Could algae power cars?

Could tiny green plants called algae power the cars and lorries on our roads?

That's the question Joe's asking in his latest Powering Britain report.

He meets a team of scientists growing algae in test tubes.

Algae feed on the minerals in waste water and turn some of these minerals into oil, which can be converted into biodiesel for engines.

It sounds good, but is it really the answer to our energy needs?