Solar car 'uses less power than toaster'

It's lean, green and can run on less energy than it takes to power the family toaster.

Yet Sunswift IV will reach speeds of up to 120km/h when it races across Australia in the Global Green Challenge race from Darwin to Adelaide starting on October 24.

Students from the University of NSW solar racing team unveiled their hand-built carbon fibre three-wheeler in Sydney's north on Wednesday morning - the only solar car entrant from NSW in the 3000km race.

About 60 team members spent more than 10,000 hours over 18 months designing and building the car, project manager Clara Mazzone told reporters.

"I think the most exciting thing is ... the educational side of it, that none of these engineers have graduated yet, working out how to apply the knowledge they're learning at uni and design and build a car from scratch, basically," Ms Mazzone said.

Last-minute additions were made to the vehicle before the launch to meet RTA requirements.

"All the major mechanical components are in and working, all the absolutely necessary electrical components work. It'll drive," team leader Jono Pye said.

Fondly nicknamed IVy, the car has the same footprint as a small sedan but is half the height and weighs less than 150kg.

IVy is expected to run on 1.3 kilowatts of power from its solar array when travelling at a speed of 90km/h - compared with 1.8 kW needed to run a four-slice toaster, Mr Pye said.

It also has a battery that will run the car for five hours without sunlight.

"Everything is thought (of) to make it as efficient as possible, because the race that it's built for is an endurance race more than anything," Mr Pye said.

The students will take IVy from Sydney to Adelaide before the race and test-run her from Adelaide to Darwin.

They plan to stop at schools on the way to Adelaide from Sydney to showcase their project.

"We're hoping just to get (children) excited about renewable energy, really, and the technologies we're developing, to kind of inspire them to keep it going and show them what's possible," Mr Pye said.

"I think the most amazing thing about it is that a bunch of students have built a car that runs off the sun and can race from Darwin to Adelaide in four or five days," he said.

"And it shows you, if we can do that, imagine what companies and governments can do if they really put their mind to it."

Global Green Challenge for solar and eco-friendly vehicles that attracts competitors from around the world.