Norsepower Rotor Sails

[Trafalgar]

I work in the maritime industry and a lot of money is going into developing ways to reduce emissions from ships. One method I came across is "Rotor Sails" which can harness wind power to improve fuel efficiency. Essentially, it works the way spin on a golfball can cause it to rise or curve. According to the manufacturer, it can increase fuel efficiency by 5-7%.

I see some challenges installing using this on many types of ships but I am curious what people in this forum think.

Norsepower Website:

[DavidSh]

I'm not that familiar with the maritime industry myself, but it looks like there would be difficulties rigging any kind of sail on a container ship. Maybe a kite sail would work.

[snowblizz]

I work in the maritime industry and a lot of money is going into developing ways to reduce emissions from ships. One method I came across is "Rotor Sails" which can harness wind power to improve fuel efficiency. Essentially, it works the way spin on a golfball can cause it to rise or curve. According to the manufacturer, it can increase fuel efficiency by 5-7%.

I see some challenges installing using this on many types of ships but I am curious what people in this forum think.

Norsepower Website:

Well, its' rather simple. The ship pictured in the video traffics near me so I've seen this and I know the company operating it. They removed the sail a year (or some such) ago as it didn't really do enough.

So I think it doesn't work in practice.

[Trafalgar]

I'm not that familiar with the maritime industry myself, but it looks like there would be difficulties rigging any kind of sail on a container ship. Maybe a kite sail would work.

One issue I see with any sail is interference with cargo operations. These rotor sails involve putting 30 meter high rotating cylinders on deck. Anemoi, a competitor of Norsepower, is planning on having the cylinders fold down on some bulk carriers they are equipping. Bulk carriers ship iron ore, coal, and solid products like that. I don't see how that would work on container ships, though.

Well, its' rather simple. The ship pictured in the video traffics near me so I've seen this and I know the company operating it. They removed the sail a year (or some such) ago as it didn't really do enough.

So I think it doesn't work in practice.

What kind of ship is that? Was it a ferry or a cargo carrier? Sometimes, governments give grants to install green technology even if it doesn't work well which ship owners use to make additional improvements to the vessel. There are a couple of ferries operating in San Francisco Bay that do this.

Norsepower is claiming a 5-7% increase in efficiency but that is likely only true when the wind is abeam or perpendicular to the ship any deviation from that would require the helmsman to countersteer to keep the ship on course which would cut into the thrust gained.

Of course, I might be misunderstanding the technology. But I think there are more effective ways at reducing ship emissions like having shore ties so ships don't run their generators while in port. Or using alternative fuels like LNG, Methanol, or Ammonia.

[Spacewolf]

One issue I see with any sail is interference with cargo operations. These rotor sails involve putting 30 meter high rotating cylinders on deck. Anemoi, a competitor of Norsepower, is planning on having the cylinders fold down on some bulk carriers they are equipping. Bulk carriers ship iron ore, coal, and solid products like that. I don't see how that would work on container ships, though.



What kind of ship is that? Was it a ferry or a cargo carrier? Sometimes, governments give grants to install green technology even if it doesn't work well which ship owners use to make additional improvements to the vessel. There are a couple of ferries operating in San Francisco Bay that do this.

Norsepower is claiming a 5-7% increase in efficiency but that is likely only true when the wind is abeam or perpendicular to the ship any deviation from that would require the helmsman to countersteer to keep the ship on course which would cut into the thrust gained.

Of course, I might be misunderstanding the technology. But I think there are more effective ways at reducing ship emissions like having shore ties so ships don't run their generators while in port. Or using alternative fuels like LNG, Methanol, or Ammonia.

Containerships have holds below decks as well so it could fold down as well but I suspect this is one of the issues with it, if you lose more than 5% cargo space the sail makes the ship less fuel efficient than not having it, especially as the measure for how ships are being measured by law makers in the EU at least at the moment at least uses cargo carried as one the main divisibles which causes issues for high valve cargos that have low mass.

I suspect the 5-7% is in best case scenario similar to the bubble injection around the hull to reduce drag in the water system that was being talked about afew years ago but that had trouble in anything but calm seas as the bubbles would just be dispersed by heavy seas.

Shore power is good for some types of ships like cruise liners and ships that spend a chunk of their time in port. Not so useful for a ship that might only dock once every 4 months or so.
LNG, Methanol and Ammonia all have difficult storage requirements and need changes to the engines to burn. Again they are useful in certain situations like LNG carriers that can use boil off from the cargo that would otherwise be wasted to power the ship as that's just pure gain and I know afew ships that have dual fuel injectors but not super popular from what I've seen yet. Ammonia in particular is basically a perfect refrigerant yet we still haven't gone back to it yet due to it's issues preferring to invent new less effective refrigerant gases. They also cost vastly more compared to what ships usually burn which is just a step up from road tar on the cracking table and noone else wants.

I think one thing to consider is how efficient ships are considering how much of the worlds trade goes through them the emissions are quite small. The most common pollution reduction fittings do target NOx and SOx production though with Selective catalytic reduction, exhaust washing and direct water injection. Though these all have issues again usually that they reduce overall efficiency meaning your CO2 production goes up.

I don't think the tech that makes ships carbon neutral is here yet, I'll be interested to see what it is in the end though.

[Rockphed]

I don't think the tech that makes ships carbon neutral is here yet, I'll be interested to see what it is in the end though.

sure it is. We have been using nuclear power on ships for half a century at this point. People are just (understandably) leery of giving nuclear reactors to any passing sea hobo, so we only use them on carriers and subs.

