Energy Observer: Was an ocean racer, became a technological marvel

Few boats have had such a rich and varied history in the past 40 years as this one, now known as the Energy Observer.

Would Nigel Ayrens and Mike Birch, the boat's creators, recognize her today? The narrow noses of the Formule TAG, now the Energy Observer, remain the hallmark of this famous ocean yacht, but much more has changed over the years.

In 1983, the 80-foot Formule TAG was launched as part of a revolutionary new generation of multihull boats designed for ocean racing and record breaking.

At that time, it was the largest ocean racing catamaran of its kind built using aerospace technology. The following year, he broke the 24-hour race record with 512.5 miles.

In 1993, it was bought by Peter Blake and Robin Knox-Johnston to try to win the Jules Verne Trophy, famed for a spinnaker decorated with bright red and green apples called ENZA (Eat New Zealand Apples). 

The second attempt, in 1994, was crowned with success, and the ship set a record for circumnavigation with a crew - 74 days.

The next was Royal & SunAlliance, skippered by Tracy Edwards. Although Jules Verne's trophy proved elusive, Edwards and her team broke seven world records.

Then Tony Bullimore took over, lengthening the yacht's hull to 100 feet and running under the name Team Legato in Bruno Peyron's 2000 round the world race: The Race.

In 2010, it capsized at Cape Finistère in a 15-knot wind. Many believed that the boat would never recover from such an accident: too old for racing, too damaged to be repaired.

New target

However, French entrepreneur Victorien Heroussard, who has sailed everything from Hobie cats and Formula 18 to Route du Rhum and Transat Jacques Vabre, had a different idea.

His goal was to build the first self-sufficient vessel on the 100%. The chassis of the former ocean racing catamaran was the ideal platform, and the rework of the existing boat perfectly matched the project's ambitions.

Since the launch of the Energy Observer in 2012, the project has been under continuous development and has traveled over 30,000 miles to date.

The Energy Observer team believes that for a vessel to become a truly zero-emission boat, capable of sailing from the Arctic Circle to the equator, it needs a combination of energy sources.

“The variety of sources increases reliability, productivity and safety,” says Louis-Noelle Vivies, general manager of the project.

The main driving force on board is provided by two 45 kW electric motors. They are impressive in size and are not used at maximum power, therefore they provide high efficiency.

Choosing a single battery capable of powering them for a long period of time without recharging would lead to a reduction in the weight of the project. Instead, the Energy Observer uses two small battery packs with a total capacity of 100 kW, which is also safer.

The weight of this hybrid solution is still 1.4 tonnes.

In the future, thanks to the development of lighter batteries, this weight should be halved for the same power.

Batteries act as a buffer between the motors and the four different energy sources needed to provide a 24/7 power supply. The most innovative of these is undoubtedly hydrogen.

The battery was developed by project partner Toyota, based on the battery used in their hydrogen-powered Mirai.

“It delivers 10 times more power for the same weight than other batteries on board,” says Vivies. “There are two hydrogen batteries, one in each case, with a peak power of 80 kW.”

Although they are now three times cheaper than the original first generation batteries, hydrogen batteries are still twice as expensive as a generator of the same capacity.

On the other hand, they are guaranteed for 80,000 hours, do not require maintenance and have no associated fuel costs, as the Energy Observer produces (by desalination, purification and electrolysis) and stores in eight tanks of 64 kg of its own hydrogen from seawater.

The battery efficiency is 2.5 times higher than that of diesel fuel when you consider the energy required to extract, process and transport it to the pump.

The battery also generates 50% of heat used on board, so the crew never ran out of hot water and could enjoy a cozy warm interior as they cruise north to Svalbard.

The third source of energy is solar panels, which occupy an area of 202 m² and generate a total power of 35 kW.

 Solar panels use different technologies depending on their location on the deck or superstructure.

Some are double-sided to catch rays reflected from the surface of the water. Elsewhere they are coated with a non-slip polymer that improves performance when the sun is not at its zenith.

Wind power is an area that has undergone significant changes since the launch of the Energy Observer.

After experimenting with vertical wind turbines and a traction wing, the catamaran now carries two Oceanwings, a 32 m² rigid wing designed by VPLP and inspired by the America's Cup experience.

Ocean Wings were designed with the ultimate goal of making maritime transport less polluting, and the Energy Observer is an ideal experimental platform for developing this system.

Almost twice as efficient as traditional sails, the wings can be used to both increase speed and reduce energy consumption in addition to electric motors.

The wings also allow the Energy Observer to use a fourth source of power generation - hydroelectricity from propellers in good winds.

The base platform of the Formule TAG hull was lightweight, only 15 tons. Although the catamaran no longer carries its original installation, additional batteries, motors, etc. increased the final displacement to 30 tons.

Therefore, it was necessary to increase the buoyancy of the hull, which was achieved by imposing a second skin, adding volume below the waterline.

In addition to adapting all of these new technologies to a corrosive marine environment, the Energy Observer team's expertise is in finely managing these various energies by optimizing efficiency.

The choice of the most efficient method of propelling or generating electricity occurs at any given moment, before fine tuning the wings or the pitch of the propellers.

Any innovation often makes a big leap from theory to practice, but this project creates data to prove concepts.

The Energy Observer has been traveling the world's oceans since 2017.

In March 2020, he embarked on a journey to attend the Tokyo Olympics and Dubai World Exhibition in 2021, then return to Paris for the 2024 Olympics.

Over the 2,134 miles traveled on the current voyage, the vessel averaged 6.34 knots, with 83% of power generated for propulsion or navigation and only 17% for residential systems used by the five-member crew on board.

Over the past eight months, solar has accounted for 56% onboard production, hydrogen for 7%, and Oceanwings for 37% of the equivalent consumption of the engines saved.

Hydropower has been little used in intertropical latitudes, but it is expected to be used more frequently in more windy regions.

Energy Observer Specifications:

Length: 30.50m - 100ft 0in,

Width: 12.80m - 42ft 0in,

Draft: 2.10m - 6ft 11in

Displacement: 30 tons,

Sail area: 64m² - 700ft², Designer: Nigel Ayren

23.06.2021