High tech rotor sails complete with weather stations could be the answer to cutting shipping emissions, reports Eric Marx
The shipping sector’s interest in “sail tech” took on greater urgency after the International Maritime Organization reached an agreement last April to slash emissions by 50% by 2050.
“Just in the last six to 12 months we’ve seen a significant groundswell of support,” said Gavin Allwright, secretary of the International Windship Association (IWSA), a membership organisation that promotes wind propulsion for commercial shipping and boasts over 100 members.
In the past year there’s been a threefold increase in rotor-sail installations, with 14 rotors fitted on six vessels, said Allwright.
This is not about guys with shaggy beards and pipes pulling in the rigging. These are all computer-operated
Rotor sails have a large spinning cylinder amidship. Wind hitting the rotor creates a vertical force that reduces the power requirement from a ship’s main propellers, a phenomenon known as the Magnus effect.
“This is not about guys with shaggy beards and pipes pulling in the rigging,” said Allwright. “These are all computer-operated, with weather stations on vessels helping to get the maximum utility from the rigs.”
Last April, the Finnish shipping company Viking Line’s M/S Viking Grace, which was the first passenger ferry to run on liquified natural gas, became the first passenger ferry to be fitted with a rotor sail, made by Finland’s Norsepower.
Up to that point most of the installations had been on tankers, general cargo ships and bulk freight carriers.
The Peace Boat project, which aims to build the world’s most sustainable cruise ship, the Ecoship, will be fitted with 10 retractable sails, which together will be expected to produce an average of 4% of the 55,000-ton boat’s propulsion power.
And Chantiers de l’Atlantique (formerly STX France) has unveiled plans for a new line of hybrid wind and dual-fuel cruise vessels, the largest of which will be the 190-metre Silenseas, carrying 300 passengers and 80 crew.
Wind propulsion promises up to a 50% fuel saving for new build vessels'
“The entire industry has had its eyes on the cruise sector, for two main reasons,” said Allwright.
One, is its profitability, which at the moment far surpasses the commercial freight segment. Second, is its interface with the public.
The question is whether wind propulsion can deliver on its promises: between 10%-30% fuel savings on retrofits, and up to 50% for optimised new builds, meaning a renewable energy source, free and abundant delivery at the point of use.
It’s a massive number compared with savings offered up by other alternative fuels and renewable energy options, which are typically working on one to two per cent changes.
“There's a lot of industry scepticism,” Allwright acknowledged.
But with large companies like Maersk, Airbus and Renault all pursuing various wind-propulsion initiatives, Allwright said there’s now both high visibility and a backbone of support in the form of access to capital.
The EU Commission says the market for wind propulsion could be 10,000 installations by 2030
Small sail carbon vessel projects are slated for lift-off through EU funding programmes for cross-border renewable projects. A wide range of projects, not just for rotors but also for hard and soft sails, are currently under way.
Third-party verification tools for wind-technology uptake are being developed, alongside wind-propulsion hubs that will cluster together wind-propulsion technology developers, engineering firms, research institutes, shipping companies and ship builders.
A 2017 EU Commission report forecasts the market potential for wind propulsion in 2030 to be upwards of 10,000-plus installations, primarily on bulkers and tankers.
“That’s just in 12 years’ time,” said Allwright, who noted the report’s arrival in 2017, prior to the industry’s renewed focus on decarbonisation. “The market is just starting to kick in,” he added.
This article is part of the in-depth Sustainable Tourism briefing. See also: