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Comments · 17

  1. Re:Climate change... by ShanghaiBill · · Score: 1 · on Engineering Firm Plans To Tow Icebergs From Antarctica To Parched Dubai (stuff.co.nz)

    Disruption of the natural flow of hot & cold currents much?

    Disruption of currents would be utterly negligible.

    A far greater concern is the CO2 emissions from the fuel used by the tugboats.

    They should use Skysails to tow the berg with wind power.

  2. Re:And low-emission transport trucks, too by Neil+Boekend · · Score: 1 · on To Really Cut Emissions, We Need Electric Buses, Not Just Electric Cars

    The current ones are quite different from ye olde frigates

  3. Re:Still a ways to go by Neil+Boekend · · Score: 1 · on Sulfur Polymers Could Enable Long-Lasting, High-Capacity Batteries

    700 kg of fuel equals about an hour of usage. However, if the ship is all electric one can assume a 3x as efficient powertrain, so 3 hours. If we combine the solar panels with a skysail which provides around 2000 kW continuously we would get an additional 48 MWh or 172,800 MJ (depending on shipping routes). This equals to approx 4000 kg/day without efficiency improvements or 5.7 hours. With a powertrain efficiency improvement of a factor 3 (doable when using electric power) this would equal to 17 hours of boating.
    With the 3 hours of solar boating we'd have 20 hours a day of clean shipping. Since required power is approximately related to speed squared, having a bit lower speed would offer a lot less fuel usage. Low speed is already a disadvantage, but with moder consumer wishes a "Sustainable inter continental shipping" logo splashed everywhere would probably increase sales for your customers. Maybe DHL could advertise long delivery time green shipping thing.

    To get back on topic: Batteries. Large container ships are meant for long distances, so we can assume the ship will be on the ocean for months at a time.
    If I assume lithium sulfur batteries have a voltage of 3.5 V (from Li-Ion batteries) I assume 3.5 Wh/g or 12,600J. We need about 30,100,000,000J/day so that's 2,388,888 g or 2.4 metric tons. To go 3 months you'd need 223.2 metric tons of these new batteries.
    Container ships are big, in the order of 50.000 metric tons so it would be possible. However the price of these batteries isn't known yet and it may just be more expensive than a skysail and a deck of solar panels.

    With this back of the envelope calculations I think now that the solution would be in the category of SkySail + solar panels + batteries. Cruise on SkySail + batteries and top the batteries off with the solar panels if you can.
    As for the corrosive environment: Glass doesn't corrode and the rest can be covered in plastic which doesn't corrode either. They should be fully sealed of course so there are no metal parts in contact with the corrosive air.
    I just think the maintenance crews aren't going to like it much. It would require a lot of retraining.

    Note: I am an engineer. However I am not an experienced engineer in this field.

  4. Already exists by RobVB · · Score: 5, Insightful · on One Giant Cargo Ship Pollutes As Much As 50M Cars

    This has been developed and put into use by a German company: SkySails. They report fuel savings of up to 30% in some conditions.

    And yes, cutting speeds by about 10% reduces fuel use for the same distance by about 20%. This happens all the time in economy dips. Since fuel is the largest cost in shipping and its share in total costs keeps rising, it's an easy way to save a lot of money by offering up a little time. Maersk, the big container line, has reduced the operating speed on its ships from 22 to 20 knots because of the global economic recession. This is a pretty hard thing to do for them, because their ships operate on a schedule and have to stick to it, so changing operating speed means changing the schedule worldwide.

    In other types of shipping such as bulk carriers and tankers, this practice is much more common. When there is little demand, ships can go slower to save money so they make more profit per job. When the economy is doing well and demand is high, shipping prices can suddenly skyrocket. In this case, sailing a little faster is the best way to transport more cargo in the same time, and thus complete more jobs. In fact, increasing speed is the short-term version of building new ships: it virtually creates more carrying capacity instantly. Building a ship takes months or years, so it can't be used to respond to sudden changes in demand.

