Oceanvolt Hybrid Motor

[StuM]

Thank you Chris, for a very well reason description based on real world experience!

[beiland]

Originally Posted by transmitterdan

For sure the most efficient system will be a 3-phase AC motor controlled by a variable speed electronic controller. These controllers can and do operate from either DC or AC. The ones that operate from DC are more efficient because to operate from AC they first have to convert AC to DC. So a DC input unit does not have the losses of converting AC to DC.

I don't understand this, but as I've said before my electrical knowledge is extremely poor.

To go back to my original question. Can the generator be made to run enough to supply all of the electrical power required of the propulsion motors?...without the need for big battery banks??

I recognize it might not be the most efficient way to run the boat,...diesel engine running a generator, that in turns provides electrical power for the propulsion motors....at least 2 energy interchanges.

Can the generator/diesel be run at such a variable speed to supply electrical power at either low or high demands?

I thought that this was more of a possibility with DC generators as opposed to AC ones that need to put out a sine-waveform??

I had hopes that these new systems could have two different size generation units (one small, one large) that could cover a whole range of variable outputs for the motor(s).

[BigBeakie]

Originally Posted by Octopus

Where to start?

I've skimmed through this thread and there are so many misconceptions and so much misinformation that I really can't deal with it.

There are people looking through rose-tinted spectacles that insist that black is white and on the other side there are people looking through welder's goggles and insisting that white is black and in the middle there are one or two voices of reason somewhere in the middle on both sides of the debate.

I've owned a Lagoon 420 hybrid diesel-electric catamaran since I bought it from new in August 2007. I've sailed it 15,000 miles with my wife and six chidren, including two Transatlantics.

Diesel-electric propulsion works. Please understand that from my post, if nothing else.

It's as good or better than conventional diesel propulsion in most respects and marginally worse in others. Like all marine matters it's a compromise. Most if not all other Lagoon 420 hybrid owners have converted to conventional diesel propulsion either because they experienced reliability issues caused by an overambitious control system or because the compromise was not right for them.

Diesel-electric boat propulsion is not going to save the planet and is not going to ensure that its rose-tinted proponents ascend to some kind of green heaven. The need to periodically replace the batteries guarantees that it is not green.

I think my hybrid 420 is marginally more fuel-efficient than it's conventionally powered brethren. I don't have any evidence for that statement other than the fact that the single 27hp Kubota engine in the Onan genset seems to push my heavily-laden boat through the water at almost the same speed as the conventionally powered 420s with twin 40hp Yanmars. However, the cost-saving from that fuel-efficiency is probably offset by the cost of periodically replacing the batteries.

With lead-acid batteries, the hybrid set-up is probably heavier than its conventional counterpart. With LiFePO4 batteries, the hybrid set-up is probably marginally lighter than its conventional twin-engined cousin.

The hybrid is far more manoeuvrable than a conventional diesel. I've waited my turn watching a 440 make a complete pigs-ear of berthing in gusty cross-winds and then followed in and parked perfectly. The electric motors connected to their large props have far more grip on the water and I can push through from full ahead to full astern without even pausing in the middle.

I imagine the hybrid is far quieter than conventional diesel propulsion. With the genset off it's eerily quiet and I can barely hear the genset when it's on.

The hybrid is more complex electrically than conventional propulsion, but doesn't have any gearbox and only has one engine where a twin-engined cat will have two of each, or three if it has an auxillary genset as well.

The complexity of the electrics in a marine environment is a concern, but, after seven years, I've had no problems other than a couple of rogue relays and those were both on circuits that a conventional diesel would have.

I only have one engine to service and maintain and a service takes about twenty minutes every 200 engine hours. On the other hand, this also means that I have a single point of failure, as I found out last year when the starter motor failed as I was about to refloat on the rising tide at midnight. Fortunately I had sufficient battery power to get on to a nearby mooring.

The idea of a fossil-fuel-free solar/wind/regen electric propulsion system is a pipe-dream. Propulsion requires serious amount of power that would take weeks or months to collect and would require massive battery banks to take you any significant distance. The eco-damage caused by the periodic manufacture of the batteries would more than outweigh any environmental benefit from saving a few litres of fossil fuel. Solar, wind and regen can do little more than keep your batteries topped up while living on the hook. Not worth the hassle we decided, and we were right.

Sizing a hybrid configuration is far more constraining than conventional propulsion. Not happy with the motoring power of twin 40HP Yanmars? Then upgrade to twin 80HP engines for a little more money. If we wanted to double our available power it would cost a lot, because we would have to upgrade everything, cables, breakers chargers, genset, motors, controls, everything. This is why hybrids tend to be parsimonious with power. We have sufficient for most emergencies, but possibly not all emergencies.

