Oceanvolt Hybrid Motor

[Redreuben]

Dan, days and days would be an issue, but consider you can't refill diesel tanks at sea but you can top up batteries, further I think occasions where you have to refill and go would be rare. Overnight from empty would have to be a goal at least.

[Cap Erict3]

Originally Posted by Cotemar

Tesla is so successful because they are using 300+ volt 3-Phase 4-Pole AC Induction Motors.

A 48 volt Oceanvolt Motor is just a toy at the moment.

Once Oceanvolt gets up to 240 volts AC induction, they will get out of BETA testing stage.

Baldor is a better source for VFD duty motors.

[beiland]

A posting of mine from another forum....

Originally Posted by brian eiland, post: 171905, member: 782

Don't Throw out the Baby with the Bath Water

This diesel-electric subject thread has certainly raised some lively and controversial discussions. Many want to claim that converting diesel engine mechanical power into electricity, and then back into mechanical power by an electric propulsion motor, just isn't economically feasible. Therefore chuck the whole idea aside when contemplating DE propulsion systems for boats.

I say don't 'thrown out the baby with the bathwater'. This technology is still in its infancy, and there are many more developments to explore....and some may come with other emerging technologies.

One of these new technologies will likely be the ever-increasing capabilities to store electrical energy....new 'batteries', or other such devices and mediums. This capability to store large amounts of electric energy is a technology we sorely need for our future in all sorts of endeavors, and I'm sure there are presently 100's of experimenters around the world working on this major technology.

I agree Innamore. For a strictly powerboat application that spends a small amount of time idling about or maneuvering at docks, etc, and subsequently mostly at speed on the open water, D-E does NOT make sense.....too many energy conversions between main motor and the prop. Thus many powerboats are not applicable DE candidates.

But one thing those DE systems do is break the mechanical link between the engine and the prop. This opens up a whole lot of possibilities for locating the main engines apart from the drive-props, and even the variety of prop-drives that might be employed.

For vessels with big house loads, a DE systems approach makes sense, as well illustrated by the big cruise ships.

Special maneuvering desires can be accommodated with DE systems. A diesel electric system can be shifted from fwd to reverse and back much more quickly than a conventional transmission. In addition the electric motors develop full torque at any speed, even down to 0 rpm. In conventional propulsion installations, the idle speed of the engine will be between 700-1000 rpms. With a typical displacement hull reduction-gear ratio of approx 2.6 to 1, the slowest propeller speed is 270rpm or more. By contrast, a DE propeller shaft can be turned as slowly as 1-rpm!

Furthermore DE systems are much more adaptable to 'steerable prop-drives. Talk about maneuverability!!

If we move beyond ' strictly powerboats', then we might see a use for DE systems aboard wide variety of other type vessels. I'll just give two examples where I wish to use them:

1) Sportfishing Vessels.
Whether pleasure or commercial types, these vessels spend considerable time in the 'trolling mode', usually quite a bit below their cruising speed. This trolling speed might well be accommodated with a DE system.
Gamefishing Catamaran


2) MotorSailing Vessels.
In light airs, running one engine often is all that is needed to bring the apparent wind forward to make the sails work harder, and the combination provides much better results than either motoring or sailing alone…… sailing synergy/harmony, the motor taking over in the lulls and the rig taking over in the puffs

Motorsailing offshore is by far the most pleasant way to make passage, most of the time. With the engine barely above idle and a moderate amount of sail set, there is a synergy created by the apparent wind which generates more forward thrust than either one alone, with the bonus that you don't have to set large areas of canvas, which will have to come down in a hurry if the wind increases. The boat rides better, makes a better average speed and the batteries are always full. The beneft of using a much smaller sailplan can only be appreciated by someone who's been caught offguard in a squall with too much sail up. "Adventures" like that might be fun for weekend sailors and short coastal passagemakers, but on a long ocean passage they're something to avoid, even if it means a slower passage.
Motorsailing Catamaran


3) Etc

[transmitterdan]

There is a fundamental math problem. Bigger and bigger batteries eventually reaches a point of diminishing returns. If one cannot replace the energy in a lot less time than it takes to expend that same amount then bigger batteries are not as useful. And there are no significant improvements in efficiency of electrical systems coming in the future. They are already nearly 80% efficient.

The diesel efficiency of about 50% is also not going to change by anything close to Moore's law.

So the imagined huge efficiency improvements in DE coming "real soon now" are not mathematically possible.

