Of course this is an armchair thought experiment, but I am curious about your opinions.
"There’s a structural problem slowing down the process: ship owners (who have to make the investment) often don’t pay for the fuel – that’s the charterer’s duty. The charterer on the other side doesn’t charter the ship for long enough a period to make low-carbon technologies pay back"
I know bugger all about shipping but this doesn't seem logical. Wouldn't the person hiring said boat look at the estimated fuel cost as part of their cost/quote? If they know a ship has this or other effeciency features it should become part of their pricing comparison to alternate ships.
Additionally if the ship owner was also the operator, they could benefit from some vertical integration, training their crew on the new technology.
If the effect of the kites on prices becomes large enough or the technology becomes standard, expect widespread adoption, but it's a reasonable claim that the existing market structure slows rollout when it's only marginally profitable.
Is that a fair companrison? An owner occupier will often over capitalise because they desire something or have a lifestyle benifit beyond money. A rental owner wil look at dollars in/out. With the ships, its all coming down to a spreadsheet of cost vs benifit for both owner and hirer.
Whats needed is for regulation to come in and say 'ships that have these systems pay less to dock in port' or whatever. But, the technology has to be proven to reduce costs and carbon footprint - so someone needs to make an investment to prove this works before governments will get behind it.
Best is the enemy of good, and perfect is the enemy of possible.
If shell owned and operated their own boats, maybe, but I haven't seen that.
2 megawatts. Tremendous amount of force.
That or always make it so valuable to always strip the power unit to use again.
How proliferation of fissionable U-233 is different from proliferation of fissionable Pu-239? Both share ability to be separated from fuel without enrichment factories, both can be used to build a bomb.
I like thorium cycle, but proliferation should not be used as argument for it.
Im imagining something similar to when you'r flying a kite and begin to reign it in - it seems like it pulls you towards it.
Speed of airflow is approximately constant. Extreme case is reeling it in at 1mph in a 200mph wind. Force is approximately fixed.
Consider that I have an object with a fixed force on it (a good approximation in that case). If I reel it in, I do work equal to force times distance. That work goes into heating up the air. The force on my boat is the same.
I'm not sure it's a problem we care about, but you know how we solve the problem? Collapse (or partially collapse) the kite before reeling it in.
Your wind figure is crazy large by a factor of 10. Nevertheless, my point wasn't on the magnitude of extra energy produced through apparent wind, it was referring to the fact that apparent will in general produce more apparent.
Yes, you do get pulled forward a little bit more, but you can reel in the kite with arbitrarily little "pulled forward a little bit more" (by pulling in slowly) or arbitrarily much (by jerking hard).
The force on me and on the kite is equal-and-opposite, but it was equal before I started reeling it in too.
Yeah, of course. The force is always equal when objects aren't accelerating, so when you reel in the kite at a constant speed with an increased force, the force on your ship is increased as well. When you reel in with more force you reel in faster, which means that you can make your increase in force arbitrarily small, but in doing so you'll make you're increase in speed arbitrarily small and make your reeling time arbitrarily large. In doing so, you'll end up accelerating the ship by the same amount.
The work done in reeling in the kite is obviously larger than the kinetic energy imparted on the ship and is minimised by reeling in the kite arbitrarily slowly. That energy doesn't just go into fluid interactions but also the potential energy of having your foil back at the ship as well as the ship's kinetic energy.
All of that is a bit of window dressing. To reel in your kite you need to increase the pull or force on its lines. That increase will equivalently act on the ship. The ship is being pulled a little bit stronger in the retraction process just like the original commenter asked.
You basically let the kite fall, then use its pull to generate energy and make it soar, then let it fall again..
If the wind speed isn't constant then you could save power by only reeling the kite in when the wind slacks off. If you felt especially proactive you could generate power by reeling it out during gusts then back in during lulls.