A solar-powered aeroplane designed to fly day and night without fuel or emissions has made its first test flight above the Swiss countryside.

The Solar Impulse, which has 12,000 solar cells built into its wings, is a prototype for an aircraft intended to fly around the world without fuel from 2012 to promote renewable energy.

It glided for 90 minutes above western Switzerland at an altitude of 1,000m, with German test pilot Markus Scherdel at the controls.

It took six years to build the carbon fibre aircraft, which has the wingspan of an Airbus A340 and weighs as much as a mid-size car.

Photovoltaic or solar cells supply four electric motors with a maximum output of ten horsepower each. The plane is ultimately expected to attain an average flying speed of 70km/h and reach a maximum altitude of 8,500 metres.