Following fuel savings figures from Viking Grace, wind power is set to compete as a source of alternative power for passenger ships, says Rebecca Moore
Independent tests to measure fuel savings on Viking Grace following the installation of Norsepower’s Rotor Sail technology mark a turning point for wind power in the passenger ship segment for two reasons.
First, this project is a milestone as the first Norsepower rotor sail trial on a cruise ferry.
Second, while the benefits of wind power are regularly extolled, there have been few concrete figures to show the passenger ship industry exactly what energy savings are available. Even from Viking Line's figures, the savings were not immediately evident for Viking Grace. But now they are.
The test results from independent arbiters NAPA and ABB have shown that Rotor Sail technology offers healthy fuel savings. Following their tests, the teams reviewed the data and isolated an evident change in the propulsion power breakdown of Viking Grace caused by the Rotor Sail. The conclusion was confirmed with a second test, a strain gauge analysis, where forward thrust of the Rotor Sail was measured and converted into propulsion power.
Based on the analyses, the expected long-term change in Viking Grace's annual fuel consumption due to the Rotor Sail is between 231 and 315 tonnes annually, equalling an average propulsion power between 207 kW and 282 kW. As such, Viking Line and Norsepower have agreed to continue collaboratively optimising the Rotor Sail on Viking Grace.
And now that there are solid, even impressive, figures to refer to, momentum will build.
Shipyard Chantiers de l’Atlantique has launched a carbon-free cruise design that uses wind as a main source of power which will also have an important role to play in introducing wind power to ferry and cruise operators. The shipyard used sails to draw on wind power and the yard created the technology to be used with the sails, Solid Sail. This wind technology solution is being trialled on a Ponant cruise ship.
Viking Line is also using two rotor sails on its LNG dual-fuelled newbuild being built in China, doubling the wind power potential compared to Viking Grace to 600 tonnes, and showing the experience gained on Viking Grace is paying off.
Norsepower’s technology has not been used in the cruise ship sector yet, but I believe Viking Grace’s fuel savings will encourage cruise operators to consider this form of power – not least because of the benefit of being seen as environmentally friendly. Towering on deck, the rotor sail is highly visible as an energy-saving device.
With all of the positive news and good PR value, its low cost and accessibility, I cannot imagine it will be long before wind power will become a strong source of power to be used alongside LNG and potentially fuel cells.