When some students at North Carolina State University decided to to enter the American Solar Challenge — a biennial race for solar powered cars — they knew they would be up against some fierce competition from students at other colleges and universities. Typically, the cars that enter are little more than go karts with a few solar panels held in place with cable ties. But Byron Sells, who began the solar car challenge at NCSU, wanted more than just a car that would just limp across the finish line as the wheels fell off. “I told the team, ‘Let’s make something compelling that the consumer actually wants to buy,’” he says.
Sells is majoring in mechanical engineering and has had a longstanding interest in automobiles and alternative power sources. In 2016 he interned at EVX Ventures, a company in Australia that focuses on solar vehicles and related technology. Once back in North Carolina, he decided to put his internship experience into practice at NC State.
He formed a new campus organization called SolarPack and recruited fellow engineering students to join the team. Later this month, the completed car will compete in the Formula Sun Grand Prix, a performance event held on a closed race course that tests the cars entered for handling, braking, and acceleration. On the years when the American Solar Challenge is held, the FSGP acts as a qualifying series for the ASC. This year, it will be held in Hastings, Nebraska. Later this year, the teams that qualify will leave Hastings to journey 1,700 miles to Oregon, stopping at several checkpoints along the way.
The amount of sunlight that falls on a typical car isn’t enough to power it, says engineer Ewan Pritchard, associate director for the Advanced Transportation Energy Center and the team’s mentor. SolarPack needed a unique design with space to put solar panels, room for batteries, and an aerodynamic shape that would allow the vehicle to use as little energy as possible while driving.
“We spent a lot of time scratching our heads and being confused because there was no pre-existing platform for us to build on, no foundation,” Spells says. “Historically, a mechanical engineer with maybe a little bit of electrical experience could be the only person designing the car,” Spells says. “It’s not that way anymore.” So SolarPack got busy attracting people with other talents. “Engineers aren’t always the best at raising money or speaking to people,” he says. “Business students are more trained for that.” SolarPack now has more than 40 undergraduate and graduate students involved with the project. In addition to the college of engineering, some are from the industrial design center and others from the Poole College of Management.
The car isn’t quite finished yet, so there are no photos to show. But it will be nearly 16 feet long and 5 feet tall — about the size of Toyota Corolla. Inside will be room for 5 passengers. The roof will be covered with solar panels, from the windshield header to the rear of the car. To get more space for solar panels, there will be no rear window. There is a rear view camera instead. Not surprisingly, there is no radio, no heat, and no air conditioning as of yet. “We have a lot of things to consider in the first design to get the car up and running, and we don’t want to sacrifice our time with things like that,” Spells says. “In future vehicles, perhaps.”
Power for the solar car will come from 500 lithium titanate oxide cells which are split into two battery modules — one at the front and the other at the rear. The cells have the right balance between energy efficiency and power, Ewan Pritchard says, and unlike conventional lithium ion battery cells, they are not prone to catching fire. Range with a full battery will be around 250 miles — more than enough for people to go about their daily driving chores while letting the batteries recharge from sunlight when not being driven. 0 to 60 in 6 seconds and a top speed of 98 miles per hour are projected for the car.
Weighing about 2,000 pounds, the NCSU entry will be heavier than other entries, which will be a handicap in the competition. “Our goal is not to win the competition,” Pritchard says. “Our goal is to learn as much as we can through entering these competitions while figuring out how to incorporate solar into a more conventional vehicle to make it more practical. We know it’s a long way away from us creating a fully solar-powered vehicle, but how much solar can we get? And what are the best ways to manage it?”
“It speaks to the team’s notion of not building a go-kart but building a real consumer-acceptable vehicle,” Pritchard adds. “I do have confidence that their design will fundamentally change the dynamics of the American Solar Challenge, and the rules will be different moving forward, probably as they see this vehicle and go, ‘Wow, this is what we should really have been pushing these teams to make.’” The motor is the most powerful the American Solar Challenge has seen to date and the batteries were completely new to competition officials.
SolarPack is doing outstanding work. Their car is similar to the Sono solar powered car developed by a team of young German entrepreneurs and looks remarkably similar to the Sondors electric car that may or may not ever make it into production. If you want to support the SolarPack effort, which has raised about $65,000 so far, you can contact Support at SolarPack directly. Any contribution to this challenging and exciting project would be most welcome. If the team succeeds at the American Solar Challenge, it may participate in the next running of the World Solar Challenge in Australia.