Silent Yachts Electric Cat

[Bullshooter]

Originally Posted by Hyprdrv

"Why not ask an actual owner what power setting he typically uses, and what his fuel consumption looks like? You can't dictate what power setting a user will use."

IF you go back and look at some of my posts you will see I've owned a Lagoon 410 S2E since 2009. The boat was built in 2004 so I've been around for a while. I'm just glad people are starting to take ES (electric sailing) seriously.

So to answer the question, under genset I do 6 knots and burn a little less than 1gph. That puts a little back in the batteries and the rest to run the motors. Lithium's by the way can be discharged to 10% with no damage.
This is on a sailboat so unless there is no wind the genset isn't started. Under sail and doing better than 5 knots I regen through the prop, not a lot until I get to about 10 knots.

I have also spent my money on removing any discharge from the Propulsion pack and have 600 watts of solar. If needed I can tap into the Propulsion pack to charge the house bank. In 4 years I have only tested that part of the system.

O ya I'm more concerned about my 2, 25 gallons of diesel in my tanks going bad than running out of fuel in 10 years.

Steve in Solomons MD

I'm still impressed with Hyprdrv. He seems to be living proof that it is a viable direction, 11 years going, although I don't know if he is passage-making or what.

What about the Electric Voyage yacht in charter in the Caribbean at competitive rates? Has anybody heard any real reviews from charter customers? The review noted in a prior thread was obviously biased, but this could be a proof of concept for short range cruising.

[GrowleyMonster]

Originally Posted by barryglewis

Is this the nickel iron alckaline batteries that were used on some boats post WW2, being war surplus? They certainly worked, crewed on gaf
f ketch 1968 Plymouth to Sydney with them. The Sydney "experts" had never met them so they were discarded, rather than refurbished!

Too bad. They can last over 100 years. Ask Jay Leno. Not very efficient in terms of self disch rate and per lb energy density but they are all but bulletproof. Refurbishing basically consists of dumping the old (fairly envorinmentally friendly) electrolyte, rinsing them out good, and refilling them with lye solution and maybe a bit of some lithium compound or another, optionally. Also a bit of secret battery oil, to prevent oxidation. The secret battery oil can be bought for about $200 for a half pint bottle, NOS, or made from mineral oil and red dye. Very cool battery. They were used a lot in electric cars before about 1915, and also in some launches and canal boats.

[GrowleyMonster]

Originally Posted by Shaneesprit

Hmm, solar is only good for topping up an existing supply.
and those that state solar aircraft, and the solar flight at 50000ft
Well at 500000ft there are no clouds and the air is thinner and gravity is less, so not that relevant.
There are a few boats out there with electric drive but the only ones that work are engine powered, you need to realise the difference between an LED light and a motor!
Also if you were going to choose to make a vessel electric solar propelled, then you should choose a mono not a multihull. Cats have room yes but they only work if they are light weight.

Gravity is less? ROTFLMAO! No. Wouldn't matter anyway. Solar is EXCELLENT for topping up batteries because it is free, passive energy but a diesel generator is not, and the reduced acceptance rate reduces efficiency of diesel charging significantly. That's why so many cruisers only charge on the diesel to about 85% or 90% SOC.


You can, however, certainly use a solar array to charge batteries at ANY SOC percentage. You are trying to change the laws of physics here. Scotty says no don't go there.


Pure solar electric is indeed a hard nut to crack. Unless you are willing to settle for very low speed. Like on a sailboat. And there is nothing wrong with combining solar and a diesel generator with batteries and electric drive. It's the ultimate hybrid system, very flexible and still efficient because you are getting a lot of free energy from solar. And for cruisers under sail, who only need their electric occasionally, duty cycle has a lot less relevance.


I guess haters gotta hate. But I see the same tired old arguments from nattering nabobs of negativity all the time, even after everything has been patiently explained to them. However for anybody who believes gravity is reduced at 50k feet and this improves efficiency of electric propulsion in flight, I suppose anything is possible. Or impossible. Whatever.

[StuM]

Originally Posted by GrowleyMonster

However for anybody who believes gravity is reduced at 50k feet and this improves efficiency of electric propulsion in flight, I suppose anything is possible. Or impossible. Whatever.

He actually said 500,000 ft (154 km).

I don't think that there are any "aero"planes getting around at that height though. They might have a bit of difficulty generating any lift with their wings.
But he's technically correct. At 50,000 ft, gravity is "only" 99.47% of that at the surface
What effect that would have on the efficiency of EP is another matter.

