Venice's vaporetti to run on purified cooking oil as part of 7-month experiment The Italian city is trying to make its transport greener.

LONDON -- Vaporetti, Venice's public water buses, will be powered with biodiesel fuel for the next seven months, an experiment by the Italian city to become more green.

The public transport company Gruppo AVM, the waste disposal company Veritas and the Italian oil and gas multinational Eni, are also behind the project to convert cooking oil into biodiesel to power the public water buses.

As part of the experiment, Veritas will collect and purify used cooking oil from various sources such as restaurants and deliver it to a biodiesel refinery run by Eni, which will then purify and convert the oil into fuel.

The trial started April 1 and ends in October.

Venice's experiment is not the first time cooking oil in the form of biodiesel has been used for fuel.

Some drivers of London’s iconic black cabs are regular clients of Uptown Oil – a biodiesel start-up that collects used cooking oil from restaurants and fast-food chains to convert into fuel.

The cabbies – as the drivers are known – pay around 35 to 70 cents per liter for the fuel, compared to commercial diesel that's twice the price. The black cabs are expensive vehicles, costly to maintain and replace, and the biodiesel scheme has been a boon to many drivers who cover their own expenses.

The plan has also been welcomed in a city that struggles to dispose of excess oil and fat, an operation that costs the private company Thames Water – which runs a monopoly in London - $16 million a year in the removal of blockages alone.