“Hydrogen” sounds “scientific”. But as with “global warming” it heads toward “single factor analysis”. It allows everyone to feel like “a scientist”, by just understanding a single fact from 3rd Grade elementary school. Your first chemical formula! 2 H + O = H2O !!So now that we’re all geniuses for paying attention in 3rd Grade, how much emery out do you get per unit energy in? I remember a study using a wind turbine like we have here, and after all the losses from making the electricity, to electrolyzing water, to compressing it, to running a fuel cell to get electricity back, I think their return was about 5%.
OK but let’s say you do a way better job and get back 25%.
How would you feel if you charged your phone to 100-%, then unplugged the super-expensive charger, and suddenly it said “low battery - only 25% charge left.”?
In the event of hydrogen production by OCEANERGY, the conversion stages would certainly include the production of electricity then hydrogen by electrolysis, but that is all, hydrogen being used as fuel for the jet engine, not to produce electricity.
In absolute terms there are two operating modes which are described on
A hydrogen-powered aircraft is an aeroplane that uses hydrogen fuel as a power source. Hydrogen can either be burned in a jet engine or another kind of internal combustion engine, or can be used to power a fuel cell to generate electricity to power a propeller.
So things are a bit more nuanced than what is asserted above.
Mark Jacobson, the author of the post on LinkedIn I quoted previously, has a number of scientific publications to his credit and supports the development of hydrogen as a sustainable alternative. Other scientists have the opposite opinion. All are experts in their field.
Not being a specialist in this field, I have no opinion. However, I am surprised to see the know-it-alls asserting categorical opinions on many subjects, such as energy (in this case hydrogen) or global warming, ridiculing the debate to a primary school affair when they have not published anything scientific in these fields, simply repeating what they have heard here and there, retaining only what suits their comfort.
OK well, Pierre, that is a different case than a fuel cell at 50% efficiency. You’ve got an IC Or jet engine at maybe 30% efficiency. And you’ve got to compress or liquefy the hydrogen, so you’re getting about 15 - 20% of the energy back, whereas just using the electricity you get back close to 100% of it “back”. So is hydrogen a good use of that electricity? You have a plane with little room left for cargo or passengers, who must share the space with the fuel tanks. Also, I seem to remember hydrogen is a very weak fuel when burned in an internal combustion engine. Like worse than natural gas. Not sure on that, but in general, you cannot find a less efficient means of energy storage than hydrogen. It’s just the facts. Not an opinion. And how dare I speak simple truths in the face of an onslaught of BS? Somebody’s gotta do it. I have scientific training, so my opinion is as good as anybody else’s.
I outguessed the experts regarding what the James Webb space telescope was going to see. They expected new, small, young galaxies in a newly- emerged baby universe, right after the Big Bang! Like kids repeating a bible story. I said no, you’re gonna find more of the same as what we see now, more fully developed galaxies, just as always happens when we get a better telescope. Not that hard to figure out. Rather than studying what someone tells you is “the science” study the scientists themselves and how they always make the same mistakes.
Here’s why I think Oceanergy is not a viable idea:
- we do not see kites able to pull ships. They “target” 10–15% of power to pull the ship thru the water. So we’re already an order of magnitude less than needed to pull a ship.
But now we add the underwater turbines which will cause reverse thrust, further slowing the ship. So where does that leave us? Two (2) orders of magnitude too weak to do the job?
Plus all the inefficiencies of hydrogen?
Here’s what “Oceanergy” really is: it’s like Magen: a sexy-sounding dream, sold to the gullible masses by making its story too complicated for most people to analyze. - even if the kite-ship WERE efficient, compare to a regular wind turbine:
Are we pretending an operating ship is cheaper than a tower? Hmmm…
Are we pretending dragging a heavy ship hull through the ocean is more efficient than ball bearings? Hmmmm…
And as far as using hydrogen to make steel, hydrocarbons and steel go together like a happy husband and wife. Hydrocarbons provide a carbon rich environment which is a natural fit for making steel. Buy steel and it is coated with oil for rust protection. Make a machine and it will be lubricated with hydrocarbons. Then steel is used to obtain the hydrocarbons. Meanwhile, people keep talking about making steel with hydrogen, but that would be inappropriate cuz hydrogen offers no carbon, and is a terrible waste of energy.
