How much electrical grunt

[Guest]

Not that expensive Wheels. The batteries are the largest part but using lead acid somewhere around $2400 for 48 volts at 220 amp hours. The big plus is the amount of power for the house loads. Also the solar power that is available is harvested better with larger batteries and more panels. I would be very happy motoring at 3 knots on just solar power. With an hybrid you have a generator that will pump out current at quite large rates. the extra complexity is the problem as I see it.

[rigger 47]

Bbay - how many years do you expect to get out of the bank of Batts?

 

Some batt boats I know of get between 3-5 years. On at least one occasion due to a cell failure a bank got change after 2years.

[grant 40]

Bbay - how many years do you expect to get out of the bank of Batts?

 

Some batt boats I know of get between 3-5 years. On at least one occasion due to a cell failure a bank got change after 2years.

 

The larger the batteries get the better life you should get. I've had 12+ years out of lighthouse batteries, they were 1100ah at 2volts, but still plain lead acid batteries. Larger banks would tend to be better regulated and charged and not discharge too deeply too often

[wheels 543]

Not that expensive Wheels. The batteries are the largest part but using lead acid somewhere around $2400 for 48 volts at 220 amp hours.

220Ahrs wouldn't get Squids boat out of the Marina.

I know there is this "nice warm fuzzy" idea of having the basic need of power, but in reality, it isn't a reality. You need power (as in engine Hp) when you need it and that is becoming more and more so today with Marina's becoming tighter spaces, more idiots on the water to dodge. I could goon.

 

So lets just say we have as example A, a 50Hp engine to move our example boat around. That is a fairly middle of the road engine size. That is 37.5Kw of electric motor. Most Electric motors in that size are much higher voltages than 48V. You would be looking at 180VDC. That is a lot of cells and some serious wiring (not amature) and you need 660Ahr of battery Bank to get around 15minutes of solid 37.5Kw of electric push. After 15min (there abouts) the banks won't be able to produce enough juice and power starts to drop off fast. Remember, you have to use Start batteries for high power drain like this. House batteries just won't do it. So you need far far more power capacity than 660Ahr so you get your 37.5Kw delivered for an hr. Then you have to charge it all up again. That's going to take a big boy charger. How long have you got??

Good hand made FLA batteries, well maintained, can give a good service life, but they are horrifically expensive and very very heavy. I struggle to lift just one of the German 12V FLA units in my boat. If we talk about Lithium, that is just super horrifically expensive and chargers are also super horrifically expensive.

To finish off, systems like this are also high maintenance. They need carefully looking after. They had an engine "crew" in a Submarine. They constantly monitored and tinkered looking after the banks and gear. Most want a simple system that you turn the Key to go and turn the Key to stop.

[Bad Kitty 252]

24hrs @ 5knots is a big ask.

I'm interested in this sort of thing also, but unlike squid quite happy to burn diesel as well and I still can't find anything that works yet. Only thing that would really work for us is a hybrid system where electric engines run off batteries for a little motor round the corner for a dive, or get out of the marina or that type of thing. Say 1 hour @ 6 knots, using 2 electrics in the cat, that's pretty achievable.

But then when you need to keep going, or for whatever reason, start the genset & run the electric motors straight off that.

And that's where it all gets too hard.

Current systems for sale require you to use the genset to charge the batteries & fun the motors off them, which just doesn't work.

So I can't see how it would work for us just yet, but fingers crossed.

Those diesel electric hybrids are common in big commercial stuff so maybe we'll get trickle down some day?

[Guest]

You don't need 50 hp to get out of the marina Wheels, maybe ten! The electric motor would be better in the marina than the diesel! Ten hp would be fine for marina maneuvering and for motoring slowly on light air days. Want more grunt use the diesel. With the hybrid system you can get away with smaller batteries and electric motor because you can hit the diesel starter at any time and it will also charge the batteries very rapidly. Yes you would need to choose your batteries very carefully Rigger, I believe the electric car guys are having good results from Lithium types but wow, bring your money. I have 6 x 2.3 volt cells in mine and one of those went out of action but replaced under warranty.

[rigger 47]

Current systems for sale require you to use the genset to charge the batteries & fun the motors off them, which just doesn't work.

There are systems available that charge the batts and run the gear - costly but available. 12.5kW approx. 85k Mind you that included installation, fuel tank, but not a drive train.

[wheels 543]

You don't need 50 hp to get out of the marina Wheels,

No one is nuts enough surely, to want to spend lots of money and gain so much complexity just to move around the Marina in silence. If getting out of the marina is all you want to do, then a 5hp outboard you can then stow away afterwards is all you need. An installed motor is much more than just a marina mover. It is as important as the sails are. I know from experience I would not be wanting to exit or enter Gisborne Harbor entrance without a decent motor and some solid performance from it.

