Jérôme Delafosse (foreground), expedition leader, at Tower Bridge, London. Image credit/EO
Energy Observer, an experimental, zero-emissions vessel, has made it to the half point of its round-the-world voyage.
The ship is powered by solar, wind and carbon-free hydrogen, produced by seawater electrolysis.
"The ship's OceanWings wings optimize the energy input of the wind and save energy traditionally allocated to the propulsion of the boat, thus making it possible to produce hydrogen while sailing," the Energy Observer's website said.
"The ship shows that practical alternatives to fossil fuels do exist and can be developed both on land and at sea," it added.
Energy Observer set sail from St Malo on the French Atlantic coast in April 2017 to make a six-year voyage.
Its London stopover ends the northern European leg of the voyage. The vessel is docked at St Katherine's Dock from October 5 to 10 and is open to the public.