Energy Observer is a vessel powered only by energy that it generates itself, be it the onboard solar panels, wind turbines or a hydrogen fuel cell. It’s a floating laboratory, PR stunt and clean-energy evangelist all at once, showing how the future of transportation could be.
Halfway through its six-year journey around the world, the vessel stopped in London so we could learn what’s happened since its voyage started.
“We test and mix a number of different [energy-generation] technologies, but the secret is in the mix,” explained project manager Louis Noël Vivies. The vessel is covered in 168 square meters of solar panels, both laminated onto the shell and in rigid racks over the hull. The latter are double-sided, too, to pick up light reflected from the surface of the water. At peak output, the panels catch 28kW of power, enough to keep the on-board batteries charged.
There is 126kWh of batteries on board: 100kWh for the motors, and a further 26kWh for crew comfort. That includes light, heating and the ship’s labor-saving devices, including a coffee machine, dishwasher and washing machine. The 100kWh battery supplies two 45kW propellers that can push the boat around at a top speed of 11 knots per hour.
When the batteries drop below 60 percent, the hydrogen fuel cell kicks in, replenishing the lost power to ensure continuous running. It’s here, as a way of bridging the gaps inherent in using renewables, that hydrogen makes plenty of sense as a power source. And using hydrogen to power a boat is pretty logical, since there’s an (apparently) inexhaustible supply of it in the water.
To do this locally, the EO is equipped with a desalinator, electrolyzer and a compressor. The water needs to be purified before having its hydrogen and oxygen separated, with the former being stored in a 62kg tank under 300 bar pressure. According to Vivies, 62kg worth of hydrogen is capable of running the ship for “three days, including creature comforts.”