Sunswift has broken the Guiness World Land-Speed record for a solar-powered vehicle. The record was set at 88km/h by Sunswift IVy on the 7th of January, 2011. The previous record was set by General Motors Sunraycer, which travelled 78km/h on roughly 1500 Watts.

During the day that Sunwift IVy set the record, conditions were mostly cloudy. The record breaking run was at 10:30 AM when we got lucky with enough of a break in the clouds. Solar-noon was at 13:06 that day. The car used about 1050 W to travel at the speed it did for the record run. The batteries were removed, so as to compete on the grounds of energy efficiency alone – i.e. not how big your batteries are.

This means that Sunswift IV, with ~25% less power than the previous record holder, went 13% faster. We’ve come a long way since 1988.

The maximum power we ever saw from the solar array was 1340 W. The clouds never stayed away for long enough to complete any faster runs.

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FAQ

What have you actually achieved?
We have just set the Guiness World Record for a Solar-Powered Land Vehicle.

Is this official?
Yes, it was timed by a professional timing-officer and confirmed in person by a Guinness Oficial
What are the requirements accociated with this record?

The speed is measured as an average speed over 500m in both directions. Both runs have to be within an hour of each other. The course has to meet minium flatness requirements. The vehicle must be powered only by the sun (there were no batteries in the car for the record)

What was the old record?
78 km/h was Set by General Motors Sunraycer in 1988.

What is the new record?
88 km/h was set by Sunswift IVy in 2011

What about [insert other car], didnt they go much faster at [insert event]?
Faster speeds that you see from events such as the World Solar Challenge are achieved with batteries.

Why has this record lasted for so long?
There are many requirements to meet in order to set an official world record. No other team has decided to try to break the official record until now. Hopefully we can get some good competion going with this.

Why is the car the shape it is?
Solar Cars have a very small energy budget. The car has to be extremely aerodynamic and electrically efficient in order to maintain a high speed with such a small amount of power.

Why is is a wing shape, doesnt this generate lift?
An aerofoil is just a fancy name for a tear drop. A tear drop shape is the most efficient aerodynamic shape for minimising drag. Lift is generated when the wing has some angle of attack. The minimum drag orientation is when there is zero lift generated. There is also lift generated due to the ground effect. IVy’s shape is such that there is minimum lift and minimum drag.

Can a person fit inside it?
Yes, a very small person can fit inside it.

What is the point?
Solar Vehicle racing is an exciting sport and an exciting engineering challenge. Team members put the hours into building this car that they do because it is an exciting, challenging and rewarding project. For students, the skills they practice in designing, building, and racing these cars are invaluable in the real world once they leave university.

Electric cars firms will almost certainly be the future of automotive engineering however, and solar technology is going to be an important component of where that electricity comes from, but it will never be used to power a vehicle. Instead what you will likely see is solar power on a roof charging an all electric vehicle running from a battery. Our aim is to develop ultra energy efficient technologies for use in electric vehicles and hybrid vehicles.