Construction of the composite structure of the Solar Impulse plane.

Solar Impulse

In a world depending on fossil energies, the Solar Impulse project is a paradox, almost a provocation: it aims to have an airplane take off and fly autonomously, day and night, propelled uniquely by solar energy, right round the world without fuel or pollution.

Solar Impulse's ambition is to contribute in the world of exploration and innovation to the cause of renewable energies. To demonstrate the importance of the new technologies in sustainable development, and of course, once again, to place dream and emotion at the heart of scientific adventure.

The Solar Impulse is a revolutionary concept that will push back the limits of our knowledge in the field of materials, energy management and the man-machine interface. It is an aircraft with an inordinate wingspan for its weight and of an aerodynamic quality that to this day has not been equaled, capable of tremendous resistance, despite its light weight.

The design of the aircraft, pure and futuristic, will itself be the symbol of the spirit of the project in the sky. The question of energy determines the whole project, from the structure’s dimensions to the extreme weight constraints. At midday, each m2 of land surface receives the equivalent of 1000 Watts, or 1.3 horsepower of light power. Over 24 hours, this averages out at just 250W/m2. With 200m2 of photovoltaic cells and a 12 % total efficiency of the propulsion chain, the plane’s motors achieve no more than 8 HP or 6kW – roughly the amount of power the Wright brothers had a available to them in 1903 when they made their first powered flight. And it is with that energy, optimized from the solar panel to the propeller by the work of a whole team, that Solar Impulse is striving to fly day and night without fuel!

An unachievable goal without pushing back the current technological limits in all fields...

Source: Solar Impulse