Fuel-Guzzling Yacht Industry Wades Into Hybrid Technology


#1

Who wrote that, 50m yacht can do what with what? from the front page
"The 50-meter (165-foot) yacht costs about $38 million. A new hybrid mode allows it to travel at 9 knots in virtual silence for about 9,000 miles using less than 12 gallons of fuel an hour, compared to about 26 gallons per hour when it’s travelling at 12 knots with its traditional motors on. In the hybrid mode, it uses diesel generators to power electric shaft motors instead of batteries, according to Conboy."
what crap, gen set to elec motor is like 12.% extra loss to start with
So we are saying 200hp to drive a 50 yacht at 9 kts. The gen sets will use half that
Add CPP props and I’l bet the same old big engines meet any DE consumption
Siemans should know they have been sued more then once and had to pay to convert a vessel back to direct drive at least once.

26gph at 12 knots, how would 2 x 3512’s do that?


#2

On a general level, the overall losses are about 12% between kW at the engine flange and kW at the propeller shaft. Even if smaller diesel-electric propulsion systems are somewhat less efficient than large ones, I wouldn’t expect the losses to be doubled…


#3

whatever the loss the article is trying to show a 50% gain?
There are already several DE megayachts out there, they must be wondering where they consume 50% more fuel they they should


#4

Do the math guys … a 50m yacht generally displaces around 725,000 pounds and has a hull speed of around 20 knots - or better, they easily exceed the old 1.34 SL ratio. The horsepower required to obtain 20 knots is around 3800, around 600 for 12 knots and around 350 for 9 knots.

Look up the fuel consumption for a typical 3800 hp diesel operating at those power levels.

It would make things a lot simpler if the OP had said what yacht he is talking about so we knew what engines are fitted. The efficiency of a modern diesel-electric is very close to a conventional drive system with the added advantage of being able to use multiple smaller engines to match operating demands. That 25 percent figure is total nonsense.


#5

very few 50m yachts can do 20kts unless light slim and no draft
Ones that can will have a pair of more then 3500hp engines


#6

Which describes most of them. Better than 20 knots max speed is very common for those boats with a cruise speed of around 12 knots. Look up Heesen, Christiansen, Westport, Proteksan … look 'em up, there are loads of them.


#7

with a pair of 3000hp engines
The ones you mention are all the light weight go fast, dont want to be out of the ICW models
but yes they do exist.
200hp to push them at 9kts??
Real Megayachts, Feadship Amels Lurssen, very rare doing 20kts