Automotive

Four-seat electric sedan on its way to compete in 3,000-km solar race

Four-seat electric sedan on it...
The Sunswift Violet four-seat electric sedan has been designed and built by undergraduate student members of the Sunswift solar racing team at the University of New South Wales
The Sunswift Violet four-seat electric sedan has been designed and built by undergraduate student members of the Sunswift solar racing team at the University of New South Wales
View 8 Images
The Sunswift Violet four-seat electric sedan has been designed and built by undergraduate student members of the Sunswift solar racing team at the University of New South Wales
1/8
The Sunswift Violet four-seat electric sedan has been designed and built by undergraduate student members of the Sunswift solar racing team at the University of New South Wales
Aero designs getthe Violet's drag coefficient under 0.2
2/8
Aero designs getthe Violet's drag coefficient under 0.2
Upper surfaces of the Sunswift Violet electric sedan are covered in 284 microcrystalline solar cells
3/8
Upper surfaces of the Sunswift Violet electric sedan are covered in 284 microcrystalline solar cells
Render of the Sunswift Violet's cockpit
4/8
Render of the Sunswift Violet's cockpit
The Sunswift Violet electric sedan undergoing pre-race testing at the Sydney Motorsport speedway track in Eastern Creek, New South Wales, Australia
5/8
The Sunswift Violet electric sedan undergoing pre-race testing at the Sydney Motorsport speedway track in Eastern Creek, New South Wales, Australia
The Sunswift Violet electric sedan undergoing pre-race testing at the Sydney Motorsport speedway track in Eastern Creek, New South Wales, Australia
6/8
The Sunswift Violet electric sedan undergoing pre-race testing at the Sydney Motorsport speedway track in Eastern Creek, New South Wales, Australia
Upper surfaces of the Sunswift Violet electric sedan are covered in 284 microcrystalline solar cells
7/8
Upper surfaces of the Sunswift Violet electric sedan are covered in 284 microcrystalline solar cells
The Sunswift Violet four-seat sedan has two 1.5 kW electric motors, Li-ion batteries and runs on Bridgestone tires
8/8
The Sunswift Violet four-seat sedan has two 1.5 kW electric motors, Li-ion batteries and runs on Bridgestone tires
View gallery - 8 images

The Sunswift Violet set off on a meet-and-greet tour earlier this week, ahead of the Bridgestone World Solar Challenge next month. The four-seat electric sedan rocks 284 microcrystalline solar cells on the upper surfaces of the vehicle, giving a peak output of 1.1 kW, and has been designed for "practicality, speed and endurance." Such aspects will be tested to their limits during the 3,021-km (1,877-mi) race from Darwin to Adelaide.

The 6th-generation vehicle, with previous creations having secured world speed records for an electric vehicle in 2011 and 2014, has been designed and built by undergraduate student members of the Sunswift solar racing team at the University of New South Wales (UNSW), which was founded back in 1995. It's due to battle it out for the top spot against 47 teams from 21 nations in this year's Bridgestone World Solar Challenge, which starts on October 8.

"Violet looks like a family sedan, but uses as much power as a four-slice toaster," said team leader Simba Kuestler. "She's got entertainment and air conditioning systems, including navigation, reverse camera parking sensors, and there's even Wi-Fi aboard. And she's got plenty of front and rear boot space."

The Challenge takes the form of a race from Darwin to Adelaide, notching up some 3,021 km along the way. But before the Sunswift team even crosses the start line, the Violet car is being taken on a 4,300-km (2,672-mi) road trip, meeting with communities along the way – including stops at Coober Pedy and Alice Springs – to promote the Challenge and the tech.

The Sunswift Violet electric sedan undergoing pre-race testing at the Sydney Motorsport speedway track in Eastern Creek, New South Wales, Australia
The Sunswift Violet electric sedan undergoing pre-race testing at the Sydney Motorsport speedway track in Eastern Creek, New South Wales, Australia

The car is reported to be capable of reaching a top speed of 130 km/h (80 mph), though the team will need to keep under 60 km/h to drive along on solar power alone. Maximum PV-only range is said to be 800 km (just under 500 mi), but Li-ion batteries, which are topped up by the sun, also offer a battery-only range of 400 km. The Sunswift Violet has two 1.5 kW motors that are reported to run at 98 percent efficiency, rolling 9 horses (7 kW) at 110 km/h and delivering 90 Nm (66 lb.ft) of torque.

The carbon-fiber monocoque chassis and aluminum front and rear suspension help the sporty sedan keep its weight down to 380 kg (838 lb), and aero designs get drag coefficient under 0.2. The video below shows the Sunswift Violet undergoing pre-race testing at the Sydney Motorsport speedway track in Eastern Creek, New South Wales, Australia.

Source: Sunswift

UNSW Sunswift Violet: TV B-roll (September 2017)

View gallery - 8 images
9 comments
Bob Flint
Well done, actually looks the most realistic vehicle ever for the sun challengers, in many years.
Keep up the great work!
Joshua Tulberg
very cool. Glad to see they are not seating 4 ppl and have doors/windows.
eMacPaul
I must be missing something. How do two 1.5 kW motors put out 7 kW of power?
Leonard Foster Jr
6th Gen still nothing for the public :-(
BeinThayer
Cruising at almost 40 mph with less than 1.5 hp (solar only) is pretty i pressive for something with 4 seats and 4 doors.
Daishi
@Leonard Foster Jr It's good science but I'm not expecting solar panels to make sense on cars for a looong time. You can get at most about 2 kW of panels on a car. The average Tesla driver sees about 320 watts/mile efficiency meaning 1 hour of solar power is worth about 6 miles of distance. With ~6 sun hours per day you are looking at about 35 miles of range for a day of charging on panels. The grid cost of that electricity is about $1.44 (12 cents/kW). With that range comes added manufacturing costs, complexity, repair costs, insurance costs, first responser safety considerations etc. You also have a great deal of the suitable vehicle surface area that must be used for glass for human visibility.
I expect improvement but what would be required to make it work is closer to a breakthrough and for as long as the vehicle must accommodate human passengers and their safety I don't expect to see one. Solar powered autonomous vehicles on the other hand may become viable because it could just be a flat skateboard platform with panels on top and wheels on the bottom. I think that's the more likely application of this technology.
MirekKaras
Not bad, however I will approach the problem differently. How about convert any electric car into solar car. How? Well why not add light 2 weels flat bet with solar panels? Such flat bet will have minimal air drag.
YuraG
@Daishi - Does a Tesla (even if model 3) weights and correspondingly consumes the same amount of juice as the Sunswift Violet (yes, their aerodynamic numbers are pretty close)? Doesn't the former have a huge and very heavy battery and is meant to compete with gas-powered cars on looks and ride quality? Doesn't this car compete with bicycles, yoga, and rabid tree-hugging:)? What's the price of sun power when you have no grid nearby? What complexity in this thing are you talking about (a couple of hundred well-laminated cells sitting on top aren't there to be replaced every month, they are basically a paint that generates power)? What added manufacturing costs you mean if this thing has a tiny battery (so you have less expensive stuff to assemble while the solar cells are cheap and simple to solder and glue to the body)? What extra human visibility you need in this car (or in less-visible-through Stella Vie)? Isn't you reasoning affected by your investment in a Tesla/Tesla? The Sunswift Violet also tries to look similar to a car we have used to, but is sacrifices its aerodynamics and the cells positioning/area. Stella Vie is the same idea as the Sunswift Violet, but better conceived and executed. But I wish them (including Tesla) tons of luck!
David Priol
Go guys and gals and whip some international butt!!!