A car that runs on just hydrogen and solar power has completed a journey through Australia - the first crossing of a continent for a car of this type.
The car is named Apollondine after Greek gods of sun and water
The organisers say the gruelling 4,000 km trip shows greener alternatives to the traditional internal combustion engine can be developed.
The exhaust emissions of the Japanese-built car consist of pure water.
Sydney's Lord Mayor sampled a glass of it when the experimental vehicle arrived there from Perth.
The car was designed by students at Tamagawa university in Tokyo.
"We could have done it in four days but we didn't want to take any chances; we wanted to show this could be done," said organiser Hans Tholstrup who pioneered solar-powered car races in Australia two decades ago.
The most challenging conditions during the nine-day trip of the vehicle were found in the Blue Mountains to the west of Sydney.
There the region's steep highways coupled with high temperatures made life extremely uncomfortable for the team, says the BBC's Phil Mercer in Sydney.
The car - named Apollondine after the ancient Greek gods of the Sun and the water - travelled a total of 4,084 kilometres (2,533 miles)
"If you're asking when this technology could be commercially viable, then the answer is 'how long is a piece of string?'," Mr Tholstrup added.
"It's interesting that clever university students have come up with this design, instead of the major car companies."
He said sooner or later the major car companies would be using the building blocks his team have pioneered.