Electric Propulsion (Podmaster?)

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yochan80

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Hi,

Have just bought a new (to me) 30ft sailing yacht which needs a new engine. I was wanting to go down the 100% electric route instead of replacing the current one with another diesel. Has anyone replaced theirs or have any experience of electric 'engines' on yachts?
I noticed the Podmaster in this months PBO but can't find a dealer in the UK with any more info regarding how to buy, cost etc :confused:

Cheers
 
If I were you I would study the technical specs very carefully.

Be sure you know just what the electrical consumption of a suitable unit would be. How large a battey you would need to give the sort of range you would want and how you would recharge it.
 
We have done all this before. Check the arithmatic before you go any further.

A large leisure battery has less usable energy than a gallon of diesel. Wold you set off with only one gallon in your tank?
 
yochan80 said:
Have just bought a new (to me) 30ft sailing yacht which needs a new engine. I was wanting to go down the 100% electric route instead of replacing the current one with another diesel. Has anyone replaced theirs or have any experience of electric 'engines' on yachts?
I noticed the Podmaster in this months PBO but can't find a dealer in the UK with any more info regarding how to buy, cost etc :confused:
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The Podmaster isn't a "100% electric route", you have to generate the electricity. There are losses involved in generating electricity and then using that electricity to drive an electric motor to drive the boat. So, in many cases, you might just as well have an ordinary diesel engine.

If you're able to truly benefit from some other aspects of Podmaster (eg steerable thrust), that could sway your decision.
 
When we were going to put the Anderson 22 back into production, I as a sort of technical director was very keen on seeing if we could use electric drive.

This was partly because I'd worked on the French canals, and had visions of gliding along silently using very little power, with ample sunlight for solar charging in summer at least - the A22 is very easily driven, and when out there I'd met a couple in a 23' Magyar where the husband simply pulled the boat via a line over his shoulder to the towpath, once the boat was moving it was easy.

HOWEVER, I had a long hard chat with a German electric drive specialist whose expertise went back to, you've guessed it, U-Boat submarines.

To cut a long story short, a yacht would have to be purpose built from day 1 with the batteries as part of her ballast and hull shape.

Even then you're not home & dry, it's just about do-able but the cost would be eye-watering with strict limitations on range & power; better to wait until Duracell are flogging Fuel Cells in every corner shop !
 
Nikki Perryman (who writes a monthly column for Classic Boat magazine) described in one of her columns how they converted from a diesel to an electric motor for their 35' wooden Lion class sloop 'Siandra' - a scanned copy of this article is attached below.
It is probably easier to read it if you save a copy to your computer, as the script is very small otherwise.

NikkiPerryman-electricmotors-1.jpg


The Siandras are good mates with AndieMac (who usually posts on the Mobo Forum) - he recently sent me some news from them re how after 3 years of constant hassle with the electric motor they have finally ditched it - they said the motor had so many defects, and the manufacturer was not interested in fixing them, so Nikki asked for their money back - and they were refunded (in full I think).

We installed a new 2nd hand Volvo in our boat last year after the previous Volvo blew up - I must admit that I was seriously thinking about going for an electric motor back then, but in the end it was easier to just get another little diesel.
Although I think that electric motors would be / are ideal auxiliaries for the new types of 'Daysailer' yachts now being built (especially in North America).
 
I'm sure that in 10 years time a good percentage of new inboard engines will be electric but what the fuel will be to charge the lithium batteries remains to be seen. Now that electric cars are rapidly increasing in number, the unit costs will tumble - after all, our diesels were never designed as marine propulsion units, we've got them because someone adapted a road transport engine.

Have a look at these guys http://www.re-e-power.com/
 
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Think you problem will be power output and what you propose to use the boat for. We have a 10m boat and it used a 3ym20 which producers 15.3kw of power and pushers her along happily at 5knots. Your electric alternatives produce about 5kw of power. Added to that the cost of batteries and the recharging you could be on to a looser.

We carry a couple of extra cans of diesel just in case. Suppose you could fit a lightening rod and pray for rain.

Having thought about this and before you spend vast amounts of money why not fit an outboard engine with the same power output and see what it performs like in you normal sailing area.

..
 
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A Cautionary Tale (True Story)

A friend of mine in Skye built his own boat - 29 foot long, a labour of love and of great skill over three years. He fitted her with an electric propulsion system and a variable pitch propellor that was rigged to charge the batteries when the boat was sailing.

