Sunswift unveils next generation solar racing car, takes aim at world solar speed record

Sunswift, the UNSW solar racing car team that in 2018 broke a record for vehicle efficiency driving from Perth to Sydney, is at it again.

After 18 months isolated by Covid-19 lockdowns, the Sunswift team has just unveiled its seventh generation Sunswift, that it hopes will set a new Guinness World Record for the fastest solar electric car over 1,000km.

Weighing in at under 500kg, the solar-powered car is the work of 50 UNSW undergraduate students and 25 years’ worth of R&D know-how.

To achieve the desired weight, the team has added none of the mod cons usually seen in a passenger car. Sunswift 7 does not have air conditioning, ABS brakes, airbags or even windscreen wipers.

To further improve efficiency, the design team led by Ben Heina has refined the sleek Sunswift shape to the point it has an incredibly low drag coefficient of 0.095.

To put that in perspective, the Tesla Model S has a drag coefficient of 2.08, and the Lightyear One solar car – which is due to premiere in Europe overnight – comes in at 2.0.

“I went through 57 iterations of design before the final shape was determined, and in between that we had to make sure that everything else was going to work,” he said.

“So, how are we actually going to fit the solar cells on the car? How curved do they need to be? Can the solar cells withstand that curvature? Is there room for the suspension? Is there enough space for a driver?”

Richard Hopkins, team principal and former Red Bull Racing Formula One operations head, says the team has worked incredibly hard during what has been an equally difficult time to achieve these desired measurements.

“They were given the freedom to create. The criteria was simply: build a car that has solar power and a battery. I had very little influence over what they chose to do within that – I just wanted them to make the best engineering decisions,” he said.

“In that high-pressure environment, when you are losing you can feel as if you are at rock bottom, but you know you have to retain your focus and work exactly the same as if you were winning.”

“You draw on a resilience you never knew you had. I think in that situation, it was just important for the Sunswift team to continue to communicate,” he said.

The record attempt will take place at the Australian Automotive Research Centre in Victoria. To break the record, the 1,000km must be driven on just one single charge of its solar-powered battery at an average speed of 120km/hr.

But the team says that it can already travel more than 1,200km on a single charge, and can reach a top speed of 140km/hr.

Key to its efficiency is also its bearings, which are top-notch to ensure as little rolling resistance as possible.

Says Hopkins: “We are using a standard battery and a standard solar panel, but we have focused on making it a super-efficient car and shown what is possible.

“That efficiency means once we get up to 100km/h and take the foot off the accelerator I don’t think there is a straight stretch of road long enough, except for maybe somewhere in the Nullarbor, to measure how far it would keep going all on its own.”

While it may be some time before a production car with these types of specifications is commercially viable, Sunswift team manager Andrew Holden says the short-term end game of breaking the record for fastest solar car is in sight.

“Personally, I don’t think there is anything to say that in 20 years, even 10 years, we couldn’t have a regular production electric car that weighs 500kg with full safety features included that can travel 1000km on a single charge,” she said.

“With the Guinness World Record, if we can prove that we can drive a car at reasonably high speed and do 1000km, it proves the technology exists. We just need to do some polishing with that technology to make it mainstream.”

Hopkins says the final design the team has achieved is “insane.”

“Sunswift 7 is the manifestation of their collective minds, who on day one probably had very little idea what they were doing. And now to produce this amazing car is just insane,” says Hopkins.

“Let’s remember, these are not the best paid professional car makers in Stuttgart working for Mercedes. This is a bunch of very smart amateurs who have taken all the ingredients and put it together in a brilliant way.”