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Marine Propulsion & Auxiliary Machinery

Marine Propulsion & Auxiliary Machinery

Self-fuelling vessel sets sail

Wed 16 Aug 2017

Self-fuelling vessel sets sail
Energy Observer is set to visit 50 cities worldwide

A new experimental vessel could offer solutions for emission-free ships of the future

In environmental and economic terms, a vessel that powers itself while carrying no fuel would appear to represent the Holy Grail as far as most ship designers and owners are concerned. The fact that just such a vessel set sail in July on a six-year global journey is exciting, to say the least.

For commercial shipping, though, the wait continues because the vessel in question is the Energy Observer, a former racing boat that has been converted by a team of nearly 50 engineers, designers and naval architects. Nonetheless, the technologies deployed on the boat may attract considerable interest for commercial shipping in the future. This is becauise the vessel uses a combination of a hydrogen fuel-cell system, solar panels and wind turbines to sail throughout its voyage spanning 50 countries and 101 stopovers.

The Energy Observer has been dubbed the ‘Solar Impulse of the seas,’ recalling the historic solar-powered plane that recently circumnavigated the world. Much like the Solar Impulse project, the Energy Observer is a way of showing how new eco-friendly technologies can be put to practical use. The entire undertaking is intended to be a floating demonstration of an autonomous, self-sufficient seafaring vessel that will be able to indefinitely traverse the globe in all weather conditions.

The Energy Observer project revolves around the desire to find concrete, innovative solutions that help make the case for energy transition.

During the day, the vessel primarily uses sun or wind energy. At night, it harnesses a reservoir of hydrogen that the boat itself produces through electrolysis of the salt water. The team behind Energy Observer claims that it is the first vessel in the world able to produce its own hydrogen on board, from seawater, without greenhouse gas emissions.

This is particularly noteworthy, as around 95 per cent of hydrogen currently used as fuel is obtained using fossil-fuelled energy.

The vessel's primary sources of power are its solar panels and wind turbines, but it is its hydrogen power systems that are the most innovative. First, sea water is desalinated by reverse osmosis. Then it is pumped into a solar-powered electrolyser, which splits water molecules into hydrogen and oxygen. The fuel cell can produce 26 kWh of electrical energy from 1.81kg of hydrogen. The hydrogen fuel will be used at night or whenever there is not enough energy available from the solar panels, wind turbines or kite to power the vessel. The hydrogen is stored in two 62kg capacity tanks in gaseous form.

The vessel’s two electric motors boast efficiency rates of 97 per cent. They are also reversible, being able to double as hydrogenators when the vessel is using wind power. The vessel’s fuel cell generates electricity from the stored hydrogen, acting as a range extender for the vessel.

The vessel also features two vertical-axis wind turbines for power production. Mounted near the stern, these produce up to 3kW of power. Each turbine is 2m high and has been developed specifically for the Energy Observer.

The boat’s kite sail serves a dual purpose: it assists in navigation and generates power. While it is pulling the boat through the water, the ship’s propeller turns an electric motor to create electricity. The system can make 2-4kW of power.

The US$5.25 million, 30.5-metre boat was originally designed in 1983 for racing, and enjoyed success in open-sea sailing before its owners and captains, Frederic Dahirel and Victorien Erussard, teamed up with researchers, engineers, architects, and others to convert it into the Energy Observer project. The boat traded the standard solar battery for its hydrogen tanks, making it almost three times lighter than the last solar-powered boat to circumnavigate the globe, MS Tûranor PlanetSolar. It can move three times as fast, with a top speed of 42 knots. It will typically be cruising at 8 to 10 kts as it makes its planned 101 stopovers in 50 countries all over the world.

“There is no silver bullet to fight against global warming: there are solutions, which we must learn to make work between them,” said Captain Victorien Erussard. “This is what we do with Energy Observer: bring together the energies of nature, but also of our society - bringing together around this boat the knowhow of companies, laboratories, start-ups and institutions.”



Autonomous ships may be governed by an IMO code

Autonomous ships could be regulated through goal-based standards, similar to IMO’s Polar Code that came into effect at the start of this year for Arctic shipping, believes Martin Bergstrom, a naval architect and researcher at Finland’s Aalto University. He hopes to publish a paper by the end of the year outlining how such a code could be drafted.

Mr Bergstrom leads a research group studying the safety aspects of autonomous and Arctic ships. He told Marine Propulsion that, as a new concept in shipping, autonomous ship proposals have much in common with novel Arctic design developments.

He was speaking to Marine Propulsion in June, following an ABB-hosted round-table discussion in Helsinki exploring how increased autonomy in shipping is affecting maritime jobs. He said that an autonomous shipping code would be more complicated to develop than the Polar Code because it would contradict some current legislation, such as the need for a human lookout.

“I see the main challenge with autonomous ships as the functions that are now performed by the crew,” Mr Bergstrom said. Regulations require the lookout to be by sight and hearing, he said, so any goal-based alternative would have to address “in technical terms the functional requirements needed to replace a human being,” he explained.

Current regulations also refer to experience and competence requirements for the lookout, so the code would have to set out how an autonomous ship would achieve the same or better level of function, Mr Bergstrom stated. It would be difficult to prove that this functionality is effective, he added.

In the ABB’s round-table discussion, he had said that the first version of an autonomous ship code would be short, “basically saying that an autonomous ship needs to be as safe as a manned ship. Then it is up to the industry to develop performance-assessment methods that can be used to demonstrate that a design is safe,” he said.

<Mr Bergstrom expects that prototype autonomous ships would be operated within the territorial waters of a supportive flag state to carry out assessments to convince regulators that they are reliable. “It is easy to explain the idea,” he said, and to carry out demonstrations, but “you have to have trust in your assessment.”

This could be a first step toward achieving IMO approval for an autonomous ship code, he suggested. “We are not there yet, but at least we are now starting to discuss it. I think IMO is open to new ideas,” he said. But it will take time, given that “the Polar Code took years to agree,” he pointed out.

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