleared to race. After another day’s hard work, the car was re-scrutineered and the car cleared all remaining items on the official’s list.
After being scrutineered, the team spent their 5th day in Australia finally testing their vehicle and getting drivers trained and adapted to the new car. It was close to two months since the team was last able to get the car rolling since it was shipped from their workshop in E5.
In order to determine starting race positions, each team completes a speed trial at the WSC solar testing track called Hidden Valley. This speed trial is crucial to getting a head start on the race, as each team is started spaced apart at the start line to prevent major disruption on public roads caused by 39 chaotic solar cars trying to pass one other. Adding to the challenge, the WSC only has one start time for everyone, thus if a team starts 15 minutes from the main start time, they are already 15 minutes behind in the race.
On the first race day, the Midnight Sun was 17th out of 39 cars to start based on their speed trial lap time completed a day previous which put them 11 minutes behind the lead car at the start. Once the race commenced and the Midnight Sun vehicle was finally on public road for racing, the team was incredibly excited for the dramatic moment after working on the vehicle the past 3 years.
The team pushed the car’s limit a bit on the first day with cruising speeds ranging from 50 to 60kph, but after 2 hours of driving, the vehicle started swerving madly due to a deflated rear tire. After a quick wheel change the vehicle was back on the road, but the problems did not stop there. Around an hour after the wheel change, the solar car stopped and the driver could not get the car moving forward. Air within the brake lines had expanded due to the extreme heat reaching 38 degrees Celsius, which fully closed the brake callipers. The team lost much time fixing this issue but was able to travel 280 km on the first day.
On the second race day, the team had finally reached its first control stop. However, soon after the battery pack, which had been practically built in the days following up to the race, reached a dangerous state for the car to be driven any longer. Desperate and frustrated, the team eventually had to trailer the vehicle to the next control stop. In the meantime, the electrical team had to determine why the battery pack was not able to hold a charge and why the solar array was not effective in charging the battery.
The trailering continued until the control stop of Tenant Creek where a bush fire further up the road stopped the entire race from progressing. Many teams were held back at the stop and the top teams were forced to the side of the road further ahead until the highway reopened. The bush fire incident greatly favoured Midnight Sun as the team took the car off the trailer and started charging during the waiting time, enabling the team to get their battery up to 90% of capacity.
On the 4th day, the team finally arrived at their next control stop of Alice Springs, which marks the halfway point of the race route. Near the end of the 4th day, the team was forced to trailer again as it was not possible to put in another 1500km with two days left in the race.
On 5th day, some teams had already reached Adelaide, but for the rest of the team’s left on the road, the weather was against them. Rain and thunderstorms were not conducive to racing solar cars so many teams began to trailer their vehicle the rest of the distance to Adelaide. At the end of the race, only 7 teams out of the original 39 were able to travel the full 3000 kilometres fully powered by the sun.
The team continued to trailer up until around 100 km before the finish line, allowing the battery to charge and to roll into Adelaide on the car’s own power. As of press time, final times and placement are still being tabulated, but over the course of the race, the Midnight Sun travelled over 1100 kilometres powered by the sun which puts them in a place of 30th overall. A tough drop compared to the last WSC where the team was able to complete the entire 3000 km trek and finished in 9th position overall. However, the number of entrants in the race has more than doubled from 19 to 39 since 2007. The compounding factors of a problematic electrical system along with much-less-than-ideal weather really worked against the team in this race, but the team continues to look forward to being able to prove the competitiveness of the Midnight Sun X at their next solar race event.
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