In pictures: The amazing journey of Solar Impluse 2

Here we look at some of the best images from the different stages of its journey

A solar-powered aircraft successfully completed the first fuel-free flight around the world on Tuesday, returning to Abu Dhabi after an epic 16-month voyage that demonstrated the potential of renewable energy.

The plane, Solar Impulse 2, touched down in the United Arab Emirates capital at 0005 GMT on July 26. It first took off from Abu Dhabi on March 9, 2015, beginning a journey of about 40,000 km (24,500 miles) and nearly 500 hours of flying time.

Bertrand Piccard and Andre Borschberg, the Swiss founders of the project, took turns piloting the aircraft, which has a wingspan larger than a Boeing 747 but weighs no more than an average family car. "More than an achievement in the history of aviation, Solar Impulse has made history in energy," Piccard, who piloted the plane on the last leg, told a large crowd on landing.

He said the technologies used on Solar Impulse 2 could be used on the ground in daily life to halve emissions of carbon dioxide, the main greenhouse gas blamed for climate change. The propeller-driven aircraft's four engines are powered by energy collected from more than 17,000 solar cells built in the wings. Excess energy is stored in batteries.

Here we look at 20 pictures of the amazing journey of Solar Impulse 2.

Solar Impulse's Chief Executive Officer and pilot Andre Borschberg flies in the solar-powered HB-SIA prototype airplane during its first successful night flight attempt at Payerne airport July 8, 2010. PHOTO: REUTERS

German test pilot Markus Scherdel steers the solar-powered Solar Impulse 2 aircraft with the Mont-Blanc in background during a training flight at its base in Payerne, September 27, 2014. PHOTO: REUTERS

Solar Impulse 2, the solar powered plane, piloted by Swiss pioneer Andre Borschberg is seen during the flyover of the pyramids of Giza on July 13, 2016 prior to the landing in Cairo, Egypt. PHOTO: REUTERS

Solar Impulse 2, the solar airplane, piloted by Swiss adventurer Andre Borschberg, flies over the Statue of Libery in in New York, U.S., June 11, 2016 shortly before landing at John F. Kennedy airport. Leg 14 was the shortest so far on the planes trip around the globe. PHOTO: RUETERS

Selfie picture shows Swiss pioneer Bertrand Piccard during the last leg of the round the world trip with Solar Impulse 2 over the Arab peninsula, July 25, 2016. PHOTO: REUTERS

The solar airplane, piloted by Swiss adventurer Andre Borschberg, flies over Manhattan, U.S. on June 11, 2016 shortly before landing at John F. Kennedy airport. Leg 14 was the shortest so far on the planes trip around the globe. PHOTO: REUTERS

A view of the Solar Impulse 2 on flight after taking off from Al Bateen Airport in United Arab Emirates. PHOTO: REUTERS

The solar-powered plane piloted by Bertrand Piccard of Switzerland, flies over the Golden Gate bridge in San Francisco, California, U.S. April 23, 2016, before landing on Moffett Airfield following a 62-hour flight from Hawaii. PHOTO: REUTERS

Solar Impulse 2 takes off from Cairo, with Piccard at the wheel. PHOTO: CHRISTOPHECHAMMARTIN/REZO/IMPUL/THE GUARDIAN

Before landing at San Pablo airport in Seville, southern Spain June 23, 2016. PHOTO: REUTERS

The team completed a record-breaking longest solar flight across the pacific from Nagoya, Japan to Hawaii - 117 hours and 52 minutes.PHOTO: SOLAR IMPULSE/THE GUARDIAN

The plane circles above Nagoya airport in Japan before a planned landing, June 1, 2015. PHOTO: REUTERS

Picture taken by Swiss adventurer Andre Borschberg onboard Solar Impulse 2 (Si2) during the flight from Tusla to Dayton shows the Mississippi river at sunset, May 21, 2016. PHOTO :REUTERS

Solar Impulse 2 is seen over the Red Sea during the last leg of the round the world trip, July 23, 2016. PHOTO: REUTERS

The journey across the US was made in six stages. Here the plane waits in Dayton, Ohio before flying to Pennsylvania then finally on to New York. PHOTO: SOLAR IMPULSE/ THE GUARDIAN

Solar Impulse flies from Seville to Cairo, passing over PS10 solar power plant. PHOTO: SOLAR IMPULSE/ THE GUARDIAN

The plane is seen before landing in Abu Dhabi to finish the first around the world flight without the use of fuel, United Arab Emirates, July 26, 2016. PHOTO: REUTERS

The plane is seen before landing in Abu Dhabi to finish the first around the world flight without the use of fuel, United Arab Emirates, July 26, 2016. PHOTO: REUTERS

Pilots Andre Borschberg (L) and Bertrand Piccard celebrate after arriving on Solar Impulse 2, at an airport in Abu Dhabi, United Arab Emirates July 26, 2016. PHOTO: REUTERS

Pilot Andre Borschberg (R) and Bertrand Piccard gesture during a news conference after their arrival of Solar Impulse 2 in Abu Dhabi, United Arab Emirates July 26, 2016. PHOTO: REUTERS