Circumnavigating the globe with solar power seems to be a Swiss pastime. Currently, a solar-powered catamaran sailing under the Swiss flag is attempting to find a sunny course across the oceans – with a little help from German technology between the sun and the sea.
Is it the lack of a coastline, the dark shadows in the deep valleys, or the mountains blocking the horizon? For some strange reason, the Swiss just love to circumnavigate the globe with solar power – and set world firsts in the process. In 2008, the Swiss teacher and environmentalist Louis Palmer was the first to drive a solar car around the World. For 2013 Bertrand Piccard, another Swiss citizen, is planning to fly around the world with the Solar Impulse (see engine 1/2009). But land and air are not enough. Currently, the Tûranor, a solar-powered catamaran, is carrying the Swiss flag to the seven seas in an attempt to sail around the World – another first.
Well, sort of. Relying on the sun for long sea voyages is, strictly speaking, nothing new. What Planet Solar, the team behind the Tûranor, is trying to accomplish was already done some 400 years ago – if you count the wind as a direct result of the sun’s power. From 1519 to 1522, the fleet of Magellan – from Portugal, by the way, Switzerland – was the first to prove that the Earth is round. The first engine-powered boat to do the trip was, in 1847, the paddle steamship HMS Driver of the Royal Navy. Then the Diesel engine came along and everything started to go downhill. Today, the exhaust fumes of more than 100,000 commercial ships are darkening the sun.
It was this pollution which fuelled the vision of Raphaël Domjan. His dream was to achieve the first round-the-world sea voyage powered by solar energy. “I want to prove it is possible”, explains the adventurer from Neuchâtel. In 2004, the engineer, paramedic, high mountain guide and owner of a company that runs solar-powered computer servers founded the Planet Solar Project: “We want to be the Philéas Fogg of the 21st century. But beyond Jules Verne’s dream, our project is to resolutely serve humanity and the environment and to overtake the possibilities of fossil fuels, called classical energies.”
With today’s technology, and compared to a container ship carrying over 10,000 containers, a solar boat can be nothing more than a proof of concept. But even the smallest idea, especially when it has proved to be feasible, can raise awareness and spark a change.
To see his vision come true, Domjan assembled an impressive team of experts and sponsors, which in just six years managed to build a boat, test it and send it on its journey around the globe.
The Power of the Sun
The boat’s name, Tûranor, is derived from J.R.R. Tolkien’s Lord of the Rings and translates into ‘The Power of the Sun’. And power it has: Almost 540 square metres of solar modules mounted on the top deck, two side riggers and a ‘rear wing’ produce 93.5 kilowatts of electrical power. With a length of 31 metres and a width of 15 metres, the catamaran is the largest solar boat ever built. Its designer, New Zealander Craig Loomes, is no stranger to nautical records: One of his creations, the Earthrace (see engine 1/2008), holds the world record for a power boat circumnavigation in a little less than 61 days. Just like the Earthrace, the Tûranor is designed according to the so-called ‘wave-piercing’ concept, where the boat ‘slices’ through the waves. This uses less energy than is required for conventional concepts, where the boat ‘rides’ the waves. But this is where the similarities end. Whereas the Earthrace was built for speed, the Tûranor is built for efficiency. Extensive tow-tank and wind-tunnel testing was undertaken to optimise the boat’s performance and reduce its resistance to wind and waves.
Weight is another critical factor. The lighter the boat is, the less energy is needed to propel it using the power from the on-board energy storage. The boat structure itself weighs just around 40 tons – made possible by a light, yet extremely durable carbon-sandwich construction and the expertise of Kiel-based boatbuilding firm, Knierim Yachtbau.
