Electric inboard engine, equivelant diesel inboard.

[Tranona]

You are right about serial hybrids now appearing in some new builds but they all take up much more space than just a diesel and are inefficient at using energy. Nigel Calder carried out a big research programme with his first Malo on hybrids and came to the conclusion that any efficiency gains only occurred when the usage pattern was biased toward a lot of low speed work. While it might be an alternative to the other "mixed" systems you describe, it is never going to develop into a mass market product like hybrids have for cars (even if their benefits for many are illusory!). That is why I think it is a red herring. It just suits a small section of the market at this point in time and there is insufficient demand to encourage developments that will resolve its size and weight constraints.

 

[dunedin]

You are right about serial hybrids now appearing in some new builds but they all take up much more space than just a diesel and are inefficient at using energy. Nigel Calder carried out a big research programme with his first Malo on hybrids and came to the conclusion that any efficiency gains only occurred when the usage pattern was biased toward a lot of low speed work. While it might be an alternative to the other "mixed" systems you describe, it is never going to develop into a mass market product like hybrids have for cars (even if their benefits for many are illusory!). That is why I think it is a red herring. It just suits a small section of the market at this point in time and there is insufficient demand to encourage developments that will resolve its size and weight constraints.

Nigel Calder stuff was some time ago. And may depend on what type of motor he was using.
But as I emphasised, need to compare a serial hybrid to a comparable diesel engined offshore cruising boat - which also needs to find space for a diesel generator and increasingly a Watt&Sea - either on stern or for serious use through hull.
In terms of efficiency, the serial hybrid is massively more efficient than a typical diesel engine.
A typical cruising 45 footer would have perhaps a 75hp diesel these days. Great for the short burst of power needed occasionally. But cruising at 6-7 knots it will be running at low revs and very inefficient.
By comparison with a good serial hybrid, the electric motor is very efficient at low power mode (and 6 knots is well below hull speed for a modern 45 footer (with 42+ ft waterline). If doing a long motor beyond battery range, the DC generator is spun up. This might be say 10kW to 15kW for a boat if that size, probably delivering 48V DC.
Unlike a 75hp main engine, it will run at its peak revs and peak efficiency - either delivering all its power direct to the drive, or if excess power diverting to recharge the batteries. Once batteries full can stop the generator for a while till needed again.
Hence why on similar sized tanks the range can be 2-3x further than the pure diesel option, due to increased energy efficiency of the serial hybrid.

As noted, not for all boats and budgets, but for those happily dropping €1-2m on their new yacht it is a credible option. Particularly as many such buyers may already have a Porsche Taycan as their daily runabout.

 

[lustyd]

Why can't you answer a simple question?

I can. I chose not to because you don’t accept answers and instead decide to move the goalposts. You’ve made up your mind despite a thorough lack of current understanding and I won’t engage in such pointless arguments. If you want to know the real range of current electric installs it’s all out there to find and will surprise you. As will the regen capability of current gen oceanvolt installs.

 

[Bouba]

Electric propulsion (in anything) has become the new anchor when it comes to arguments and emotions

 

[lustyd]

Electric propulsion (in anything) has become the new anchor when it comes to arguments and emotions

Indeed, and many will cling to their CQR well into the next century despite all evidence.

 

[lustyd]

None of which are OTS; they look nice, but are not even approaching the commodification of small diesels. Let's have this discussion again in 10 years.

First link on Google searching for diesel hybrid yacht engine. Seems OTS to me. As do the Oceanvolt solutions. Sure you have to do an electric install but it’s not like my Volvo Penta has integrated fuel tanks!
Heat Exchanger Hybrid Propulsion - Marine Propulsion Engines Beta Marine

 

[Tranona]

I can. I chose not to because you don’t accept answers and instead decide to move the goalposts. You’ve made up your mind despite a thorough lack of current understanding and I won’t engage in such pointless arguments. If you want to know the real range of current electric installs it’s all out there to find and will surprise you. As will the regen capability of current gen oceanvolt installs.

OK so I have done that and input the data for my old Bavaria 33 oceanvolt.com/configurator/#components So far up to about £40k before shipping, VAT and installation (say £55k installed). This gives me roughly the same top speed and cruising speed as the Volvo D1 30 which costs around £13k including VAT installed with a 150l fuel tank and a folding propeller. However I only get a range of 50.1 miles (the same as you poo pooed when I suggested this earlier) and a recharge time of 8 hours compared with between 350-400 miles from my diesel which takes about 5 minutes to fill. No regeneration possible because my boat is too slow. If you go up to a typical 12m boat which might have a D2 50 the price rises to over £60k compared with £16k for the Volvo.