He had twenty four gel-filled batteries in the long hollow keel to provide the power and also acted as ballast. He estimated that 6 hrs sailing time would give him electrical power for 1 hour motoring. Under power the electric motor gave up to 8HP, and the boat was utterly silent.

Because I was convinced that he was being over optimistic on his 6/1 generating/propulsion factor I urged him, before he left Skye, to at least take a small petrol generator with him to charge his batteries if they were completely flattened. This he eventually agreed to do.

Unfortunately it could all have ended in tragedy. Near the Isle of Mull having had had light winds (it's either feast or famine in that part of Scotland) with no power left in his batteries he ran the generator, put on the kettle for a cup of tea and then realised he needed to top up the generator which was in the cockpit. You can probably guess what happened. There was a vapour flash from the cabin stove to the fuel going into the generator tank and the whole lot went up. He escaped with his life by diving into the sea and clambering into the inflatable he was towing. His beautiful clinker-built yacht burned to the waterline and sank in very deep water. He was picked up by the only other yacht in the area which, fortunately, had spotted the fire.

Take heed of all the advice given on this thread and then buy yourself a new diesel - cheap, reliable and safe.
 
Red Admiral said:
A friend of mine in Skye built his own boat - 29 foot long, a labour of love and of great skill over three years. He fitted her with an electric propulsion system and a variable pitch propellor that was rigged to charge the batteries when the boat was sailing.

He had twenty four gel-filled batteries in the long hollow keel to provide the power and also acted as ballast. He estimated that 6 hrs sailing time would give him electrical power for 1 hour motoring. Under power the electric motor gave up to 8HP, and the boat was utterly silent.

Because I was convinced that he was being over optimistic on his 6/1 generating/propulsion factor I urged him, before he left Skye, to at least take a small petrol generator with him to charge his batteries if they were completely flattened. This he eventually agreed to do.

Unfortunately it could all have ended in tragedy. Near the Isle of Mull having had had light winds (it's either feast or famine in that part of Scotland) with no power left in his batteries he ran the generator, put on the kettle for a cup of tea and then realised he needed to top up the generator which was in the cockpit. You can probably guess what happened. There was a vapour flash from the cabin stove to the fuel going into the generator tank and the whole lot went up. He escaped with his life by diving into the sea and clambering into the inflatable he was towing. His beautiful clinker-built yacht burned to the waterline and sank in very deep water. He was picked up by the only other yacht in the area which, fortunately, had spotted the fire.

Take heed of all the advice given on this thread and then buy yourself a new diesel - cheap, reliable and safe.
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Whilst that's a sad tale, it only reflects the foolishness of your friend - not any inherent danger with either electric propulsion or petrol generators.
 
pvb said:
Whilst that's a sad tale, it only reflects the foolishness of your friend - not any inherent danger with either electric propulsion or petrol generators.
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Absolutely. Plus the suggestion to charge 24 batteries from a little petrol genny was misguided as it would barely keep up with their natural discharge rate :D

It's only brave early adopters that are forging a way forward on electric propulsion, 5 years ago the units were largely rubbish and underpowered but there is real progress happening, mostly on the back of the changes in the automotive industry, in a decade there will be off the shelf units that will transform motoring a sailboat into a quiet, and vibration free experience. Thank goodness for the early adopters willing to have a go rather than just sticking another lump in.
 
BabaYaga said:
Another alternative:

http://www.ozecodrive.se/OZecoDrive/Eng/IndexOZecoDriveEng.html

This company has made a number of such installations.
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And some useful real info too, even in a small boat with 800 AH installed you get less than 60 mins at full power even though you may get a day at a moderate cruising speed. This is as ever one of the problems, storing electricity takes a lot of space and weight or an awfull lot of money for exotic battery chemistry, and the higher the power you use the less you have. You may well have 800AH at the 20 hour rate but that will fall dramatically as you draw more power.

The real answer for electric drive for yachts is the fuel cell but they are still pretty pricey too.
 
Nuclear power is the way to go.

When the first motor driven vehicles were driven in public, somone hd to walk in front carrying red flag and the speed ws limited to a walking pace due to fear for public safety.

If the same hysteria, fear and panic that surrounds nuclear energy could ever be put aside (we will have to in the not too distant future although we are in denial) then this is the way to go..
 
Thanks for all the food for thought. Some serious thinking and discussion need with the other half! :D

I see Vetus are doing a 100% electric drive as well as a hybrid diesel, maybe the hybrid would be a good choice to satisfy my eco desires!

Anyone had any experiance of these 2?
 
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