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There are lots of experiments and even production ships with sails these days. Google for "sails on container ships" for lots of nice pictures and articles. T
by willvarfar 7y ago
There are lots of experiments and even production ships with sails these days. Google for "sails on container ships" for lots of nice pictures and articles.
The sails don't look like historic sails - they are often rotors that look like cylinders.
Maersk's Pelican, for example, is supposed to get 10% from its rotor sails.
Tangent: why do wind turbines look so conventional, with their propellers? There is a lot online about vertical axis wind turbines etc, but I've never seen one.
- joaomacp 7y agoArticle from 2015: https://www.wired.com/2015/05/future-wind-turbines-no-blades https://www.wired.com/2015/05/future-wind-turbines-no-blades I guess they're still not feasible for some reason.
- TaylorAlexander 7y agoI forget the details but vertical axis wind turbines are always less efficient than horizontal axis turbines. Off the top of my head I can't recall if the reason is that vertical axis turbines always have half of the rotor turning against the wind, but there is a basic reason I believe can be found on wikipedia.
- willvarfar 7y agohttps://en.wikipedia.org/wiki/Vertical_axis_wind_turbine https://en.wikipedia.org/wiki/Vertical_axis_wind_turbine says > research at Caltech has also shown that a carefully designed wind farm using VAWTs can have an output power ten times that of a HAWT wind farm of the same size etc The cups on the normal wind speed sensor have less drag into the wind. It would be easy to imagine a VAWT where a computer knew the wind direction and feathered the blades on the back sweep etc?
- TaylorAlexander 7y agoInteresting. I think I was wrong that the disadvantages I had seen before were easily found on Wikipedia. But I do see this quora post with bad things to say about VAWTs: https://www.quora.com/What-are-the-pros-and-cons-of-vertical-axis-wind-turbines https://www.quora.com/What-are-the-pros-and-cons-of-vertical...
- bilbo0s 7y agoThe problem is exhaust and the waste pollutants in it. If you switch to sails for a 10% improvement, wouldn't that mean you are still producing 90% of the waste pollutants and pumping it into the environment?
- r00fus 7y ago> Tangent: why do wind turbines look so conventional, with their propellers? There is a lot online about vertical axis wind turbines etc, but I've never seen one. Not sure if they still exist but east of SF on 580 (Altamonte pass?) I think there are still some.
- scrumbledober 7y agoI don't think there are any left that are visible from the freeway. I remember them being touted as a newer more efficient design, I wonder why they have been replaced by more traditional designs?