  5. Re:set sail by Noughmad · · Score: 1 · on Alaska To Export Billions of Gallons of Water

    I still don't understand why any ship company would not want to have things like these installed. Is it because most of them carry oil?

  6. Sky Sails work similarly by RobVB · · Score: 1 · on Underwater Ocean Kites To Harvest Tidal Energy

    That's the same system Sky Sails use (video). The kite makes, among other manoeuvres, figure 8 loops, and reaches speeds of up to 180 knots (180 nautical miles an hour, 207 mph, 333 kmph) in winds of 3 to 8 Beaufort (10 to 40 knots). It's actually a very similar design, that's also doing its part in reducing fossil fuel consumption.

    I hope they manage to balance construction and maintenance costs with profits. It sounds promising, but then so do a lot of things.

  7. Re:We're doing it wrong by kryten_nl · · Score: 4, Insightful · on Kite-Powered Ship Launched
    Why you responded to my post, is beyond me. You certainly make a valid point, but you are using the wrong system boundaries. You're right that kites and the small horse used for the acceleration of sports cars (proposed below) do not solve the worlds problems. Indeed a paradigm shift is needed in order to fully solve our long term problems. We do not need to make transportation cheaper, we need to reduce transportation altogether.

    Developing technologies that save the shipping company $1600/day is a waste of time and effort. You fail to notice that the effort concerned with developing and marketing such a kite are not interchangeable with the efforts to find clean and reusable local power generation methods. Do you really think that the founders of the company in question (SkySails GmbH.), could have contributed anything on the scale you are suggesting? The funding they received from local and European governments might be contributed to the uses you describe, but in comparison with fusion research it would still be a drop on a hot plate. SkySails was funded for 10% by public institutions (related to governments in one way or another) of which the EU contributed EUR 1.200.000. I'll leave the comparison with fusion research up to your friend Google.
  8. Re:Reinventing the wheel, and getting $$$ for it by Asic+Eng · · Score: 1 · on Football Field-Sized Kite Powers Latest Freighter

    There is a lot of technical info (including where they attach the kite) available here: http://www.skysails.info/fileadmin/user_upload/Pressedownload/Dokumente/SkySailsTechnologie_en.pdf One particularly interesting point is that they include a system which helps you plan the optimal route according to the weather forecast.

  9. Re:size of a football field ... by linoleo · · Score: 1 · on Football Field-Sized Kite Powers Latest Freighter

    BTW, the current kite on the Beluga Skysails is 160 m^2, about 10x the size of a large kitesurfing kite but only 2/3 the size of a tennis court. This size will ultimately be used on superyachts and fishing boats; for tankers and container ships Skysails is following an engineering roadmap that doubles kite area every year or so. With current technology they expect to max out at 2500-5000 m^2, which is indeed near the size of a football (as in: soccer) field, hence the confusion.

    I recommend the SkySails website for lots of good information. Disclaimer: I have 50 kiloeuros riding on these guys.

  10. Link to video... by rHBa · · Score: 3, Informative · on Football Field-Sized Kite Powers Latest Freighter

    Thought this might interest those who didn't RTFA (or didn't have time to trawl through the website looking for it):

    http://www.skysails.info/index.php?id=71&L=1

  11. Re:Size of a Football field? by RedWizzard · · Score: 1 · on Football Field-Sized Kite Powers Latest Freighter

    The test sail, if you drill down, is 160 sq. m.

    Hardly the size of a football field.

    The homepage says that kites with areas up to 320 sq m will be available in 2007. Given that 2007 is almost over I'd say the homepage is a little out of date. According to this page SkySails for cargo ships range between 160 and 5000 sq m. It's not unreasonable to describe 5000 sq m as football field-sized.
  12. Re:30-50% is more like it by florescent_beige · · Score: 2, Interesting · on Football Field-Sized Kite Powers Latest Freighter

    I just watched their promo video at SkySails. (The video is here). They can point as close as 50 degrees off the wind, so tacking is possible. In other words, if oil went up to $1000 a barrel they could theoretically sail either way across the Atlantic, albeit taking 2 or 3 times as long.

