Then again, Peter Lynn’s analysis had a lot to offer as far as stepping back to see the big picture: By the turn of the 20th century, sail had already been obsolete due to steam power, then diesel-type engines made steam obsolete. OK so we’re already multiple steps beyond direct wind power for boats. Then he adds the business-case, taking into account the value of time, and ability to reliably follow a schedule and deliver in less time, and it veers toward a factor affecting regular wind energy too - the intermittency of wind requires redundancy of a fossil-fuel backup, which adds cost. Economics and reliability push one into looking at the cost of a system and not wanting to spend duplicate money on two systems, to where maybe the cost of fuel is not the overwhelming deciding factor out of all the expenses and revenue the business, say an inter-island delivery service, must factor in, to best serve the needs of its customers. I guess one must find a case where kite-pulling can be sensibly incorporated into a business model, then survive as an economically-sensible practice.
A 5,000 km containership would require approximately 6.5 GWh of LFP batteries.
The average cost of lithium-ion batteries has plummeted 89% since 2010, and is expected to reach $50 per kWh in the near future. Assuming a battery cost of $100 per kWh, the TCP for a battery-electric containership is already lower than that of an ICE equivalent, for routes less than 1,000km. And when battery prices reach $50 per kWh, which is predicted for the near future, electrified ships will be cost-effective on routes as long as 5,000km.
…and with in-transit charging even longer range. Plan B must be alternative energy sources or extra charging stops.
That number seems very high. Maybe even wrong…
OK so I’m scanning for how to place this into “the proper” topic. So I’m looking for the topic of wind-powered ships - didn’t find it, so I placed it in “news”. I’m guessing it will probably end up being “moved” to “slow chat”. Seems like the bottom line is, on any given day, there just isn’t much to say about “airborne wind energy” anyway. I mean, where are we at, two years into “systems being sold and shipped” with not a word on how any of them are working? Makes no sense. It’s like a pretend “industry” that doesn’t really exist except in our imaginations. Whatever.
I just ran across (sigh)… a couple of articles… in a marine/shipping publication… one basically a press-release by a company promoting their own vested interest, telling us how wind power for shipping will be forced into existence even if it doesn’t really help much, due to desperate attempts to comply with some new ratings system that sounds like it gives extra points for symbolic “compliance”, even if it just costs more, adds more weight and complexity, and reduces cargo capacity (even though they try to say it doesn’t) including flettner-type spinning sails, regular sails (one from China even looks like the old square-rigger sails of old). Oh yeah - I almost forgot - they also include the possibility of kites…
LINKS:
I think you’ve cracked it @dougselsam
Your posts move much more predictably than these ships
We just need to tether your posts
Here’s another one - an oil supertanker from China with 4 square-rigger sails:
Claims a 9.8% fuel savings.
Should we assume they doubled the real savings? Or don’t they really know yet? The fossil fuel industry trying to “decarbonize” always seems ironic. I think if it works well they should do it just for the sake of efficiency - to save fuel. Someone could be the biggest fan of fossil fuels and still be in favor of saving fuel use when possible. 
Ooops - “edit” here: It says “whose four large sails will cut down average fuel consumption by nearly 10%.”
OK so that is just projected fuel savings. Remember, with this stuff, all news must remain perpetually “in the future”…
OK Guys, here’s another one (more news of the future), this time using kites. The shipping company is called K-lines. But the K stands for Kawasaki…
LINK:
I like wind powered tugs, with electric power backup, or maybe ammonia backup or something.
You don’t have the obstructions on the deck other solutions might have; you don’t have to retrofit each ship and can use it on more than one ship; you don’t have to think about how to build and finance a giant ship from scratch; you can charge it at your relative leisure at port and possibly at charge stations during transport; you can connect multiple tugs to a single ship; you can let another tug take over when the batteries are empty; you can sail it back to shore when the batteries are empty and you had a headwind going out; you can station it at sea, possibly charging, waiting for ships; you have a clear value proposition your customer can buy into on a per journey basis; you can change home ports based on prevailing winds or available electric capacity; you can retrofit improvements to your design more quickly and easily to the tugs; it’s not permanently attached to the ship so it won’t slow it down when there are headwinds or the batteries are empty; you can retrofit existing tugs/ships; you can license your design and franchise your business model, for example.
Peter Lynn about Kite Power for Commercial Shipping:
There are things that kites can do superbly- recreational kite sailing, kite boarding, buggying, sports kite flying, snow kiting, possibly kite energy systems and so on- more than enough for a kite industry many times its current size, but powering commercial shipping is not one of them.
I have this idea to separate the kites from the mother ship. If we have a number of tugboats powered by the wind, pulling the mother ship, then we can greatly increase the pulling force. These tugboats can be spread out over a large area and can even be remotely controlled.
This is for me something completely new and seems feasible in terms of giving some added power compared to something mounted on deck. The complexity though, seems high
Perhaps just a single tugboat might make sense? That way you might be able improve the utilization factor of the kite. One could focus on stretches of water that would be mostly crosswind with reasonable wind speeds.
I was thinking the same as a conceptual starting point. A variable length wire could be used with virtually lossless electric winching. The satellite vessel could move in a different direction and tug itself back with support from the main vessel. It could move faster and in a different direction, in cycles.
All these things being said, this is interesting but I rather prefer the more KISS approach of a single vessel with the kites mounted on deck.
My approach to achieving much the same effects is to make the kite generate electricity and propulsion, so that the kites always operate at the best efficiency
The advantage of multiple tugs is that they can be spaced far apart so that kites can operate independently without interference. We can use larger kites but we are limited in size due to difficulties in launching and landing.
In the open sea the tugs could perhaps be replaced with Syroco devices for records, in order to eliminate most of the hydrodynamic drag and the mass and volume of the multiple tugs, the respective flying floats being only used to store then launch their respective kites.
The deployment would be in two stages: the Syroco devices, contained in compartments of the ship, are ejected; then the kites take flight, first towing the devices to their respective locations before towing the whole.
That said I think using only one ship and increasing both kite area and tether length is simpler.
Besides that, see also THE KITESHIP™ PROJECT -CHAPTER 5 IN THE CONTINUING SAGA alone or in combination with the previous.
Dave Culp
Ron SwensonA video:
Also produced electricity could lead to make e-fuels (Electrofuel - Wikipedia).
Here’s another angle on kites pulling ships:
Previously I had said it seemed suspicious that they always choose a kite of a small enough size that it can only be expected to slightly reduce fuel usage.
Here’s a slightly different angle:
Rather than choosing a large ship, that is then said to slightly reduce fuel use due to a kite, why don’t they choose a ship of a smaller size, so it can be pulled 100% by the kite when winds are right?
Probably because they are looking for a business opportunity rather than doing a vanity project. Dont get me wrong though, both kinds have their place. Some prefer one or the other