Can you explain what I am supposed to be surprised about? How long the waiting list is for such a bargain?

What did surprise me is that they only feature less than 100 private yachts fitted with their systems, Surely there should be more if they are gaining real acceptance in the market place. It is one thing to be technically there in the sense that the product functions and another to be a significant force in the market. As I suggested earlier the product is on the cusp of being viable and using customers for development and proof - just like electric cars 20 years ago. Its two main drawbacks of range and cost simply prevent it from becoming mainstream and it needs the leap in technology such as occurred in the car market to move out of the current limited niche. When somebody designs a boat to be specifically electric powered rather than just re-engine existing designs then you know it might have a future above being a niche.

Not sure you think me having this view is in any way defending the status quo or denying what is happening. The facts speak for themselves. unless of course you know something that I don't - which is what I asked.

 

[lustyd]

The facts speak for themselves

They aren’t facts though, they’re your opinions written out in a lengthy diatribe to support your world view. 50 miles is not even remotely close to the range of an electric yacht these days. You’re suddenly bringing cost into the equation despite that not having been part of the discussion, presumably because you understood your other arguments about range to be incorrect so decided to attack cost instead.
Your diesel tank only takes 5 minutes to fill when you’re at a fuel dock. My original point about range was that if a diesel and a solar electric set off then the diesel will run out but the solar never will, it recharges during the voyage and hence has an infinite range. Mid Pacific Ocean you cannot refill in 5 minutes or 5 hours because there are no fuel docks.

 

[Fr J Hackett]

They aren’t facts though, they’re your opinions written out in a lengthy diatribe to support your world view. 50 miles is not even remotely close to the range of an electric yacht these days. You’re suddenly bringing cost into the equation despite that not having been part of the discussion, presumably because you understood your other arguments about range to be incorrect so decided to attack cost instead.
Your diesel tank only takes 5 minutes to fill when you’re at a fuel dock. My original point about range was that if a diesel and a solar electric set off then the diesel will run out but the solar never will, it recharges during the voyage and hence has an infinite range. Mid Pacific Ocean you cannot refill in 5 minutes or 5 hours because there are no fuel docks.

Your argument has an element of logic in it but there are many yachts with a diesel engine with over 2000 mile capability in the unlikely event of it being needed. Yes there is the Hybrid eacht that will use a gen set to provide the electricity to power the electric motor once the 50 or so mile range of it's initial charge has been used up or it will wait for 6 to 8 hours providing the sun is out to start moving again. However even with your argument that using a generator is more efficient than using a conventional diesel at 70% max load it's still burning fuel and still needs to carry fuel. So given the additional and by no means small additional cost of going electric they are something of an unnecessary complication and compromise because as you say most yachts can manage on 50 miles unless there are conditions of having to motor against current, wind lee shore or others.

 

[The Q]

If you have lot of short journeys under power then electric is ideal, for long journeys diesel is ideal.

I've converted my motorboat to electric power, but with a generator. The many trips to clubhouse from mooring, or up to our nearest broad towing my sailing boat I used pure electric, recharged by the solar panels.
For long journeys the generator is wound up to power in parallel with the batteries.

Yes to power with the generator. Is less efficient than by direct diesel , but for me that is more than compensated for by all the shorter journeys powered by pure electric solar power.

Electric motor, batteries, fuel tank and generator all fit in the engine compartment .

It also means everything is gradually going all electric, no gas for cooking.

 

[Bouba]

Your argument has an element of logic in it but there are many yachts with a diesel engine with over 2000 mile capability in the unlikely event of it being needed. Yes there is the Hybrid eacht that will use a gen set to provide the electricity to power the electric motor once the 50 or so mile range of it's initial charge has been used up or it will wait for 6 to 8 hours providing the sun is out to start moving again. However even with your argument that using a generator is more efficient than using a conventional diesel at 70% max load it's still burning fuel and still needs to carry fuel. So given the additional and by no means small additional cost of going electric they are something of an unnecessary complication and compromise because as you say most yachts can manage on 50 miles unless there are conditions of having to motor against current, wind lee shore or others.

