First-Ever Zero-Fuel Plane Completes its Worldwide Journey

With the power of PV solar panels and IoT technology, the plane is capable of flying for days without fuel.

Solar Impulse 2, the Internet of Things (IoT) solar-powered plane, completed the last leg of its worldwide journey—a feat people thought to be impossible just 15 years ago. With 17,000 photovoltaic (PV) cells on its wings, the zero-fuel flying machine may be the start of a green revolution in aviation technology.

The plane has a wing span of 72 m, while only weighing as much as a typical SUV, plus one pilot. It is approximately 5,000 pounds, of which about 800 pounds is made up of advanced lithium polymer batteries.

The high-energy storage capacity is what allows the plane to fly both day and night. The longest leg of its worldwide journey was from Nagoya to Hawaii, a distance of 8,924 km that took four days and 21 hours.

Solar Impulse 2 (also called Si2) before takeoff. (Image courtesy of Solar Impulse.)

Solar Impulse 2 (also called Si2) before takeoff. (Image courtesy of Solar Impulse.)

There is another feature that keeps the plane in the air for such long periods of time. Interconnected software with thousands of sensors embedded in the device sends big data to a server on the ground.

The Mission Control Center (MCC) in Monaco remotely monitors the performance and condition of the aircraft’s vital systems using this data. MCC personnel analyse meteorological information surrounding the plane, and even changes to the pilot’s health (heart rate, blood oxygen, etc.).

The Solar Impulse 2 flies over the Sheikh Zayed Mosque at the beginning of its flight in Abu Dhabi, March 2015. (Image courtesy of Solar Impulse.)

The Solar Impulse 2 flies over the Sheikh Zayed Mosque at the beginning of its flight in Abu Dhabi, March 2015. (Image courtesy of Solar Impulse.)

With this constant stream of information, the team at the MCC calculates the most optimal flight paths using simulation software. This helps to ensure that the plane runs efficiently and safely.

The controls within the plane, however, are a little less advanced. The pilot manually flies the plane during the entire route, and only takes 20 minute naps when the weather is clear.

During the pilot’s rest, an autopilot is engaged, but it is more primitive than conventional plane navigation tools. While the plane is in motion, the autopilot can keep the plane on a steady course, but the actual pilot must take over the controls for most of the flight.

Solar Impulse 2 Breaks Record

On July 26th, Solar Impulse 2 landed in Abu Dabi at 4:05 am, local time. With this final landing, the plane was officially the first solar-powered aircraft to have circumnavigated the world. 

Above is a simplified flight path of the Solar Impulse 2. (Image courtesy of Solar Impulse.)

Above is a simplified flight path of the Solar Impulse 2. (Image courtesy of Solar Impulse.)

The distance was short compared to its trek across the Atlantic Ocean just a few weeks before, but the journey was treacherous nonetheless. The Middle Eastern extreme heat brought temperatures so high that it reached the limits of the tiny plane’s design requirements.

The total journey across the world amounted to 23 days in the air and was 43,041 km over 17 separate segments.

To see footage of the plane and its journey across the world, see the Solar Impulse website.