Sails return as shipping tries to go green

As the shipping industry faces pressure to cut climate-altering greenhouse gases, one answer is blowing in the wind.

European and US tech companies are pitching futuristic sails to help cargo ships harness wind power. While they sometimes don’t even look like sails — some are shaped like spinning columns — they represent a cheap and reliable way to reduce CO2 emissions.

“It’s an old technology,” said Tuomas Riski, the CEO of Finland’s Norsepower, which added its “rotor sail” technology for the first time to a tanker in August. “Our vision is that sails are coming back to the seas.”

Denmark’s A.P. Moller-Maersk is using its Maersk Pelican oil tanker to test Norsepower’s 30 meter spinning columns, which convert wind into thrust based on an idea first floated nearly a century ago.