There are close to 50,000 merchant ships in the world's oceans they transport 90% of international trade and contribute 2.2 percent of emissions to the atmosphere. That's as much as a large industrialized nation.
But the shipping industry doesn't have any plans to reduce its huge environmental impact and nobody's forcing it to.
The Estrada is a Finnish cargo ship that sails the North Sea six times a week. But it's not just any ship. For the past three years it's been at the center of an experiment aimed at reducing shipping fuel consumption; and those huge cylinders that sit on top of it, known as rotor sails, are the innovation that's making this possible. Thomas risky is the CEO of Norsepower, a Finnish startup that specializes in green technology for the shipping industry. It's the company that built the cylinders.
These are Norsepower rotor sails; so they are producing forward thrust to the ship as mechanical sails and saving in the fuel cost of the ship. It just doesn't look like a sail or like a wing. We can produce the same lift with a lot smaller sail area. So this is the most efficient way to build a sail.
The principle that allows this to work is called the Magnus effect. When wind hits the cylinders they spin really fast. That movement creates a difference in pressure between the front and the rear of each cylinder - which is exactly what happens with airplane wings just on a different axis. So in this case, the pressure differential pushes the ship forward. The end result is that the Estrada uses less fuel than it would without the sails.
The first rotor sails were built in the 1920s but it wasn't until recently that materials became advanced enough to make them economically viable.
How much fuel do you save when these rotor sales are going full power?
In long term average to save roughly 400 tons of fuel per year; That's equaling more than 1,000 tons of co2 emissions per a year. On an average trip how much money do these sales actually save the owners of the ship?
Roughly 400 USD per everyday 400 dollars per day might not sound like a lot for a shipping company; but if you're saving that much every day across an entire fleet it could have a real impact in a business like shipping which has seen huge losses in recent years.
We are for example fitting a tanker owned by Maersk - biggest shipping company of the world in the next year with two pieces of 30-meter rotor sails. So those are huge. These are only 18 meters tall per piece.
Tristan Smith is a low-carbon shipping researcher at University College London.
Could we potentially one day see a ship powered by these rotor sails and biofuels and not have any kind of heavy fuel oil involved at all.
We could do that today. The technology is - I mean this in some ways this is why it's so frustrating to see how slowly things are moving because none of the technology needed to make a zero-emission ship does not exist today in some form. The problem is that the commercial driver to ensure that the investment goes into mature the technologies, just isn't there at the moment. Without clear regulation that says this is how fast we're moving, this is when you're going to meet these standards, and without a very high oil price, there isn't the incentive to move to the alternative solutions.