A solar-powered plane that will be taken on a round-the-world journey in 2015 is set to make its inaugural flight on Monday.

The Solar Impulse 2 will take off from Payerne airfield in Switzerland.

It is a larger, upgraded version of the aircraft that flew across America last year with adventurers Bertrand Piccard and Andre Borschberg at the controls.

The two men want to push the boundaries for alternative energy and believe their plane can be a standard bearer.

The SI2 has completed a series of ground and taxi tests in recent weeks that saw it almost reach take-off speed on the runway.

Project leaders are now confident all systems are ready to go airborne, and the Swiss Federal Office of Civil Aviation is satisfied the vehicle is airworthy.

Assuming the weather is compliant, the plane should take to the skies above Switzerland at about 07:30 Central European Summer Time (05:30 GMT; 06:30 BST).

(BBC)