[Spacewolf]

sure it is. We have been using nuclear power on ships for half a century at this point. People are just (understandably) leery of giving nuclear reactors to any passing sea hobo, so we only use them on carriers and subs.

Yes I meant a technology that actually has the possibility of getting used.

[snowblizz]

One issue I see with any sail is interference with cargo operations. These rotor sails involve putting 30 meter high rotating cylinders on deck. Anemoi, a competitor of Norsepower, is planning on having the cylinders fold down on some bulk carriers they are equipping. Bulk carriers ship iron ore, coal, and solid products like that. I don't see how that would work on container ships, though.



What kind of ship is that? Was it a ferry or a cargo carrier? Sometimes, governments give grants to install green technology even if it doesn't work well which ship owners use to make additional improvements to the vessel. There are a couple of ferries operating in San Francisco Bay that do this.

Norsepower is claiming a 5-7% increase in efficiency but that is likely only true when the wind is abeam or perpendicular to the ship any deviation from that would require the helmsman to countersteer to keep the ship on course which would cut into the thrust gained.

Of course, I might be misunderstanding the technology. But I think there are more effective ways at reducing ship emissions like having shore ties so ships don't run their generators while in port. Or using alternative fuels like LNG, Methanol, or Ammonia.

The literal ship pictured is M/S Viking Grace. It's a Ro-Ro cruiseliner a type that is very common on Baltic sea routes between Sweden and Finland. It has all the amenities of cruiseliner, but also contains full length cargodeck for EU sized lorries and cars. And funnily enough it is LNG powered. AND they nowadays use landpower while standing still in port.

[Kriegspiel]

sure it is. We have been using nuclear power on ships for half a century at this point. People are just (understandably) leery of giving nuclear reactors to any passing sea hobo, so we only use them on carriers and subs.

The US Navy currently only uses nuclear power on carriers & subs but had a number of nuclear powered cruisers up through the 1990's.

The Russian Navy still maintains two nuclear powered Kirov class cruisers as well as a number of ice breakers which are nuclear powered.

[J-H]

This video from Casual Navigation talks about why sails don't work well on modern ships, including addressing the Magnus Effect (rotor) sails.
Great channel, one of the ones I watch/listen to while doing dishes.

Rotor sails are at about the 3:20 mark.

[Trafalgar]

This video from Casual Navigation talks about why sails don't work well on modern ships, including addressing the Magnus Effect (rotor) sails.
Great channel, one of the ones I watch/listen to while doing dishes.

Rotor sails are at about the 3:20 mark.

Interesting video, but he's wrong on a couple of points.

First, Charterers/Operators DO care about fuel efficiency enough that it effects which ship they hire. A ship with a 10% better fuel efficiency is going to get hired before another, less efficient one because fuel is one of the biggest cost for operators.

Second, He says until "the only way a rule will stick is if it's made internationally through the UN" and says there is no reason for ship owners to change. This shows some serious ignorance of the way international shipping is regulated and the current state of those regulations. Internationally, ships are regulated through the International Maritime Organization or IMO, not the UN. IMO has 175 member nations including every flag of convenience and every world economic power. IMO has mandated a 40% reduction in greenhouse gas emissions by 2030. IMO has not, however, mandated a specific technology but just set a target. Norsepower claims that rotor sails improve efficiency by up to 10% in ideal conditions. Even if rotorsails did this 24/7, it falls far short of the IMO mandated reduction. A switch to LNG reduces emissions by 20-25%. A switch to Ammonia or Nuclear reduces emissions by 100%.

[Spacewolf]

Interesting video, but he's wrong on a couple of points.

First, Charterers/Operators DO care about fuel efficiency enough that it effects which ship they hire. A ship with a 10% better fuel efficiency is going to get hired before another, less efficient one because fuel is one of the biggest cost for operators.

Second, He says until "the only way a rule will stick is if it's made internationally through the UN" and says there is no reason for ship owners to change. This shows some serious ignorance of the way international shipping is regulated and the current state of those regulations. Internationally, ships are regulated through the International Maritime Organization or IMO, not the UN. IMO has 175 member nations including every flag of convenience and every world economic power. IMO has mandated a 40% reduction in greenhouse gas emissions by 2030. IMO has not, however, mandated a specific technology but just set a target. Norsepower claims that rotor sails improve efficiency by up to 10% in ideal conditions. Even if rotorsails did this 24/7, it falls far short of the IMO mandated reduction. A switch to LNG reduces emissions by 20-25%. A switch to Ammonia or Nuclear reduces emissions by 100%.

I mean the IMO is part of the UN so it reads fine to me.
Having worked on ships that just transport Nuclear material the amount of issues we had with countries just not wanting us to go in their waters, not being allowed to use the two big Canals while we had material onboard and requirements for security I don't see any chance of ships using nuclear.

[Rockphed]

I mean the IMO is part of the UN so it reads fine to me.
Having worked on ships that just transport Nuclear material the amount of issues we had with countries just not wanting us to go in their waters, not being allowed to use the two big Canals while we had material onboard and requirements for security I don't see any chance of ships using nuclear.

People are afraid of nuclear power. I would say irrationally, but there are good reasons to be afraid (Chernobyl and fukushima one to mind). Considering what environmental havoc ships wreak with their bilges, I don't think restricting the availability of nuclear powered cargo ships is unwise. I wish it were else, but human nature is very hard to change.