The propeller plane, piloted by Solar Impulse Chief Executive Andre Borschberg, has a 61-metre (200-foot) wingspan and is powered by four electric motors. It is designed to fly day and night by saving surplus energy from its 12,000 solar cells in high-performance batteries.
The point of the test flight was to prove that the plane’s solar cells and battery storage are able to keep the plane in the air at night.
The project’s co-founder, Dr. Bertrand Piccard, who completed the first nonstop, round-the-world flight by hot air balloon in 1999, embraced the pilot after he landed the plane to the cheers of hundreds of supporters.
The propeller-driven Solar Impulse, made of carbon fiber, is powered by four small electric motors and weighs around 3,500 pounds. During its 26-hour flight, the plane reached a maximum speed of 68 knots, or 78 miles per hour, the organizers said.
Electric aircraft, including manned and unmanned aerial vehicles, are expected to become platforms for sensors and telecommunications, if their solar panels and batteries can provide enough power to last through the night. AeroVironment, a pioneer in electric aircraft, formed Skytower in 2000, with the intention to develop the high altitude UAVs as “atmospheric satellites”, or high altitude communications relay platforms.
NASA’s Pathfinder and Helios unmanned aircraft broke several records. The Helios Prototype could be configured in two different ways; with batteries and solar cells, or optimized for endurance with a combination of solar cells, storage batteries and a modified commercial hydrogen-air fuel cell system.
The Solar Impulse was the first to show all-electric, 24/7 flight is possible — and with a human pilot. The flight was part of the project’s 100 million Swiss franc ($95 million) effort to eventually pilot the first flight around the globe in an airplane using only solar energy. It is sponsored by Deutsche Bank AG, Germany’s biggest bank.