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ISL
Wow. A 25% efficiency boost is huge, both for the shipping company and for the planet.

Wikipedia states that 3-4% of the global carbon footprint is shipping. https://en.wikipedia.org/wiki/Environmental_impact_of_shippi...

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zaroth
CO2 is cut by 27% through a combination of systems. I think the MALS (air bubble) tech on it's own increases fuel efficiency by ~10%, based on the published papers, and you spend 2% of that gain on actually producing the bubbles.

Apparently break-even on the upgrade cost is reached within a couple months. They are also starting to put it in cruise liners [1].

[1] - http://www.seatrade-insider.com/news/news-headlines/micro-bu...

hartror
This is great however I cannot help wondering if there will be any unintended consequences of extensive uptake of this technology. For example could this increase levels of O2/CO2/N2 dissolved in the worlds oceans upsetting the balance in an ecosystem? Even with the 20th century's long track record of unintended consequences this conversation still seems to be a rarity and when it happens is minimised by stakeholders.
ars
Air bubbles in the ocean being a problem? Not a chance.

Waves make trillions (10^12) of times as much bubbles. (Not exaggerating about the trillion BTW, I ran some quick Fermi estimations to come up with that number.)

zaroth 

  The micro-bubbles are generated by heating, then cooling,
  water to avoid releasing it as steam.
That sounds fairly benign. Can anyone explain the mechanism?
D_Alex
>will be any unintended consequences of extensive uptake of this technology. For example could this increase levels of O2/CO2/N2 dissolved in the worlds oceans...

No. There will be no measurable effect whatsoever. The waves on the ocean's surface do a fine job of aeration, and cover an area millions of times larger than the ships' surfaces.

quanticle
Interesting. I know Navy vessels do this [1] but in their case, the motivation is to trap machinery noise and reduce the sonar profile of the vessel.

[1] http://en.wikipedia.org/wiki/Prairie-Masker

zaroth
Articles say an 'unexpected benefit' is reduced prop noise. They did study the effect of bubbles on prop efficiency and apparently it is minimal, but noise is reduced significantly.