In conversation with Michael Köhler of Silent-Yachts | SuperYacht Times 

Nope never in time hybrid systems will take over as they make the most sense

@@BlackHawk-yl5gu it depends on the use case. Ship to shore are prime for direct battery/solar powered systems. As are houseboats - the fastest growing segment in NA boating. Smaller sailboats are also great candidates for solar electric systems. But long range and larger yachts are most likely best choice for hybrids.

Or the new 120

How does one get/transport the hydrogen in a way that’s more efficient than staying electric?

@@Huntred 'Green Hydrogen' can be produced and stored on site in any number of different ways.

​@@SoCalFreelance But can it be produced, transported, stored, and even used more efficiently than electricity? That I'm not sure about. Excerpt from "Electrify", by Saul Griffith: "Similarly people talk about producing hydrogen or synthetic fuels like ammonia or ethanol with properties similar to gasoline or natural gas. Again, it sounds easy but it requires using more renewably or nuclear-generated electricity to create the fuels than you would need to simplify power in an electric car [this section of the book focuses on automobile transportation but I imagine boats are functionally the same] straight from the grid. Hydrogen vehicles are the canonical case of this silliness. The idea is to make a unit of electricity, lost 25% of it in converting it to hydrogen, and lose another 25% of it in a fuel cell that converts it back into electricity that powers the wheels -- all for the convenience of having a familiar fuel to fill a familiar tank. Nearly all hydrogen now used in hydrogen vehicles is a byproduct of natural gas, which just perpetuates our current problem, and is part of the reason these fuels have been cynically over-promoted as a solution." That's pretty damning to me. However even if we take the natural gas pathway out and just use electricity - even from renewable sources -- the efficiency argument gets rekt. Continuing the passage. "The total efficiency of a total-energy pathway is the sum of the efficiencies of the component pathways. To illustrate the point, let's look at the three ways to power a car [again, this is pathway analysis, so boats are a reasonable swap]: via electricity, hydrogen, or some magical gasoline-like fuel produced from electricity (the latest entrant in this shell game is Prometheus Fuels, complete with advertising copy that makes you believe you can save the world with your old Ford Mustang). In an electric car, we take the electricity, store it in a battery (~90% efficient), and then pass that electricity through a drivetrain that is about (~80% efficient.) Total efficiency = 1 x 0.9 x 0.8 = 0.72. We get 0.72 units of transportation for one unit of electricity. If we use the same electricity to make hydrogen (via electrolysis, ~65% efficient), then compress it into a tank and decompress it back out (~75% efficient), then run it through a fuel cell (~50%): Total efficiency = 1 x 0.65 x 0.75 x 0.5 = 0.24 We only get 0.24 units of transportation for the same one unit of electricity." I won't bother including gasoline but the final result there is 0.1. Which seems to say that on a linear spectrum, hydrogen is much closer to gasoline (not sure how diesel compares, but I imagine on par) in terms of being inefficient (2.4x) than it is to electricity (3x). And that's before we factor in the hidden costs, like transportation (much more efficient to go by wire than drive hydrogen tanks around) and again, hoping one isn't using petroleum processing to get the hydrogen because then the "green" argument is gone as it requires the extraction and production of natural gas.. So given that, I just don't see how hydrogen is a practical, green, and efficient fuel source, especially for this use case where hydrogen stations would be needed "at every port" because even without truck (or worse, diesel ship-based!) transportation of hydrogen, one is basically gonna use *tons* of electricity to crack water by building micro electrolysis stations nearly at every port, where for every until of electricity required, at least 75% of that is wasted in the production process before it ever reaches the propeller.

right now Hydrogen storage is the issue, there's tech coming out now that will mitigate it but even most of those are impractical for yachts. I think by the time we get hydrogen down we'll have solar and battery tech that will render it obsolete... at least for this application. Cars I think it will be more viable, hydrogen hybrids will have an important place in the future. The problem is that the upcoming tech is either solid state (impractical for yachts) or liquid/gas storage (which has a habit of leaking out, making storage a safety hazard) I might be wrong since it's been about 2/3 years since I did my deep dive on upcoming hydrogen technologies.

@@KMCA779 The French hydrogen fuel cell ship Energy Observer traveled around the world so the technology is viable now.

Eletric engines are always reliable. There are slow boats out there that still breakdown.

yes tyey are

no, the generator only powers up the batteries, not the props

Sure, Salt water and hot hull... Need a crew who will always clean it with fresh water