In fact many cruise liners and warships are powered like that...electric motors powered by generator

 

[Tranona]

They aren’t facts though, they’re your opinions written out in a lengthy diatribe to support your world view. 50 miles is not even remotely close to the range of an electric yacht these days. You’re suddenly bringing cost into the equation despite that not having been part of the discussion, presumably because you understood your other arguments about range to be incorrect so decided to attack cost instead.
Your diesel tank only takes 5 minutes to fill when you’re at a fuel dock. My original point about range was that if a diesel and a solar electric set off then the diesel will run out but the solar never will, it recharges during the voyage and hence has an infinite range. Mid Pacific Ocean you cannot refill in 5 minutes or 5 hours because there are no fuel docks.

I posted a link to the Oceanvolt website which showed exactly what I was saying. The range is limited to the sort of low figures I suggested.

I appreciate that you are talking about a very narrow range of circumstances - yes you can possibly get a series of 50 mile ranges from the energy harvested from sun and regeneration but in reality how many people actually need or value this? Look at the title of the thread. Electric is not an "equivalent" to diesel for powering sailing yachts. It is an alternative, has been around for years with its own set of characteristics and constraints.

All I have said is that the current developments do make it it more viable for a wider range of applications, but it is still very restrictive and only appeal to a very small number of people. The link illustrates this perfectly. I don't know how many boats have been fitted with Oceanvolt systems, but even if it is 10 times the wide range of boats they feature in their advertising it is still a tiny niche. I added the cost because they are up front about it and it only emphasises how far the product is away from anything approaching a viable mass market.

The current status in terms of performance and cost are facts as is the small number of units in use. The only opinion is about whether this is likely to change in the future and my opinion is that until the issue of energy density storage is resolved the constraints that limit its market acceptability will remain. This in turn will only come about as a spinoff from automotive development and the view from that industry is that the current dominant battery technology will be in place for another 8-10 years before the next leap takes place.

So you can prattle on about the specific set of circumstances where electric has an advantage - I have never questioned this. In the analogy I used earlier that is not dissimilar from the original Lotus based Tesla (and other prototype vehicles from big manufacturers) which demonstrated that a functioning electric car was possible, and indeed superior for a narrow set of circumstances. It took 20 years and legislation forcing development to get to the stage we are at now where just about all car makers have electric powered models selling at a typical price premium of 30% compared with IC equivalents.

My opinion is that this will never happen for sailing yachts while there is a ready supply of small diesels from the industrial market and there is no indication that will change in the future.

 

[Tranona]

In fact many cruise liners and warships are powered like that...electric motors powered by generator

The driver for that is different, at least for cruise ships. For them propulsion is a small part of their power requirements. They are effectively small towns where all services are electrically powered from oil fired generators. Makes sense to then use the same power for propulsion. spin off is that the propulsion units are then outside the hull and can be made steerable. Many ferries are built like this which has the bonus of making them effectively self docking.

 

[Trident]

Yes a sonic which was installed about 5 or 6 years ago when the original sonic was showing signs of wear. I am happy to learn that the 3hm35 was considered a good engine. And yes to Supertramp 6,303 hours running time means good maintenance. So I am hopefull with such positive replies. I may even make the effort to drop my usual doom and gloom negative posts and be more positive. Makes for a happy thread. I will give it a go anyway.

Getting RCD approval may be easier with a change to electric motor with no emmisions. )

I would, if it turns out a new engine is needed, recommend a 3YM30 for the Prout - meets modern RCD if required, lighter and more fuel efficient and will mate with what you have easily. There is also a hybrid engine set up designed for the Snowgoose 37 by Hybrid Marine on the Isle of Wight if you wanted to have diesel and electric in one. Odds are your existing one is still good though.

Its good that the Sonic drive is more recent as they have stopped supporting parts, which means new propriety stuff will no longer be made (like a new yoke if it cracks) so its worth contacting Glen at Sillette and getting some spares for common issues to keep for future use.

As of today nobody has gone all electric on a Prout AFAIK - all of the above comments apply on range, battery weight etc but add to this inefficient hulls on the Elite with lots of drag and a small footprint for a cat, limiting the amount of solar and its really a non starter.

I recently added an extra 1000w of solar to the 1500w a similar sized new cat had for its owner who had spent over £80k on going all electric (including a diesel back up generator) and built a new solar arch that added a meter to LOA to get these extra panels on to try and have a workable range before the generator kicked in (it went from a bout 4 hours to 6) and that was a top of the range install, with money no object. It also sat 4-5 inches lower than an identical boat with diesel so more drag, less efficiency etc.