[GrowleyMonster]

Originally Posted by StuM

He actually said 500,000 ft (154 km).

I don't think that there are any "aero"planes getting around at that height though. They might have a bit of difficulty generating any lift with their wings.
But he's technically correct. At 50,000 ft, gravity is "only" 99.47% of that at the surface
What effect that would have on the efficiency of EP is another matter.

Ooops my bad.

[Shaneesprit]

Far from hating solar I am very pro solar, where it can be used effectively, ok I hate to see a field covered in solar panels, that should have plants and animals in it, however I equally hate the fact that almost every new building is created without a Solar roof, no batteries needed just pay straight into the grid.
Solar projects like those in the Deserts of Chile also the way forward.
Personally I never gen my diesel or a generator to charge the batteries. I rely on Solar and reducing my power needs to the minimum.
I am even pro battery for cars, especially in the cities, although we are not ready for everyone to use cars for longer journeys.
The battery life is an unknown and the environmental impact of such numbers of batteries and the reproduction of cars because the batteries are dead can halve the life of a car at the moment . I just don’t think enough has been done to understand the long term effects, it never is - as always it’s jump on the latest bandwagon, as we all did with plastic.

[solartude]

From the video posted previously (

https://www.youtube.com/watch?v=4pFsvH78IPw

) one can get some real consumption figures around 2minutes in. The screen shows ~25kw consumption for 6.8knts SOG.

10kw of panels will provide ~40kWh of energy per day on average somewhere like Sydney Harbor (4 PSH - Peak Sun Hours) when using flat mounted panels. You can look up the PSH for your cruising grounds at https://globalsolaratlas.info

That gives us a daily max range of 11nm @ 7knts. Not exactly ocean crossing performance.

Thats also assuming no house loads too.

Ultimately I think its telling that of the 5 sold at the time of this article, 4 have been fitted with a mast and sails ( https://www.yachtingworld.com/boat-t...d-yacht-118869 )
Adding a mast and sails will drastically reduce the ability of the panels to generate power...


Its a nice idea but solar pushing a 25 ton roomaran isn't going to work.

[GrowleyMonster]

Originally Posted by solartude

From the video posted previously (

) one can get some real consumption figures around 2minutes in. The screen shows ~25kw consumption for 6.8knts SOG.

10kw of panels will provide ~40kWh of energy per day on average somewhere like Sydney Harbor (4 PSH - Peak Sun Hours) when using flat mounted panels. You can look up the PSH for your cruising grounds at https://globalsolaratlas.info

That gives us a daily max range of 11nm @ 7knts. Not exactly ocean crossing performance.

Thats also assuming no house loads too.

Ultimately I think its telling that of the 5 sold at the time of this article, 4 have been fitted with a mast and sails ( https://www.yachtingworld.com/boat-t...d-yacht-118869 )
Adding a mast and sails will drastically reduce the ability of the panels to generate power...


Its a nice idea but solar pushing a 25 ton roomaran isn't going to work.

You are missing the point. Any realistic look at this boat's specs will tell you that you aren't going to get good speed and good range out of just the solar. But back to the 11nm... that is 11 free nautical miles. 11 miles that you didn't have to burn any diesel to get. Don't think of the solar panels as the sole source of power. Or even the main source of power if you want to make 7kts and motor all day long. It is just free energy for free miles. You have IIRC two diesel gensets and the generators, charge controllers, and BMS are optimized for rather good efficiency, probably better than many straight diesel/gearbox/shaft/prop installs.



It is pretty hard to say it isn't going to work, when it is already working. It might just not be working the way you would prefer. Hybrid solar/electric/diesel is not for everyone, that's a fact. Only a small market segment will really be happy with the added complexity and having to actually be something of an engineer to get the best out of the system.



You are correct about shading the solar panels. Now when there is a good breeze for sailing this franken-boat, optimum performance by the solar array is not such an important thing. When the boat is not being sailed, it would be nice to be able to get the rig out of the path of the sunlight. I think it would be cool to have a single tabernacle mast with a hydraulic stepping ram. The mast would have to be well forward or aft, else it would also have to be tracked, for minimal overhang fore or aft. As much as I like to sail though, I think maybe I could do without sails on that boat. The hull wasn't really designed with sailing in mind. I think it would be a real dog to sail to windward, in particular.

[valhalla360]

Originally Posted by GrowleyMonster

that is 11 free nautical miles.

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.

