NC State’s SolarPack team has a lot to be proud of. In August, for the first time, they got their solar-powered electric car onto the course of the Formula Sun Grand Prix (FSGP), an annual three-day track competition taking place this year in Topeka, Kansas, and a premier race for U.S. collegiate solar car efforts.
Since 2016, SolarPack has been promoting energy-efficient transportation by designing and developing solar-powered vehicles. The group of about 40 undergraduate and graduate students — and a network of alumni happy to provide advice — places particular emphasis on practicality. They want their cars to be not just efficient and functional but also attractive and usable as a daily driver.
The team’s first vehicle was built from the ground up, and they had it ready to go for 2019’s FSGP in Texas. Unfortunately, they ran into trouble. They managed to repair the issues that cropped up and get the car up and running, but by then it was too late to pass the testing and regulations required to race.
It’s not uncommon for teams to attend an event but not make it onto the actual track, but that doesn’t make it any less disheartening. Despite the setback, SolarPack learned from the experience and got to designing a new custom vehicle. Then COVID-19 hit.
The pandemic and its restrictions affected SolarPack from multiple angles. For one, there were limitations on how many people could get their hands on the vehicle — for a while, they didn’t have access to it or their shop at all. Team meetings were moved online, but certain responsibilities are just hard to accomplish remotely, and as a volunteer club, the virtual transition wasn’t always great for motivation.
The team also became strapped financially. With the uncertainty of the pandemic, funding and sponsorships dried out, which added to the difficulties.
Given the situation they found themselves in, SolarPack decided to chart a different course. They paused their work on their second custom car and took a new approach: renovating an existing vehicle.
“There was an extensive amount of discussion and deliberation,” said Bec Alderson, former SolarPack team lead and current Advanced Energy engineer. “I remember some long meetings with other team leads to try to determine how we could move forward effectively, and it took us some time to brainstorm and figure out a plan. Retrofitting an existing vehicle was certainly a risk in its own way. It had never been done before at FSGP, so we didn’t have any precedent to look at within other teams.”
Still, renovation had a few advantages over building a car from scratch. One was time to develop. A design cycle for a custom car takes about two to three years. Converting an existing one could be completed in under one, and with 2021’s race in the back of their minds, this became an important factor.
SolarPack could have tried to fix and improve their original car, but its chassis bent at the 2019 race in Texas and did not seem salvageable. “It was ruled out once updated simulations showed that it would not be able to take the required impact,” said Charlie Phillips, another former SolarPack member and current quality manager at Advanced Energy.
Herein lies a second advantage of renovation: The team could be confident that the vehicle would be structurally sound, which would allow them to focus on systems that they could not prioritize with their initial car.
But probably the biggest plus was pretty basic: They’d actually have access to the vehicle.
In September 2020, SolarPack purchased a Volkswagen GTI. “We chose this vehicle for a few reasons,” said Alderson. “It is relatively small, with ample space in the rear for batteries; it was for sale for relatively cheap; the only major issue with it was the engine, which we would be removing anyway; and finding replacement performance parts would be relatively easy.”
They then began building. For five months, the GTI lived in the driveway of one of SolarPack’s members as others came by to work on it. They removed the combustion engine and related parts, installed an electric motor, built and mounted the solar array, built a battery containment and mounted the batteries, altered the car’s body and occupant area to meet race regulations, and lots more, pulling in as much as they could from their original car.
After a total of 10.5 months, they were loading the GTI and making the trek west to Kansas. This time they passed all regulations and drove five laps around the track — a huge milestone for the club, especially in light of all of the hurdles they overcame in the past year and a half. During the pre-race scrutineering process, they even scored the second fastest time on the slalom course, which tested for dynamic stability and handling performance.
“With COVID-19 came many difficult engineering obstacles and I can’t be prouder of what we were able to accomplish with project SPX [the name of the GTI conversion] during this period,” said Christopher Ford, current SolarPack project director. “To be able to take SPX to FSGP in July after working on it for under 11 months shows me how goal oriented our team is and how they can adapt to the circumstances that our club faced.”
SolarPack already has its eyes set on next year’s contest and is hoping to challenge for the record for fastest single lap around the track. The team wants to get back to building a custom car, too, but they’ll keep the converted Volkswagen to bring to races. Getting on the track is excellent practice for SolarPack members, and the event gives the group an opportunity to connect with solar car teams from other schools. It’s a healthy mix of competition and collaboration, and a fun reminder of why they do what they do.
“Since the foundation of SolarPack in 2016, the determination, commitment to sustainability, and the desire to learn is what has gotten us to where we are today,” said Ford. “We are dedicated to growing future engineers with the sustainability mindset and engineering design process for the purpose of application wherever their career takes them. I am super proud of how far the club has come and look forward to the future.”