People tend to forget that you can be very green still with a diesel - just sail as much as possible and only motor when absolutely necessary . In Snowgoose 35 in the Med we used €22 of diesel in an entire season by sailing all the time even if that meant 3 knots under spinnaker in light winds.

There is a very helpful Prout owners group on Facebook by the way with lots of useful information and several hundred experienced owners

 

[BurnitBlue]

Trident. Thanks for the information in your post. I discardid the electric idea because of range and speed. A few posters alluded to the fact that range can be exiended by slowing down to 3 knots. This seemed OK until I realised that there are restrictions on many situations around the world where a mandatory minimum speed is enforced. The Panama Canal for instance which an all day transit at 6 knots would be impossible without special arrangements. Corinth Canal in Greece is avoidable but also subject to minimum speed. I have come across other places with minimum speeds but most are debatable and avoidable. But a hassle.

I will look at the facebook prout owners group. In the meantime my fingers are crossed that the Yanmar 3hm35 will be funcional. I am taking my time after seeing the state of the fuel tank. So a big clean out from tank to injectors. Then the moment of truth when I press the starter button.

 

[lustyd]

However even with your argument that using a generator is more efficient than using a conventional diesel at 70% max load

I never said anything of the sort

 

[lustyd]

The range is limited to the sort of low figures I suggested

No, it isn't. If you don't understand that then fair enough, ask for help. I looked at the site and dropping speed by half a knot doubles range, and these are numbers they guarantee and don't want to be sued over.

 

[lustyd]

People tend to forget that you can be very green still with a diesel

To be fair though, as with cars emissions are only one of the advantages. Removing a working diesel engine is a terrible action for the planet given the energy and materials being wasted. Cleaner, fewer maintenance items, more torque (helps in chop), considerably quieter, zero chance of diesel bug, no carcinogenic inputs or outputs. They might be a challenge for the weekend cruiser right now, but electric definitely has a raft of advantages other than emissions

 

[Trident]

To be fair though, as with cars emissions are only one of the advantages. Removing a working diesel engine is a terrible action for the planet given the energy and materials being wasted. Cleaner, fewer maintenance items, more torque (helps in chop), considerably quieter, zero chance of diesel bug, no carcinogenic inputs or outputs. They might be a challenge for the weekend cruiser right now, but electric definitely has a raft of advantages other than emissions

Electric has many advantages but then again so does a diesel - on the rare occasions we start ours its great to get a free tank of hot water and if need be battery charging too (though we've not actually need to do that yet as solar and lithium powers all our needs including cooking ad we've never needed to use the DCDC charger off the engine but nice to know we can)

I did a lot of research for my boat as I wanted to go electric propulsion but I just couldn't make it work (at any cost) for a round the world cruising boat. To have enough power to get through emergencies or even just to use Panama would need too much weight in batteries and (for the above where you can't sail and have to maintain a minimum speed) a generator so that under sail the boat - in my case a 50 foot fast catamaran - would sail like a dog. Horses for courses but right now electric is limited in applications for most but the pioneers are very vocal and things will only get better

 

[Tranona]

No, it isn't. If you don't understand that then fair enough, ask for help. I looked at the site and dropping speed by half a knot doubles range, and these are numbers they guarantee and don't want to be sued over.

I can see that because I understand the principles of speed and energy consumption. Don't need any help. The more you try to reduce energy consumption to achieve range the more "uncompetitive" electric comes compared with diesel. You can increase the range of diesel in exactly the same way by reducing speed. The cruising speed is quoted at 5.1knots for a range of approx 50 miles with the standard battery pack. If your figure is correct that dropping speed by 0.5 doubles the range (not sure that is correct) then increasing by 0.5 knots to bring it up to the "normal" cruising speed of my Bavaria will halve it to 25 miles. Incidentally I know the range of my Bavarias as I motored almost 1000 miles across the Med in 2010. Their estimates (not guarantees!) are nothing to do with avoiding being sued, but stating energy consumption at an acceptable cruising speed close to what would be normal for a diesel engined boat of that size and type. Real life energy usage when contending with even modest wind and waves will be lower. You cannot ignore the limited energy storage of current batteries. In real life the usable range will be far less than the theoretical estimates just as it is with electric cars.

I am not sure why you seem to ignore well established facts and claim that they are not correct without providing any evidence to support your claims. You create a very specific narrow set of conditions to try and "prove" greater "range" that is far removed from reality. Even if that sort of scenario is believable, experienced people like Trident here who is faced with something close rejects it as impractical at any cost (his words).