Solar energy

Silicon solar cells at the photovoltaic solar power plant on the appropriately named Mont Soleil in the Bernese Jura mountains (Keystone/Gaetan Bally) Keystone
The Paul Scherrer Institute's solar oven can concentrate the sun's rays by up to a factor of 5,000. (PSI) PSI
These solar cells by Flisom, a spin-off of the Federal Institute of Technology Zurich, are lightweight and flexible. (Keystone/Gaetan Bally) Keystone
The Spirit of Biel-Bienne won the World Solar Challenge for solar-powered vehicles in Australia in 1990. (Keystone) Keystone
A picture montage showing the Swiss solar submarine "Goldfisch", a project presented in 2008. (Keystone/Photopress/BKW) Keystone
A solar-powered kick scooter was available to visitors to the Expo.02 in 2002 (Keystone/Sandro Campardo) Keystone
The Tour de Sol in Switzerland was the first rally for sun-powered vehicles. It ran annually from 1985 to 1993. (RDB/Felix Aeberli) RDB
The solar catamaran MS TÛRANOR PlanetSolar has almost 540m² of photovoltaic solar panels (Keystone/Dominic Favre) Keystone
The sun-powered plane Solar Impulse completed its first night flight in July 2010 (Keystone/Dominic Favre) Keystone
The Monte Rosa Hut is designed to obtain 90 per cent of its power needs from the sun (Keystone/Martin Rütschi) Keystone
Bern’s Stade de Suisse has one of the largest solar rooftops in the world (Keystone/BKW/Stephan Bögli) Keystone
Solar panels on skyscrapers on the outskirts of Muri, near the Swiss capital, Bern (Keystone/Gaetan Bally) Keystone
An environmentally friendly house in Nesslau, northern Switzerland, which has solar panels to heat up the water (Keystone/Gaetan Bally) Keystone