Oceanergy seeks to place your mind into an all-accepting trance: starting with cleverly combining “ocean” and “energy” so you already think they must be clever, the story of how the energy of a kite will be converted to fuel, or steel production is so complicated most people won’t follow it and “just believe”. Meanwhile the story is so full of holes it is a complete non-starter of an idea, starting with the lack of sufficient power To pull a ship with generators, to the final product envisioned. Under the right circumstances, otherwise clear-thinking people will fall for almost anything! 
There are many things being said here and there making it hard to give sensible replies. But I would like to mention, also as someone not expert in the field, that airplane fuel is also about realistic renewable options as well as fuel economy. Because right now there are few good options to replace aircraft fuel. So if those were banned, one would expect airlines to pay a lot more for a working fuel. Even if producing it required a lot of energy.
Yes Tallak, there are few options to replace aviation fuel. Why? Because with aviation, you can’t fake it anymore. Light weight and efficiency, not to mention safety and affordability, all have to come together for success. Turns out there is a great way to use hydrogen as fuel: arrange the hydrogen atoms on a backbone of carbon atoms, Almost like a super turbine of fuels, and you have a natural liquid high energy fuel requiring no compression, no ultra-high-pressure storage tanks, no gigantic fuel tanks taking up the Volume of the fuselage, no onboard cryogenic liquefaction system. Just fuel tanks and fuel pumps. Pour it in by gravity. Almost like a miracle - and half of your fuel is already in the air (oxygen) - another miracle gift from Mother Nature. Making such hydrocarbon fuels from scratch is possible. More likely fossil fuels will still be used, because it would be inefficient and probably a wasteful use of renewable energy to make the fuel from scratch, although various biodiesel type options are already in use. I have a friend who would pump out restaurant grease tanks and make biodiesel to run his pickup truck.
OK, back to the impossibility of Oceanergy: one obvious wasteful step I did not mention is:
Do you think using a kite to drag a water turbine through a ship’s wake to generate electricity is more efficient than using a wind turbine rotor to spin a generator directly? Not very likely. In fact, I’d surmise you might lose MOST of your kite energy in that step alone.
Bottom line is if anyone should be able to debunk Oceanergy, it should be this crowd in particular. For example, most people might tend to believe a kite could not only provide 100% of the power required to pull a ship, but let’s call it 200% of that amount, since the mere pulling of the ship accomplished nothing, except to Bring the ship up to “even” or a “neutral“ state where there is Then still vastly more reserve power from that same kite - enough extra power available to pull underwater turbines, with their natural reverse thrust. And the average schmoe out there could perhaps be forgiven for swallowing their story hook, line, and sinker, due to not knowing anything about previous cumulative experience using kites to pull ships. But not this crowd. We’ve witnessed the decade-long+ agony of companies like Skysails trying to even help pull a ship, maybe hoping for a 10 - 15% assist, then finally giving up and selling that main part of the company off to someone else who hopes to make the concept work. Given that, it seems to me everyone in this group should have immediately flagged Oceanergy as a non-starter.
I think the use of large flexible kites is in line with the evolution of AWE (kite-surfing, kite boats, kite ships). In the open sea the conversion by a hydro turbine makes sense, for a continuous production, not to have the generator in flight.
Incidentally SkySails remains a leader in prototyping ship towing with kites, not to mention the average 92 kW achieved with a reeling (yo-yo) flexible kite, by far the greatest performance in AWE. If SkySails is agonizing, I’m afraid the other AWE players are living dead.
Where things get complicated is in the way the tasks are divided up. I could see numerous systems like this dragging a hydro turbine, recharging batteries (for hydrogen, things are more complex). Then these batteries would be collected in a platform like an oil platform. Ships would come from all directions to take away the recharged batteries while leaving batteries to be recharged.
This never took off in cars. To do it offshore would be very complex involving heave compensated cranes and such. It seems to me such an expensive way that it is not very interesting. This is why I favored in transit charging. Or maybe some weird technology like liquid batteries (diesel? 
)
There is a difference in trying to pull a big cargo ship and a much smaller power generation ship. There is multiple kite powered small boats out there with 100% of their energy coming from the kite. For example the Kiteboat Project of Don Montague.
Yep, when having kite-kayaked - I’ve often wondered … How the hell are we going to stop?.. I can confirm - a wee craft power requirement is different to that of a big tanker.
