A plane powered entirely by the sun has set off from Seville on the last leg of its journey around the world.

The Solar Impulse 2 is making its way to Cairo on a trip expected to take 50 hours and 30 minutes.

The aircraft is set to make history if this trip is completed as it is the first plane to make such a long journey with zero emissions and no fuel.

The plane has just two more flights to complete after which, it will arrive in Abu Dhabi in the United Arab Emirates where the trip around the world began in March 2015.

The wings of the aircraft are wider than those of a Boeing 747 and hold 17,000 solar cells that power propellers and charge batteries. The plane stores energy during the day to run on at night.

It is a single seated aircraft, piloted in turns by two Swiss aviators, Andre Borschberg and Bertrand Piccard.

Swiss adventurers Bertrand Piccard and co-pilot Andre Borschberg. Picture by: WINFRIED ROTHERMEL / AP/Press Association Images

There are 10 cameras on board the plane so you can track its progress online.

The company behind Solar Impulse 2 hope that this journey will bring attention to the fact that steps toward clean energy can be made. 

"Public attention must be drawn towards the changes necessary to ensure our planet’s energy and ecological future."

"A positive and stimulating image of environmental protection must demonstrate that the alternative energy sources, related to new technologies, can achieve what some consider impossible."