The company’s bus manufacturing wing, Volgren, is trialling several different types of alternative fuels in anticipation that the world’s diesel reserves may run low in the next 25 years.

Volgren director Scott Grenda said it was using three buses valued at a total of $10 million in Perth.

“We have been trialling it for two years now,” he said.

“But it’s not commercially viable in the world at this point.”

Mr Grenda said the hydrogen-powered buses ran well but were tricky to refuel – if any dirt or oil entered the hydrogen it could create difficulties.

He said Adelaide was home to several biodiesel buses that used a combination of diesel with a significant percentage of additive, such as canola oil, to reduce diesel consumption.

“The trials have been driven by emissions,” he said.

“Buses nowadays are clean but there is still that perception of pollution with black smoke buses.

“What we are doing is seeing how these new vehicles work in the commercial world.”