What could be a game changer is not the batteries. Photovoltaic cell efficiency remains in the low 20% range. Which means there is a lot of room to improve that number. Whether that happens or not remains to be seen. But bigger batteries cannot make significant changes in the efficiency of electric propulsion over an extended period of time.

[dlymn]

Beiland I motorsail and I don't see the synergy that you suggest. I'm no fluid dynamics expert, but I reckon that if you're sailing at close to hull speed,for example, having the motor running will make very little difference. I certainly wouln't see any significant reduction of my sail plan just because the motor's running. Having the motor running as you sail, might only reduce prop drag but that can be achieved by having a folding prop. I can't see this as an argument for using electric drive. The only argument that you have given that makes sense is the engine placement for ideal balance but this might be offset by the extra weight of a diesel electric + storage system

[StuM]

Originally Posted by transmitterdan

What could be a game changer is not the batteries. Photovoltaic cell efficiency remains in the low 20% range. Which means there is a lot of room to improve that number. Whether that happens or not remains to be seen. But bigger batteries cannot make significant changes in the efficiency of electric propulsion over an extended period of time.

There may not be as much gain there as you think. There is a thing called the Shockley–Queisser limit to consider.

And even if you get solar cells to be 100% efficient, the problems of sunlight hours, angles of incidence, shading and available space on the average sailing vessel all limit how much solar energy you could realistically capture in a day.

And most of that energy captured still needs to be banked for when the sun isn't shining, so storage is the critical factor.

There are some promising technologies under investigation which may eventually provide high density electrical storage, but I sincerely doubt that we will see then in a commercially viable form suitable for cruising in Redreuben's 5 years. Maybe 20-30 if we are lucky?

[beiland]

Originally Posted by dlymn

Beiland I motorsail and I don't see the synergy that you suggest. I'm no fluid dynamics expert, but I reckon that if you're sailing at close to hull speed,for example, having the motor running will make very little difference. I certainly wouln't see any significant reduction of my sail plan just because the motor's running. Having the motor running as you sail, might only reduce prop drag but that can be achieved by having a folding prop. I can't see this as an argument for using electric drive. The only argument that you have given that makes sense is the engine placement for ideal balance but this might be offset by the extra weight of a diesel electric + storage system

The synergy is NOT going to exist if you are all ready at hull speed. And you have no need of the motor if you are at hull speed.
The real advantage is in those lower sailing speeds where there are many little lulls in the wind, and multihulls in particular lacking the momentum to carry themselves thru the lulls at a constant speed , benefit from the motor making up the difference.

Maybe have a look here:

Is a Motorsailer The Ideal Combination
Sailing Synergy


On all points of sail, the synergy between motoring and sailing produces a net gain in speed over what would be possible with either alone. The speed gain is in fact greater than one would expect. When motor-sailing, 3 knots worth of fuel gets you 7 to 10 knots of boat speed...!

Naturally there must be optimization of the sailing course, since in this mode you are operating primarily as a sailing vessel, with motor assist, and the heading must be suitable for sailing. And of course when under sail alone there is zero fuel use. At today's fuel prices, that is saying something...!
The sailing rig must be set up to be easily handled. Once that's accomplished, the sails will not be any more hassle to handle than paravanes... If the hull shape is designed for maximum efficiency rather than just simply to enclose an enormous volume for accommodations, she will also be a real blast to sail!
When motor sailing to windward or on a reach, the sail rig accomplishes roll reduction, produces a big gain in comfort, and provides a very welcome gain in speed and efficiency. On a reach or off the wind, there is little need for the engine.

******************************************

or here:
MotorSailing Synergy

Originally Posted by Bob Leask

Motorsailing offshore is by far the most pleasant way to make passage, most of the time. With the engine barely above idle and a moderate amount of sail set, there is a synergy created by the apparent wind which generates more forward thrust than either one alone, with the bonus that you don't have to set large areas of canvas, which will have to come down in a hurry if the wind increases. The boat rides better, makes a better average speed and the batteries are always full. The beneft of using a much smaller sailplan can only be appreciated by someone who's been caught offguard in a squall with too much sail up. "Adventures" like that might be fun for weekend sailors and short coastal passagemakers, but on a long ocean passage they're something to avoid, even if it means a slower passage.

I was making this same point in my posting on another subject thread,
"In light airs, running one engine often is all that is needed to bring the apparent wind forward to make the sails work harder, and the combination provides much better results than either motoring or sailing alone…… sailing synergy/harmony, the motor taking over in the lulls and the rig taking over in the puffs"

[44'cruisingcat]

SO carry less sail than the conditions merit, and run an engine to make up the shortfall? Sounds nuts to me. I'd rather sail. (Generally) I'll motorsail is when there simply isn't enough breeze to sail.