[GILow]

And don’t forget, aside from the capital investment needed for those 11 free miles, the embedded carbon footprint of manufacturing the panels and associated gear is astronomical. There’s no way this thing can pay for itself either financially or ecologically.

[threeseed]

I would also just add that the next few years for solar yachts looks very promising.

Silent Yachts is using I believe Sunpower 360w panels. Whilst the Chinese manufacturers e.g. Trina Solar have released 600w this year in the same size and have a credible roadmap to get to 800w+ in the next few years.

There are also companies like Oxis Energy prototyping next-gen Lithium-Sulfur batteries designed for aircraft which could make their way into a Silent Yacht and is promising 2-3x the capacity for the same space.

Combined and it could be possible to sail at 7kn 24/7 without diesel.

And these are real shipping products and ignores the unprecedented amount of R&D that's going on in solar and batteries.

[StuM]

Originally Posted by GrowleyMonster

You are missing the point. Any realistic look at this boat's specs will tell you that you aren't going to get good speed and good range out of just the solar. But back to the 11nm... that is 11 free nautical miles. 11 miles that you didn't have to burn any diesel to get. Don't think of the solar panels as the sole source of power.

But that's the way they sell it

"SILENT-YACHTS are the first and only ocean-going production yachts in the world which are exclusively powered by solar energy.
This means nothing less than being fully solar sustainable while having the possibility of unlimited range with zero emissions."

"A SILENT-YACHT can virtually cruise for weeks without fuel or the need to start the generator."

"Overall, this leads to high levels of efficiency enabling fast and self-sustaining propulsion."

"The photovoltaic modules recharge the batteries and are the main power source of our yachts....sufficient to power all household appliances, all devices that you need for your comfort and even the propulsion system."

"A SILENT-YACHT can cruise for up to 100 miles a day without fuel."


Need I quote further?

[StuM]

Originally Posted by threeseed

Silent Yachts is using I believe Sunpower 360w panels. Whilst the Chinese manufacturers e.g. Trina Solar have released 600w this year in the same size and have a credible roadmap to get to 800w+ in the next few years.

You may like to check your facts. Trina Power vertex panels do indeed generate 600 watts, but they are not "the same size". They are still less efficient than Solarpower (21.3% v 22%).

https://www.solarreviews.com/manufacturers/trina-solar
"The vertex series feature the same multi-busbar MBB interconnections, as used on other Trina panels to achieve efficiencies up to 21.3%. More notably, they are the first panels built on the new larger format 210mm monocrystalline cells using the unique 1/3 cut cell size (as opposed to the common half-cut cells). The high-power vertex panels are a much larger format coming it at 2.1 -2.3m high and 1.1-1.3m wide."

Originally Posted by threeseed

There are also companies like Oxis Energy prototyping next-gen Lithium-Sulfur batteries designed for aircraft which could make their way into a Silent Yacht and is promising 2-3x the capacity for the same space.

Combined and it could be possible to sail at 7kn 24/7 without diesel.

Greater battery capacity will have zero affect on how far and how fast you can sail on one day's solar input

[threeseed]

Originally Posted by StuM

You may like to check your facts. Trina Power vertex panels do indeed generate 600 watts, but they are not "the same size". They are still less efficient than Solarpower (21.3% v 22%).

Actually Silent Yachts I believe is still using the 20.4% version 2 panels. And Trina Solar do have the commercial sized ones at 600w but I believe as part of the 600w Chinese alliance they are aiming for the standard home sizes as well.

And as I mentioned it's not like everyone is stopping. Solar is rapidly advancing each year.

Greater battery capacity will have zero affect on how far and how fast you can sail on one day's solar input

Ideally you would want both the panels and batteries improving so that you can capture more of the solar input. But even today a 3-5x improvement in capacity would be useful for island hopping.

[StuM]

Originally Posted by threeseed

Actually Silent Yachts I believe is still using the 20.4% version 2 panels. And Trina Solar do have the commercial sized ones at 600w but I believe as part of the 600w Chinese alliance they are aiming for the standard home sizes as well.

Can you provide a link to data for these 600W standard/commercial sized panels? I've not been able to find any trace of them. They would have to have an efficiency of around 37% which is unheard of for commercial panels.

But even today a 3-5x improvement in capacity would be useful for island hopping.

No matter how efficient your energy storage is, it doesn't alter the amount of energy available from a day collecting solar. Silent 55 can have anything from 75 to 225 kWh of storage. That doesn't alter their daily range on solar by a single mile.