As for battery charging offshore check out the NZTC page on Verlume
Battery deployments underwater on the seabed for Northsea infrastructure… Collaborative wave power project aims to decarbonise subsea operations - Net Zero Technology Centre
They’re also developing quick connect standards
Nobody ever said you can’t pull a rowboat or a kayak using a kite. Is dragging a ship around by windpower, with that ship then dragging water turbines around to create electricity, more efficient than just using a wind turbine to generate electricity?
I think I’m wasting my breath here even questioning or analyzing the logic of anything. I should just wish all the true-believers happy dreams! 
Performance data in the description.
As the first luxury yacht manufacturer, we are now combining the power of the sun as well as the wind to provide an even more eco-friendly cruising experience.
Here you see our SILENT 60 #1 equipped with a 9m2 kite system.
When testing the 9m2 kite at wind angles of up to 40 degrees, with the engines turned off and no propellers turning, the SILENT 60 effortlessly reached speeds between 4 and 5 knots. Under the same conditions, when switching on the electric motors to draw just 1kW each to reduce drag from the propellers and improve the flow of water over the rudders for better steering, speeds could be increased to almost 7 knots.
A big advantage of a kite compared to a conventional sail is, that the kite flies at much higher altitudes where winds are far stronger.
In addition, there is no need of a tall and heavy mast with a complex rigging system. The kite including its electrical winch, as well as its short and collapsible mast can be easily stored in a dedicated locker under a hatch on the foredeck for whenever it is not in use.
It looks like OCEANERGY in small.
And a 9 meter kite is tiny. I use a 12 meter kite like 70-80% of the times i go kitesurfing or snowkiting because the 9 meter is to small to get the power i want in the winds i mostly get where i live. And that is just for pulling a 80 kg person…
Some news about hydrogen storage:
The team made up of Patricia de Rango, Daniel Fruchart, Albin Chaise, Michel Jehan and Nataliya Skryabina has won the European Patent Office’s 2023 European Inventor Award in the ‘Research’ category.
A video showing how this storage process works:
At 1:04: “How it works? When metal is subject to high pressure, it absorbs hydrogen like a sponge.”
At 1:04:52: “…when we began to works with the 30 cm discs, which each contained over 600 grams of hydrogen…”.
It looks to be a very significant step compared to the state of the art as mentioned below.
https://energies.airliquide.com/resources-planet-hydrogen/how-hydrogen-stored
In the solid form
The storage of hydrogen in solid form, i.e. stored in another material, is also a promising avenue of research.
Methods for storing hydrogen in solid form are techniques involving absorption or adsorption mechanisms of hydrogen by a material.
One example is to form solid metallic hydrides through the reaction of hydrogen with certain metal alloys. This absorption is the result of the reversible chemical combination of hydrogen with the atoms that comprise these materials. The most promising materials are composed of magnesium and alanates.
Only a low mass of hydrogen can be stored in these materials, which is currently the major downside of this technology. In fact, the best materials currently generate a ratio of hydrogen weight to the total weight of the tank of not more than 2 to 3%.
Before considering large-scale applications, it is also important to master certain key parameters such as kinetics (cell performance), and the temperature and pressure of the charge and discharge cycles of hydrogen in these materials.
My feeling is that manufacturing, storing, transporting, and delivering is a lot, and probably too much.
I would rather see (to stay in the field of water) fixed floating factories manufacturing, storing, and delivering, on site. Perhaps to supply ships.
I guess it is comforting to “change the subject” to possible approaches toward the lowest efficiency method of energy storage commonly cited, hydrogen. Meanwhile, anything going on in AWE yet? Yeah, didn’t think so. Talking about hydrogen is not going to save you.
Hi Doug,
The inventors were thinking more of hydrogen produced in nuclear power plants, and stored and delivered on site.
It allows you to talk about something.
Hello Pierre: Thanks for clarifying. As I recall, Germany was shutting down baseline spinning-reserve nuke plants and substituting intermittent wind turbines. The idea was “nukes are bad”, while “wind is good”. The result was some of the most expensive electricity in the world. Nuke plants are great, as long as you can guarantee that, going into the future, the materials don’t fall into the wrong hands. I wish some of these people could make up their mind what is the best, or even an acceptable, form of energy. I have no problem with using the extra power and heat from a nuke plant to produce industrial hydrogen, but you have to admit, it has nothing to do with wind energy, nothing to do with AWE, and I remember a time when such a post might have been rejected as “off-topic”. But it seems there is just not much left to say about AWE, except that such a scenario would probably make Oceanergy irrelevant, as though one more “press-release breakthrough” needs any help failing and ultimately disappearing.