electric/hybrid propulsion for small ferry

[DaveB]

Hi,

I'm workin' on a concept design for a small ferry:

~40 LOA
40-50 passengers
~10000 kg

I'm thinkin' it'd be nice to have 50kW available... but the average power used to propel at 6.5 kts for 10 min (~2km) twice or four times / hr might be much less... to the order of 20kW. If twice can plug in for the half hour between runs (5 min allowed for tyin' up n' loading&unloading at each end)

-> Need to run for at least 20 min with 30 possibility of 30 min charging in between...

Do my numbers make sense? It's a first stab so I'm tryin' to be conservative, but I'm not sure of the cost/availability of electric power systems... there might be room to do it with less power...

Is hybrid (electric with generator running) or straight electric power feasible?

How much power could I get outta an electric motor for an application like this n' roughly what would the system cost?

Are there any references (books/journals/websites/companies) that you know of?

Cheers,

Dave

You realize each time ENERGY is made to change it's form a big loss of it occurs? Very low bottom line. and a higher maint. cost. Diesel-Diesel, insurance, USCG, electrical fires, my goodness the list grows very fast. I have not really started.-------------Very long underwater cord, would give a great bottom line. No joke. Absolutly true if you could get safety approved. Electrically I can prove it. But safety boards will stop you. I think. Never tried it.

[DaveB]

Originally Posted by Richard Petersen

You realize each time ENERGY is made to change it's form a big loss of it occurs? Very low bottom line. and a higher maint. cost. Diesel-Diesel, insurance, USCG, electrical fires, my goodness the list grows very fast. I have not really started.-------------Very long underwater cord, would give a great bottom line. No joke. Absolutly true if you could get safety approved. Electrically I can prove it. But safety boards will stop you. I think. Never tried it.

Yeah... efficiencies (or lack there of) are huge, but electricity's one of the cleaner ways of movin', there's 'main-lines' everywhere n' I think it's the kind of thing worth askin' about....

The application's about as close as you can get to bein' teathered without bein' teathered... short runs, can recharge at either end... I dunno...

Thanks for your two cents... seems ppl. aren't interested in this one... need to find a manufacturer or better yet a consultant who's familiar with the industry...

Cheers,

Dave

[D'ARTOIS]

The waterway you want to cross, is there any current in it? Does it run with a nice current?

Five minutes return-time is a bit optimistic for un- and uploading, make it 10

[DaveB]

Originally Posted by D'ARTOIS

The waterway you want to cross, is there any current in it? Does it run with a nice current?

Five minutes return-time is a bit optimistic for un- and uploading, make it 10

no current...

Perhaps... the schedule is such that it leaves one side every half hour so I guess I'll have to speed it up to allow more time... 7/8 min each or something...

Thanks for your input!

[B. Hamm]

Originally Posted by DaveB

Yeah... efficiencies (or lack there of) are huge, but electricity's one of the cleaner ways of movin', there's 'main-lines' everywhere n' I think it's the kind of thing worth askin' about....

The application's about as close as you can get to bein' teathered without bein' teathered... short runs, can recharge at either end... I dunno...

Thanks for your two cents... seems ppl. aren't interested in this one... need to find a manufacturer or better yet a consultant who's familiar with the industry...

Cheers,

Dave

Well, that's one subject that has a fair amount of controversy about electricity being the "clean" way to move. The power has to generated somewhere so it's not necessarily any cleaner depending on how it's generated. Coal plants are cleaner than they used to be but it's debatable if they are cleaner than a smallish diesel and certainly arn't as clean as something like bio-diesel.

Bill H.

What is the across the river distance and what are the average and highest windspeeds you expect to run in? Double pointed bow ferry design? Or a used one of approved Ferry Duty, approved by all gov. and Insurance agencies?

You realize that if the water is deep enough. You can run it back and forth on a submerged and anchored to the bottom cable set up. Then, only a EMERGENCY on board motor is needed if the ferry breaks loose or it needs to release itself due to a underwater cable jam. All power motors and controls are then on shore and a piece of money making cake.

B. Hamm. You are right about electricty being dirty and a waste of everything. If you take into account all the companies who make everything needed to make and transport it and maint. It is the dirtest and least efficent Business in the world. BUT IT IS easy to use at a site. Consider if each building generated it's own power. SMOG 20,000 feet high.

[B. Hamm]

Sure the alternative a central plant producing electricty isn't a good one, but that still doesn't mean that making things run on electricity instantly makes them non-poluting. It's a common misconception.

Bill H.

[FAST FRED]

It takes far longer to charge up a battery than run it down.You might need to swop out the power pack after every run , heavy work!and expensive!

For your needs a flywheel as the Swiss use in their trolly cars would be a far better choice as you can respin it with a LOT of power in a very short time.

FAST FRED

Dave? Have we helped or hindered? All the frustrated designers.

[DaveB]

Hi Richard (& guys),

You've all helped a lot... thank you very much... sorry I've taken a bit of a hiatus from the conversation... I've been on the electric boat list too n' just getting back into the swing of school so I've been gettin' stuff out of storage n' also tryin' to get in grad school apps... all just excuses... not good that I've been away...

A little overwhelmed with the electric options (diff. motors, batteries etc... no real std... solomontechnologies seems good... but still not sure what else is out there)

Will try n' post some more ideas soon... (bring together info I've got... )


Thanks for askin'!

Cheers,

Dave

[Tim B]

I seem to remember that there's a boat with a wind turbine floating around somewhere... now you can't get much cleaner than that and still use electricity. Failing that (and I know America's not too keen on this generally) a couple of wind turbines on the shore which a set of batteries to provide power in nil-wind situations. You can then power the shore stations as well. and once you get over the initial installation costs, it's practically free!!! it would of course be fairly easy to run power into the boat from shore down a decent sized cable at very high voltage and low current. depends how windy it is, of course... but it saves the efficiency losses and weight of batteries.

Good Luck,

Tim B.

[DaveB]

Hi Tim,

Thanks for the ideas... the land based turbine sounds like a great idea... actually one not far from where it'll operate... not sure how well it's doin'... think it might be more of a 'political statement' than an ideal site for one... I love 'em though... seem to make so much sense...

Cheers,

Dave