[beiland]

Originally Posted by 44'cruisingcat

SO carry less sail than the conditions merit, and run an engine to make up the shortfall? Sounds nuts to me. I'd rather sail. (Generally) I'll motorsail is when there simply isn't enough breeze to sail.

There are those times when one might carry less sail than the conditions might permit:
1) Very gusty conditions with volatile wind strengths. It can pay to cut down the hoisted sail area to something more 'average' in size for safety reasons or when short handed.
2) Reduced sail area for overnight times.

Those are just 2 conditions where someone might be sailing with less than full sail potential. Motorsailing can be a consideration in those times.

[44'cruisingcat]

Reducing sail in situation 1 IS carrying the appropriate amount of sail.


I reduce sail at night to reduce speed. Starting an engine would be counter productive.

[dlymn]

beiland, are you suggesting that I should pull out my diesel engine and install a diesel electric system plus batteries so that I can reduce sail area on those occasions when the wind is light and blowing in a particular direction? So my current setup is fine when I'm motoring, my sails are fine when the wind is up, but I should spend a hundred grand to reduce the risk of rounding up in light winds(what is the risky thing about light wind sailing and why won't the standard diesel/sail combination solve it)

[dlymn]

Beiland, I motor sail when the wind is not what was forecast We lift the sails and if they can't generate enogh power to get me to the next port within the time frame I had planned I start the motor. I always start by lifting the sails. We leave the sails up while they still can hold shape. We think that they might contribute 1/2 to 1 knot. We think that the sails might reduce roll acting like a shock absorber. The moment the sails lose shape, we drop them. I admit that i am not a wind chaser who is obsessed with wind power only; we decide to go somewhere and we then set about getting there. If we get a few hours sailing, then we're ecstatic. None of that is improved by electric power or diesel electric power. At the moment, the cost of changing over is not outweighed by the performance, comfort and economy benefits

[beiland]

Originally Posted by 44'cruisingcat

Reducing sail in situation 1 IS carrying the appropriate amount of sail.

So you always know the appropriate amount of sail you can carry in gusty conditions, or more importantly anticipating what unusual weather might be coming? You've never found yourself reducing sail beyond those current existing conditions just as a safety measure??

I sure would like to like to know your forecaster

Perhaps a review of the capsize of 57 catamaran Anna might be informative. If I remember correctly the owner did not feel he was over canvased for the conditions he was sailing in. And then imagine if this capsize had occurred at night.

My point is that often we reduce sail excessively for reasons of safety. but at the same time we are trying to make a destination in a timely manner. One of the solutions can be to augment the smaller sail area with the motor,....MotorSailing.

[beiland]

...just found this other subject thread dealing with the catamaran Anna,...and this interesting excerpt....

Originally Posted by Dragon701

While my family and I spent a year sailing our Atlantic 55 over 8500 miles, I consider myself a beginner on it and catamarans in general. I have sailed Hobies and charter cats a fair bit, but nothing offshore before this one. I have, however, sailed over 100,000 miles in mono-hulls (first Atlantic crossing in 1969).

For me, the old "saw" about setting your sails to the lowest expected wind speed in a mono-hull and to the highest expected wind speed in a catamaran says a lot about the differences in managing the boats. Given that the highest "expected" wind speed is both a guess (or, hopefully, a sound judgment) and without practical limit on the upside, setting the right sails was, for me, more of an uncertainty on a cat than on my mono-hulls. This is another way of saying that, for me, a mono-hull was more forgiving of an error in picking the right sail combination.

A person could increase his or her margin of error for a wind driven capsize (the “forgivingness”) on any catamaran by decreasing the size of its rig and vice versa. Obviously, this is a true statement for a mono-hull too, but, in my opinion, it is a more powerful lever on a catamaran.

On our trip from the Bras d'Or Lakes in Canada direct to Bermuda in September 2009, we chose to leave on the back of a front. Our winds were a steady 30 knots, which meant lulls to 20 and gusts to 40. We were reaching with double reefed main, staysail and the windward board down. The seas were not unusually big for these conditions, but very confused as we came out around Sable Island. The water is shallow (in the macro sense -- 75' to 250') causing the currents to swirl around. I felt very comfortable with this rig. Had the wind increased to over 60 knots in one of the squalls that we experienced, the boat would have handled it fine. I would have headed off some more, eased the main sheet, pulled another reef (which we could do just fine off the wind) and rolled in some staysail. I wouldn't have wanted a single reefed main and staysail up.

