A solar-powered plane has successfully returned to Abu Dhabi after 16 months, completing the first fuel-free flight around the world in a demonstration of the potential of renewable energy.
The plane, Solar Impulse 2, touched down in the United Arab Emirates capital at 4.05am local time (12.05pm NZ).
In a journey that began on 9 March 2015, it flew about 40,000km around the globe over nearly 500 hours.
Unfavourable weather at times hindered smooth flying, causing the plane to be grounded for months in some countries.
Solar Impulse founders and pilots, Bertrand Piccard and Andre Borschberg took turns piloting the aircraft, which has a wingspan larger than a Boeing 747 and weighs only as much as a family car.
Its four propellers are powered solely by 17,000 solar cells on the wings, with four batteries keeping energy stored for night flying.
It reached up to 9000m altitude and had an average speed of 45km/h to 90km/h. The plane had 16 stopovers along the way including in Oman, India, Myanmar, China, Japan, the United States, Spain and Egypt.
The Swiss team were campaigning to support clean energy, partnered with Abu Dhabi green energy firm Masdar. The oil-rich capital of the United Arab Emirates was investing billions in industry, tourism and renewables to diversify its economy.