Solar Planes ?  

Renewable Energy Access has an article about an unusual Swiss experiment to build a solar powered plane capable of flying around the world (though I think we can all consider this highly unlikely to ever scale to jumbo sized planes).

Swiss company Sputnik Engineering has committed to ramping up production of its SolarMax inverters to 400 megawatts (MW) of capacity by the end of 2008. The ambitious target comes as the company is also about to open a new manufacturing facility in Port, Switzerland in March. The company sold devices with a total capacity of 120 MW in 2006, and last year this number rose to 188 MW. In 2008 Sputnik plans to sell inverters with a total capacity of 275 MW.

The company is providing its inverters for two projects that are involved in testing the physical limits of solar energy technology. In the Swiss Alps, the research station at Jungfraujoch is 3,500 meters above sea level. It offers researchers from all over Europe the opportunity to conduct scientific experiments at high altitudes. Currently, physicians from the University of Munich are researching the practical treatment of high altitude pulmonary edema, the Swiss Confederation is monitoring radioactivity in the air and scientists from the Belgian Institute for Atmospheric Research are investigating the chemical composition of the atmosphere.

Since January 11, 2008 the world's highest solar power plant has been helping to power this research. Swiss company sol-E Suisse AG integrated 82 square meters of solar modules into the facade of the research station. By 2009 the company plans to build two or three more systems on other parts of the station. When complete, the system will have an output of approximately 25 kilowatts. The research facility also has solar engineers at work.

“Here we are researching how the atmospheric conditions, the altitude, the temperature and the air density have an effect upon a photovoltaic system,” said Sebastian Vogler from sol-E Suisse parent company, Swiss energy provider BKW FMB Energie AG. “The data are relevant for the SolarImpulse project from Bertrand Piccard.”

Bertrand Piccard's goal is to fly around the world in 2011 using only solar energy to power the flight. SolarImpulse will be the first manned solar airplane that will remain in flight under the cover of darkness. The success of the project depends largely on how efficiently solar energy can be utilized at high altitude.