That said, I don't believe that Anna was over canvassed beating with one reef and the staysail up in 12 to 20 knots of apparent wind with squalls around (as I interpret his account). Nor do I find it inappropriate that they were on autopilot and in the wheel house.

It is so easy to be the Monday morning quarterback -- I really hesitate. This is just one point of view:

1) We wouldn't have left in these conditions unless for some odd reason we had to. My wife is an atmospheric scientist so we have excellent weather information and analysis. She (we) reviewed the data that we would have had before this trip and I base my comment on this review. Of course, I realize that it is easy for me to make this judgment here and now. This situation was different from the front we left Canada on. Our situation then was more "stable" in a way and we knew we were in for a lot of wind, so we were ready for it. Even with the much lower general wind speeds, I would describe this situation as more "unstable" or perhaps uncertain than ours was.

2) It is impossible to say how we would have reacted to the sky conditions at the time, but assuming that they were same as they had been for the last 24 hours, I might have left the boat in single reef/staysail/autopilot. The Anna folks mentioned that they were "wary." Maybe, we would have done something different. Maybe I would have been in the cockpit, maybe not. Maybe we would have been hand steering. Maybe we would have used the radar to avoid the core of the squall. Maybe we ... well, this is just too speculative for me to form an opinion.

So, assuming that we had stayed set up the way they were:

3) We focus on TRUE wind speed on our catamaran, not apparent, and set our sails based on this and what we expect it to be. This isn't to say that we are unaware of the effect of our boat speed on the wind, which for us has been eye popping with the A55 versus any mono-hull that I have sailed. In the Anna case, they were beating so the true wind was less than the apparent. When the wind gusted and went abeam, however, in our A55 anyway, the boat would have accelerated and the true wind would have been well aft of the beam. In our boat, the true wind would have read higher than the apparent wind, so they were probably already seeing higher winds than the 30 knots that made them jump into the cockpit.

4) Given the above, my first move, before I even left the pilot house, would have been to knock the autopilot down 30 to 40 degrees (three or four pushes of a button). In these specific circumstances with our boat -- e.g. with my sails flattened for beating but the wind coming abeam and increasing -- I would not head up into a squall; I would bear away.

5) Then, I would have eased the main sheet.

6) If was not alone and depending on how the boat was riding, I would take the helm (if my wife was with me, she would have taken it) and the other person would then start cleaning up -- first a reef (or two), then shorten the staysail.

I really love boats, any boats -- power, mono, ship, cats, sail, oars, ice, kayak -- they all have something to offer. The Atlantic 55 was a terrific choice for our family. My wife and I (we sailed about 58,000 miles together during a wandering circumnavigation, plus some, in the early 1980s) are converts to catamarans for our cruising lifestyle. We love the stable platform. In the case of the A55, we love the speed, the space, the forward cockpit, and the pilot house/living room among many other things.

There are characteristics which we don't like too: the A55 has appendages to catch things on (two dagger boards, two sail drives and two rudders). We caught three fishing nets/lines during our one year. I realize that some mono-hulls do too, but they only have one hull to worry about and we have two .

Would I go around Cape Horn in a catamaran (as we did in 1981)? Yes. Would I go into the ice with one (in 1984, we went into ice at over 80 degrees north)? I am not so sure about that -- I would be worried about ice jamming between the hulls.

I have a lot to learn about multi-hulls, but for us, for our long-distance sailing, we won't be going back to a monohull. The Anna Story is a wonderful reminder for me; something to keep me on edge if I ever become complacent.

I am so happy that they were rescued safely and in such a short time. I have spent almost as much time thinking about what they did after they flipped as I have about the cause of it. Lots of lessons learned there too.

Sorry about the long post. Blame Evans and Tom for drawing me in -- I have found their deep experience and thoughtful comments fascinating to read.

[beiland]

Originally Posted by dlymn

beiland, are you suggesting that I should pull out my diesel engine and install a diesel electric system plus batteries so that I can reduce sail area on those occasions when the wind is light and blowing in a particular direction? So my current setup is fine when I'm motoring, my sails are fine when the wind is up, but I should spend a hundred grand to reduce the risk of rounding up in light winds(what is the risky thing about light wind sailing and why won't the standard diesel/sail combination solve it)

I think you are misinterpreting me. I am NOT suggesting that a diesel-electric drive is necessary for motorsailing. It can be just a good old diesel or even gas engine direct drive for motorsailing,....no electrics involved