    They show 30% fuel savings, but oil prices have gone up a lot recently, so it might well be closer to 50% now. It launches and recovers automatically and has an automatic control system.

  13. Re:no other technique??? by ductonius · · Score: 2, Insightful · on Future Ships Could Float On Bubbles
    Except sails.

    That wouldn't be saving energy, that would be collecting it from an ubiquitous source. A sailing ship equipped with systems this research develops would outperform one without them.

    Somehow using wind to suppliment conventional fuels is a good idea though. Why pay for what you can get for free?
    clicky --> http://www.skysails.info/
  14. For hundreds of years ships crossed w/o fuel..... by bodland · · Score: 1 · on Solar Boat To Cross the Atlantic

    Sail. It makes so much sence to incorporate sail technology back into shipping. Wind after all is free. The only reason sail was abandoned was because diesel became so cheap, ships faster and larger that sail became too costly.

    ...sail's last hurrah...

    1949 - "316-foot, four-masted square-rigger Pamir on the last voyage around Cape Horn by a freight-carrying sailing ship, a passage from Australia to England that marked the end of the Great Age of Sail."

    http://www.sailingmagazine.net/fullby0104.html

    Seems someone has the idea...of using wind to aid ship propulsion.

    http://www.msnbc.msn.com/id/13325827/site/newsweek /
    http://www.skysails.info/

  15. Re:How big? by Cromac · · Score: 4, Informative · on Wind Powered Freighters Return
    At this site http://www.bath.ac.uk/~ccsshb/12cyl/ the most powerful ship diesel running at its most efficient speed burns 1,660 gallons of heavy fuel oil per hour. Even using the cheap, nasty fuel these ships burn that's a big expense.

    According to http://www.skysails.info/index.php?id=66&L=1

    Increasing efficiency using ship diesel has almost reached its maximum potential and is also extremely expensive. According to the calculation of an expert on ship propulsions, shipping companies would have to invest up to 500,000 Euros in order to reduce a ship's fuel consumption by 1%. Fuel savings of 5% would be a fantastic performance for ship owners, according to Niels Stolberg, managing partner of Bremen-based shipping company Beluga Shipping GmbH.
    To get an increase of 35% (the max claimed by SkySails) would mean a 3.5 million euro investment, that's a lot of crewman salaries even at union wages and less than the Skysails implementation would cost.

    They have some interesting performance calculations on their website too about how much sail produces how much energy. http://www.skysails.info/index.php?id=89&L=1

  16. Re:How big? by Cromac · · Score: 4, Informative · on Wind Powered Freighters Return
    At this site http://www.bath.ac.uk/~ccsshb/12cyl/ the most powerful ship diesel running at its most efficient speed burns 1,660 gallons of heavy fuel oil per hour. Even using the cheap, nasty fuel these ships burn that's a big expense.

    According to http://www.skysails.info/index.php?id=66&L=1

    Increasing efficiency using ship diesel has almost reached its maximum potential and is also extremely expensive. According to the calculation of an expert on ship propulsions, shipping companies would have to invest up to 500,000 Euros in order to reduce a ship's fuel consumption by 1%. Fuel savings of 5% would be a fantastic performance for ship owners, according to Niels Stolberg, managing partner of Bremen-based shipping company Beluga Shipping GmbH.
    To get an increase of 35% (the max claimed by SkySails) would mean a 3.5 million euro investment, that's a lot of crewman salaries even at union wages and less than the Skysails implementation would cost.

    They have some interesting performance calculations on their website too about how much sail produces how much energy. http://www.skysails.info/index.php?id=89&L=1

  17. I'm skeptical by Jeff+Molby · · Score: 3, Informative · on Wind Powered Freighters Return

    Here is a video from their site. This is obviously a prototype, so they have a LOT of scaling to do. Plus, the only time you see the boat (yes, I said boat, not ship) moving with any significant speed, you can't see the rear, so it's safe to assume that its engine is assisting.