Sir Richard Branson's new cruise line to sail under name Virgin Voyages

Virgin founder Sir Richard Branson

Sir Richard Branson has revealed new details on his latest pet project that will expand his travel empire into the world of cruising.

After commercial space travel, hotels, private islands, airlines and trains, Branson has announced that his newest venture, cruises, will be launched under the banner of Virgin Voyages.

By 2020, the first of three cruise ships will drop anchor in Miami -- Virgin Voyages' home port -- where it will set off on Caribbean itineraries. The vessel will host more than 2,700 sailors and 1,150 crew members.

Ships are being built by Italian shipbuilder Fincantieri.

Branson also announced that the cruise line has partnered with clean energy company Climeon to power their seafaring voyages.

The Climeon Ocean system claims to transform low-grade energy into clean electricity that's estimated to save 5,400 tons of carbon dioxide annually per ship -- an amount that would otherwise take 180,000 trees 30 years to absorb.

The preoccupation with green cruising grabbed headlines this year when the Crystal Serenity became the world's first luxury cruise liner to sail through the fabled Northwest Passage this summer -- a feat made possible by the effects of global warming.

Though shipbuilders made efforts to reduce its carbon footprint with low-sulfur Marine Gas oil fuel, critics lambasted the voyage for what they call a decadent invasion on one of the last pristine frontiers on earth.