Boatbuilding isn’t the only German know-how which made Domjan’s dream come true. The solar cells, the lithium-ion batteries, the four electric motors with a total output of 120 kilowatts and the two carbon fibre propellers are made in Germany, too. It comes as no surprise that on such a unique vessel the propellers are just another oddity. The so-called Vector propellers, developed by a subsidiary of turbo specialist Voith, have a diameter of almost two metres. Since their surface-piercing blades, originally designed for river vessels, are highly efficient at slow speeds, they are ideal for the Tûranor, which reaches a speed of only eight knots. As half the propeller is in the air and the other half underwater, a ‘wheel effect’ is created, which makes it possible to steer the ship without a rudder by simply turning the blades and varying the speed of the individual propellers.
The boat construction was completed in March 2010 and after a few public appearances and a successful test phase, the Tûranor ‘set sun’ for its historic voyage on the 27th September, 2010 in Monaco. On the 50,000-km cruise, the crew will cross the Atlantic, the Panama Canal, the Pacific, the Indian Ocean and the Suez Canal to reach the Mediterranean. But the exact course is dictated by the sun. “During our round-the-world tour, we will have to manage whatever energy nature gives us,” explains Raphaël Domjan. “We will have to constantly optimize our route and speed in line with the available sunshine and the medium-range weather forecast. No one has ever undertaken such a task.”
The Light at the End of the Atlantic
So far, skipper Patrick Marchesseau and the rest of the crew of six have been successful in their sun-seeking. They arrived in Saint Martin on the 18th November to bag their first record: the fastest crossing of the Atlantic with a solar boat, a record previously held by ‘Sun 21’, which also managed the first ever solar crossing. In 2007, it took the team of environmentalists and adventurers from, you guessed it, Switzerland a little more than 29 days to Saint Martin. Now the Planet Solar team has beaten their fellow countrymen by 2 days, 13 hours and 20 minutes.
The journey across the big pond was relatively quiet. With lots of sun and only a few cloudy days, the Tûranor, capable of sailing three days without recharging, never ran out of steam – or sun to be precise. The crew had only minor problems to deal with, like an unbearable 41 degrees Celsius in the cockpit on sunny days, or overheating solar panels. If not cooled by a gentle ocean breeze, the efficiency of the cells is reduced by ten percent or more. Boatswain Jens Langwasser developed a very special cooling method to keep up his own efficiency: Towed by the boat, he practised solar surfing – probably another first.
After a stop in Cancún, Mexico, to pay a visit to the Climate Change Summit held there in December, the solar catamaran will pass through the Panama Canal and head into the endless blue of the World’s largest ocean. The Pacific, too, has already been crossed by a solar boat. In 1996, Kenichie Horie, the Japanese godfather of the Planet Solar project, left Salinas in Ecuador to arrive 148 days later in Tokyo after a non-stop voyage of 15,000 kilometres. This is also the longest distance ever covered in a solar boat, another record the Tûranor will attempt to break along the way.
But Project Solar is not all about breaking records and setting firsts. It’s mainly a huge promotion campaign for renewable energy. “We want to help drive forward the development of sustainable energy technologies on the water and in other mobile applications”, says boat owner and entrepreneur Immo Ströher. The goal is to offer future-proof solutions for sustainable living and environmentally responsible mobility concepts and, according to Ströher, “solar mobility can make a significant contribution to this endeavour”. Consequently, he is planning ahead. A subsidiary of his energy management company Immosolar is already working on a meaningful utilisation concept when the scheduled circumnavigation has been completed. One of the ideas is to use the Tûranor as a cruise boat for educational seminars or conferences – maybe on a Swiss lake.
Webseite des Planet Solar Projekts mit ausführlichen Informationen, Bildern, Filmen, dem aktuellen Kurs der Tûranor und täglichen Logbook-Einträgen.
Internetpräsenz von Lomocean, dem Unternehmen von Craig Loomes, der neben der Tûranor noch andere, ungewöhnliche Boote entworfen hat.
Die deutsche Werft, die den Solarkatamaran gebaut hat.
Bei Voith Turbo Advanced Propeller Technologies entstand der Propeller für die Tûranor.
Der Geschäftsführer von Immosolar, Immo Ströher, ist Eigner der Tûranor und einer der Hauptsponsoren des Projekts.