An electric-powered van launched a trip Thursday to cross eastern and southern Africa, in an expedition designed to showcase the endurance of the vehicles and promote green energy use.

"We want to break the cliches of electric-powered vehicles," said driver Xavier Chevrin, speaking at the expedition launch in the Kenyan capital, at the offices of the UN Environment Programme (UNEP), which is backing the trip.

The vehicle will set off Friday on an estimated 5,000 kilometre (3,000 miles) journey, heading south through Tanzania, Zambia, Zimbabwe and Botswana, before finishing in the South African city of Johannesburg in late June.

UNEP said it was the "first time ever an electric car has been the vehicle of choice" for such a trip.

Chevrin said the six-nation trip would show that electric cars could travel long distances, and were not only for use in the city. It will recharge its batteries at electric sockets along the way.

"It is being deliberately exposed to these difficult conditions in order to prove the reliability, robustness and endurance" of the car, a statement from the expedition read.

The souped-up Citroen Berlingo van -- powered by an electric motor made by Venturi -- is the same as those used by La Poste, the French postal service.

With three batteries, two more than usual, it can drive for up to 500 kilometres (300 miles) on a single charge and hit speeds of 110 kilometres (68 miles) per hour.

The trip is the latest of several challenges set up to show the capabilities of electric vehicles.

It follows a 2010 journey by Chevrin, who drove 13,400 kilometres (8,300 miles) from Shanghai to Paris in a similar van, the longest journey ever made in an electric vehicle.

In 2009, an electric car registered a top speed of 515 kilometres (320 miles) per hour racing across salt flats in the US state of Utah.

Another expedition is being planned to drive an electric-powered vehicle from the edge of Antarctica through the snowy wilderness to the South Pole.