[wheels 543]

Not sure a mega capacitor will be the answer either. Sure, a capacitor is unique in that it can be charged rapidly, but the downfall in any charging system is about the Sum Total of energy being created, sent along cables and then charged into the storage device. 2000A is a lot of current to try and produce and store rapidly. So you may have a Capacitor capable of, but the issue becomes, how do you get the current to it in an easy means. So the limiting factors would be cable size and being able to produce the high charge. It could be done in one way, that being upping the Voltage to hundreds or maybe even thousands of volts and then converting that back down again, but there in becomes a complexity again.

A Battery is about storing energy chemically, which means more energy in given "footprint". A capacitor requires square area of plates to store electrons. So it will always be limited to it's large physical size. Where a capacitor works well is in short duration large scale current storage and supply. As in, a Vehicles braking system charging a capacitor and the accelerator then supplying current to an electric motor to get car back to speed before petrol takes over again.

No matter how we keep looking at the current technology, the case for the Diesel engine is still a rather strong one. I think we are still along way off a really good alternative to a combustion engine. We need a major paradigm shift in producing motion from energy.

 

Oh and by the way, if anyone thinks Electric is silent, then you haven't heard an electric system running. Give me a Diesel anyday

[Guest]

Until diesel hits $5 / litre.

[wheels 543]

5/ltr may sound expensive Squid, but how many ltrs per yr do you think you use?? That totals to what dollars? How many ltr's will you have to use to pay for an electric set up? An electric set up of $80K is still a lot of fuel if you look at it that way. Plus the on going battery expense added to that.

I think the "need" for an alternative system has to be more than just fuel cost. And in saying that, I think it fair to say, most of us approach the alternative power issue from a point of view of wanting to be just that little more "free". The ability of being able to snub that fuel berth at the Marina. One further tie to the world cut, so to speak. But at what cost do we hang our heads and realise one or two ties to the world are still inevitable.

[rigger 47]

Oh and by the way, if anyone thinks Electric is silent, then you haven't heard an electric system running. Give me a Diesel anyday

 

Have you tried a small steam engine?

9knots and very little noise, unless the safety lifts

[Guest]

The hybrid system appeals to me because it uses the diesel as a generator which is handy to have on a battery powered vessel giving range, 240 volts if needed ( you could probably run a small electric oven, certainly a microwave. Also, With large batteries and a good solar array one can harvest a lot of energy from the Sun. So you can have your cake and eat it! I think people underrate the ability to get an extra knot or two in light conditions which this sort of drive would deliver very quietly.

Wheels, I've been coming into and out of Gisborne harbour with a motor that would only give 2 knots when heated to operating temperature with no problems at all. The gearbox was rooted and lost drive as it heated! All good now though, re built the gearbox, re conditioned the head on the isuzu and re conditioned the cooling system and its all go now. I had to sail out one day when the prop came away due to a washer breaking! I would have no problems with the range of a battery powered system and an hybrid would be fantastic. Hybrid is a lot of extra complexity as I said previously, and a yacht is already very very complex system. Be a sailor not a motorist!

[Guest]

You're right Wheels, which is why I will not throw away the perfectly good ICE in the boat. But I will try to up my generating capacity from solar and maybe wind till the ICE is purely for locomotion (and watermaking when necessary), and watch with interest as the technology around the electric drives develops and hope it has arrived by the time my ICE breathes its last breath.

 

BTW I think $5/l will happen sooner rather than later then carry on up.

[wheels 543]

9knots and very little noise, unless the safety lifts

Steam and a Steam whistle. Com'on who ain't going to be pulling the cord to that given the chance

Give me Steam....hmmm,suddenly remembers words to a song.

[Guest]

Yeh remember when it was nearly a dollar. When lithium batteries come down in price and maybe up in capacity a bit its a goer.

[rigger 47]

BTW I think $5/l will happen sooner rather than later then carry on up.

 

Veg oil might be an option then?

$6.95 for 2L

 

Now what do you need to do to be able to use it in the ICE?

[Guest]

http://www.caranddriver.com/features/ho ... etable-oil

 

So today we walked up and down a few fingers at GH (they leave the gates open for people like us) and stood alongside all the wind generators we could to guesstimate the noise output. Early indications are that more blades with less diameter is quieter than fewer blades and greater diameter - discuss.

[wheels 543]

Early indications are that more blades with less diameter is quieter than fewer blades and greater diameter - discuss.

Depends on several variables that you are probably not getting a good real world scenario in the Marina. Wind genny's tend to be noisiest at peak production. In the Marina, boats will have fully charged banks. So the genny's are probably not working properly.

Blade design and finish is the greatest single point to quieter operation, with wind speed (thus blade speed) encompassed in that. So in theory, because each blade produces noise, the less blades, the less noise supposedly. But then that can come at a compromise to blade area which is just like having more sail area meaning more force. Also the blade design differences mean differences in type of noise. All in all, It's complicated.

[rigger 47]

if you have smart phone you an download a noise meter for free.