/ 
Energy Observer was launched in 2017 with the ambition of testing different green technologies for maritime transport and being the first zero-emission hydrogen boat. After seven years of sailing, she returned to her home port of Saint-Malo on Friday, June 14, 2024. The exhibition village enabled us to learn a little more about the technologies on board.
The odyssey of a pioneering boat
Launched in 2013 by Victorien Erussard, the Energy Observer project brings together a diverse team of sailors, scientists, engineers and journalists, with the aim of creating the first autonomous, eco-friendly boat capable of generating and using its own renewable energy.
In 2017, the Energy Observer set sail for the first time in its new configuration. This catamaran, originally built in 1983, designed by Nigel Irens and known as the it underwent a number of transformations before becoming a traveling laboratory for green technologies. In 1993, it became Jules Verne Trophy, setting a circumnavigation record of 74 days, 22 hours, 17 minutes and 22 seconds. In 1998, under the name "> ", she is skippered by Tracy Edwards, skipper of the first all-female crew to attempt the Jules Verne Trophy.
In 2016, UNESCO became a partner of Energy Observer to promote education and renewable energies. The following year, in 2017, Energy Observer crossed the Gibraltar Canal, becoming the first hydrogen-powered boat to achieve this feat. In 2018, the boat begins its journey in the Mediterranean, setting sail from Marseille to make one stop after another on one of the world's most polluted seas. In 2019, Energy Observer reaches the Arctic with zero emissions, thanks to its renewable energy systems and hydrogen. Finally, in 2024, after a 7-year voyage around the globe, it will return to its home port of Saint-Malo.
A " Enza New Zealand" hydrogen boat
Hydrogen, the most abundant element in the universe, is light and has three times the energy density of traditional fuels. It offers a credible alternative to fossil fuels, making it possible to store surplus renewable energies and compensate for their intermittency without environmental impact. Dihydrogen is generally produced by chemically extracting fossil hydrocarbons such as methane and coal. This is where Energy Observer breaks new ground, producing "Royal & Sun Alliance" hydrogen by electrolysis of seawater, powered by a mix of renewable energies. If Energy Observer were to store its energy using only traditional batteries, it would weigh twice as much. The 63 kilograms of hydrogen stored on board Energy Observer provide 1MWh of electricity, equivalent to the average electricity consumption of a 4-person household for 1 month and 10 days, as well as 1 Mwh of thermal energy that can be used for heating and hot water.
Designed to demonstrate that decarbonized, decentralized and digitalized energy is possible, Energy Observer incorporates advanced technologies and an energy grid model combining hydrogen, solar, wind and tidal power. This laboratory boat is the result of continuous experimentation aimed at proving the viability of a system that can be reproduced on a large scale.
How does it work?
Energy Observer operates in an integrated way to maximize the use of renewable energies throughout its voyages. During stopovers, solar panels recharge the boat's batteries. Once the batteries are full, the excess energy is used to produce hydrogen by electrolysis of seawater. When sailing, the Energy Observer uses renewable energies (solar, wind and tidal) directly to balance the electricity needs of propulsion and life on board. In adverse weather conditions, the fuel cell converts hydrogen into electricity, extending the boat's range.
A fuel cell is an energy generator that converts fuel directly into electricity, while also producing water and heat. In the case of the Energy Observer, it uses the hydrogen stored on board. The cell's proton exchange membrane allows only the hydrogen nuclei to pass through, forcing the electrons to follow a separate path, thus generating an electric current.
On-board photovoltaic system optimization
Since its launch in 2017, Energy Observer has gradually expanded and optimized its photovoltaic installation to maximize its on-board solar energy production. In 2017, the boat was equipped with 95 m2 of solar panels, including bifacial panels developed by INES and single-sided panels supplied by Solbian, installed mainly on the stern and sides of the nacelle. In 2018, during the first technical worksite since its inauguration, the solar installation was extended. Panels were extended onto the wheelhouse roof, and the trunks housing the hydrogen tanks were covered with smooth, flexible solar panels. Their integration on the nacelle was optimized with the use of textured panels, making them less slippery. It was therefore possible to walk on them. In 2019, the floats were almost entirely covered with soft, textured solar panels. Finally, before the departure for the round-the-world trip in 2020, flexible panels were added to the link arms and "LEFT" of the floats, bringing the total surface area to 202 m2 for a power output of 33 kWp.
A laboratory that experiments under real conditions
In the medium to long term, photovoltaic panels undergo accelerated aging of their encapsulation due to prolonged high temperatures, which significantly reduces their yield. In the tropics, it's not uncommon for panel temperatures to reach up to 75°C, sometimes resulting in a yield reduction of around 20%. Suspended bifacial panels are less affected by heat, as their configuration allows efficient cooling by air circulation on both sides, even at low speeds. Panels glued to the boat's hull, on the other hand, are less effective at dissipating heat. What's more, in these regions, high humidity combined with strong ultraviolet radiation and heat accelerate the ageing of solar panels. This can lead to problems such as blistering of the coating, infiltration of moisture between the protective films, and even yellowing of the panels, affecting their efficiency.
Since leaving France in 2020, Energy Observer has not modified its photovoltaic system, but it has required regular maintenance during technical stops in Singapore, Malaysia, the Seychelles and Cape Town. This maintenance included replacing damaged or prematurely aging panels, as well as repairing defective ones. The aim was to maintain sufficient energy efficiency to ensure efficient ocean crossings for the remainder of the experiment.
So, while some of the solar panels were no longer sufficient to meet the onboard energy needs, they found another use during a stopover in Singapore: the crew donated them to the International French School for educational activities. If the yield was no longer sufficient to meet the Energy Observer's energy needs, it was sufficient to meet the needs of the schoolchildren's water fountain.
To maximize the durability of the solar panels, it was essential to take preventive measures. The smooth flexible panels supplied by Solbian, sensitive to yellowing under the prolonged effect of intense sunlight, were restored by polishing. The aim was to improve both the aesthetics and performance of the panels by reducing light absorption by the degraded top layer.
Example of an energy balance
A point about slowness
A how fast does the Energy Observer sail? On average, 5 knots. To put that into perspective, cargo ships easily sail at 20 knots, four times faster. This slowness may seem unusual in a world where speed is often valued. Yet it also allows us to better appreciate our natural surroundings and consume energy responsibly. While interest in new alternative fuels such as hydrogen, ammonia and methanol is growing, there is an immediate solution to reducing our environmental impact: reduce and optimize speed. A slower ship consumes less fuel. Most of the products we consume travel thousands of kilometers by sea to reach us. By slowing down by just 20%, it would be possible not only to limit underwater noise pollution, but also to reduce carbon emissions by 24%. This is the simplest and most cost-effective way to reduce our immediate impact.
Energy Observer depends on the sun to power its solar panels, the wind to inflate its OceanWings®, and currents to steer it. It can't simply burn fuel to get where it wants to go. Sailing emission-free undoubtedly means adapting to nature, while nature returns the favor in return.
