Silent Yachts Electric Cat

[mcarthur]

Solar is looking better, but we are still only talking 0.5-1% efficiency gain per year or two. The bifacial have some benefits (1-2%) if you can situate them well enough to take advantage. Maybe they'll be some other bigger change. But 1% per year takes a current 21.4% 10kW to a 26.4% and 12.3kW in the same surface area in 5 years time. So if someone was holding off going solar-assisted now for better efficiency, and can only have the surface area on their boat for 10kW for good panels now (LG Neon 2 or Panasonic HIT for example), that will only increase to 12kW in 5 years.

What solar does is give an ongoing energy source - that doesn't need regular $$$ like a fuel bowser - for a percentage of time of passage. And that percentage of time is what saves the regular $$ output.

It's the same as sails - they require little/no regular $$$ output (daily/weekly/per nm), but do eventually. They also cost the planet a lot to grow/make, just like solar panels do.

Silent are incredibly useful as a leader in the area. Not my choice, even if I had the money, but still a leader. On the other hand, it's possible to get solar-assisted benefits ($$, noise, maintenance, fossil-fuel daily use) on some existing boats. For our boat, estimates are 8-12hr diesel and 8-12hr electric-only, with solar assisting a little but a significant "little". Solar helps much more on 6-8hr days compared to 24hr days!

[GrowleyMonster]

Originally Posted by valhalla360

I generally love your posts on electric propulsion as you are much more balanced and realistic but I have to call out...there is no such thing as free power.

If you can show me where I can get a free solar system including installation and integration, we can talk free power. But really, it's mostly paying for power up front.

Not that it's bad or you shouldn't do a solar propulsion. If it makes you happy to mess about with electric propulsion or it makes you feel like you are saving the earth, go for it...but it's not free.

True, at least technically. Then again... diesel engine? No, of course the panels aren't free. The energy source is, however, and otherwise goes unused.



Don't get me wrong. I am not going out on a limb and recommending everybody line up to buy this boat. I just wanted to show folks what is being done and how far the state of the art has advanced. Would I buy one? No. Well, maybe. But I would be more likely to build than buy because I think I could beat their figures and tailor the specs better for my usage pattern and maintenance/tweaking/hacking ability.

[valhalla360]

Originally Posted by GrowleyMonster

True, at least technically. Then again... diesel engine? No, of course the panels aren't free. The energy source is, however, and otherwise goes unused.

No, not just technically. It's true.

I hate to call you out because you are more balanced than many of the proponents of electric propulsion but lots of talk about "free power", "zero emissions", etc... get thrown around.

If it's better than diesel, simply do an honest comparison and the data will show it without resorting to...we'll call it exaggeration but for many that's understating what is happening.

[jbinbi]

Was looking for a great loop boat, and came across this. They have been doing these for about7 years and have a few hundred boats of various sizes.

https://www.greenlinehybridusa.com/yacht/greenline-40/

They have 2kw of solar, a ton of Li battery, and the engines drive a generator to recharge the battery bank. All appliances work off of AC , the air cond via an inverter, the air cond as well. 26kWh (~2000 Ah @ 12V) of battery. The solar keeps the batteries fully charged on sunny days in the summer for appliances.

The battery bank will run the boat for about 20-30mi at 5kts. The engines will recharge the bank in about 1 to 2 hours. So in theory you could go 30 mi using no fuel, another 20mi using 3 gal and be fully recharged. I don't think you could get far using only solar for propulsion, but the boat was not designed for this.

I am not saying we are there yet with using no fuel, but for someone doing a great loop day of 50 mi, this gets you 50% of the day with no sound and not using dino juice.

I wish they had a fly bridge model for this size, I would seriously consider it for myself. A step in the right direction. Or if Silent made something smaller than 55'.

[MountainStone]

Silent Yachts announced In their October newsletter last year they are building a 44. No specs yet, but good chance of covering at least 100 miles per day without running the generator.

[StuM]

Originally Posted by MountainStone

Silent Yachts announced In their October newsletter last year they are building a 44. No specs yet, but good chance of covering at least 100 miles per day without running the generator.

For a given value of "good".


IOW, yet another meaningless claim, probably created by a PR drone.


https://www.silent-yachts.com.au/models/silent-44/


Now that it's in production, please provide an actual miles per day claim.

[Shaneesprit]

There is no point claiming a mileage at new, please give me the 10 year end of life distance,
I often sign off Battery installations for clients, they are all sold on end of life and tested until they are dead when new to calculate the end of life minutes sold / purchased sometimes they will actually last more than 12 minutes at full power when new.
For the solar it’s fully weather dependent and as such weather dependent,
and charging batteries with a generator and believing your Environmentally sound? Well my thoughts on that could be considered offensive to someones intelligence so I will keep them to myself

[bloeffl]

I’m surprised at the amount of negativity towards a new and clean technology! These yachts do have generators for longer or faster trips, but the owners travelled on the test boat for a year without using it, and the Atlantic crossing (in feb) they said they used it 3 hours a night to get across faster. Are they perfect, no. Do they look nice. I think so. 8 year battery warranty, 20 year panel, lifetime engine. No sail or rigging maintenance, no engine (outside generator). I hope to get one at retirement.
Happy Boating.

[Shaneesprit]

Originally Posted by bloeffl

I’m surprised at the amount of negativity towards a new and clean technology! These yachts do have generators for longer or faster trips, but the owners travelled on the test boat for a year without using it, and the Atlantic crossing (in feb) they said they used it 3 hours a night to get across faster. Are they perfect, no. Do they look nice. I think so. 8 year battery warranty, 20 year panel, lifetime engine. No sail or rigging maintenance, no engine (outside generator). I hope to get one at retirement.
Happy Boating.

It’s not negative to ask for the end of life mileage, that’s how you size batteries,
Honestly I am not a fan, it doesn’t work until you have a clean electrical supply to charge from, much like an electric car has potential, and a non plug-in hybrid - has some advantages, but a Prius using the same amount of fuel as a regular crappy car - but you also made batteries- so what’s the point

[Bullshooter]

Originally Posted by Shaneesprit

It’s not negative to ask for the end of life mileage, that’s how you size batteries,
Honestly I am not a fan, it doesn’t work until you have a clean electrical supply to charge from, much like an electric car has potential, and a non plug-in hybrid - has some advantages, but a Prius using the same amount of fuel as a regular crappy car - but you also made batteries- so what’s the point

I don't follow. I had a Prius for a few years, and got 45-50 MPG. I'm not sure what your point is.

[Shaneesprit]

The Prius like all none plug-in hybrids are a waste of resources. Even getting Banned as Taxis in some cities, not an outright ban but phased out as a minimum of plug-in hybrid requirement.
I am all for other people driving electric cars in cities, probably think diesel cars and possibly even petrol cars will get banned or taxed out of city’s as that kind of makes. sense. Make the pollution outside of the city where there are less people, I live to far from work to drive on a battery,
Side note - I will be using petrol for a good while yet. Burn oil for heating as I have no Natural Gas, well either that or wood. Because that’s the most efficient for me at this moment in time.
So applying that to a boat, if you need to run a generator to charge your batteries, you might as well just use the engine for propulsion in the first place. Carrying the weight of battery for propulsion and the weight of the generator to charge them, you convert even more fuel to kinetic energy to electricity to kinetic energy. Every time you convert you loose it’s as simple as that.
Or if you can truly live without the generator or plug-in and survive on Solar alone, maybe your doing some good, but the pollution created by making and recycling the additional batteries may or may not be better than the diesel was in the first place.
If we can create clean hydrogen maybe that’s a way forward for the future.