If I was transported back to 2007 then I would still choose a hybrid, as I've enjoyed the ride, but I wouldn't pay to convert a perfectly good conventional diesel to hybrid or vice versa. Starting from scratch I'd probably go hybrid, so long as it wasn't more than about 30% more costly than an equililent conventional diesel set-up. LiFePO4 batteries make hybrids more attractive than they were in 2007.

Chris
Octopus, Lagoon 420 Hybrid, Hull 52
Isle of Arran, Scotland

Thanks Chris!

A very objective assessment from a user, albeit an "older tech" EP installation. Very good feedback though.

Re the role of renewables as a viable energy source, our thinking for planning our system was that there are 2 basic scenarios to be able to handle for offshore cruising and liveaboard. One is the max power for short duration, the "get out of Dodge" emergency like having to pick up the hook in a big blow. We have sized our LFP bank to be able to motor at full power for an hour. The other scenario is the extended motoring situation for getting somewhere when becalmed, or motorsailing into wind like up a passage or fjord and then the DC genset does that admirably.
It seems like a good investment in LFP to get more than you think you may need for the TCO reason that it is then unlikely to need to run them down to 20% DOD very often. This greatly preserves the usable lifetime of the bank, and you then get thousands of charging cycles. The difference here vs LA batts is significant. Especially when considering the huge advances in regen whereby we'll be getting 300% better regen when sailing.

Your thoughts on the above?

[kveebee]

Originally Posted by ranchero76

Even though it's same all over again, I don't mind to repeat my point of view, and actually my point of view slightly changes as more information and options taken in consideration.

First argument - "it can't run for long period of time so you still must start engines/generator". Let see. Everyone says sailing/motoring is just 5% of time, 95% - anchoring or short trips between islands/ports etc.
And then, out of these 5%, how much time in real life sailor spends motoring? I bet not much. Because middle size cat will consume at least 2 gallons of diesel per hour of motoring, bigger - double of that. That's 48 gallons per 24 hours plus associated noise! That's $150 per day! Will get very expensive very quickly. So unless one won the lottery, he will try to not start engines often. Plus - electricity (generator) still needed for water maker, AC (if any), dehumidifier(s), dive compressor, propane needed for cooking, engine started for all these short trips between the islands (as you know almost all the wear engine gets at startups, until oil pressure is developed) etc, etc.

Now my point of view of good hybrid system and it's behavior.
I think it should be parallel setup. Yes, boat will be heavier this way and it probably makes sense only on bigger cats (say, 45' plus, when extra weight not as critical).
Powerful solar setup - must have. Big Li-Po battery bank - must have. Wind generator - I'd say must have. Currently I'm developing system, allowing to mount 7-15 kW of solar array on almost any bigger (45' plus) cat. What it will give you? Unlimited power for everything on the boat even on rainy day, even with partially shaded panels which you can not completely avoid on sailboat (and I'm talking
well equipped boat - with AC, electric stove, big fridge and all other comfort things). And even then, there will be some power for electric propulsion (but most likely still enough for that 95% of time when no long run needed and considered that you've been anchored previous days, your battery bank is full). So virtually, 95% of time boat not using fossil fuel at all. Out of remaining 5%, most likely 4.9% you will be sailing, right? Remaining 0.1% AND emergency situations - that's where you will need your diesel engines (but I'd still rather have this kind of "backup").

Second argument - it's too complicated, it will break, blablabla. Let me guess - you guys, probably afraid to drive modern cars while on hard, because afraid of "very complicated injector engines, data bus control and other modern crap? While it's actually true regarding the car, solar/hybrid system on boat not THAT complicated. Anyone with good electrical knowledge can fix/modify it. But of course, it will scare these who can't repair electric winch or stopped working AC.

Third argument - it's expensive. Well, this is actually correct one. All of described above only makes sense when newer expensive cat purchased, and hybrid conversion, along with solar/wind setup and battery bank will be part of initial investment. But from my point of view - all solar/wind/battery upgrades would be absolutely required anyway, along with repairs and other refit, so cost of installing hybrid drive at that point won't make huge difference. Why would I need such powerful solar setup, 4-6 kW wind generators and huge battery bank? So I can enjoy unlimited AC, unlimited fresh water, unlimited cooking, dehumidifiers to keep things dry and free of rust, unlimited use of dive compressor etc. All of this without starting engine/genset. It's just different point of view, opposite to minimalistic - having minimum comfort, minimum weight (for fastest speed, I guess? But sailing is just 5% of time, remember?) And yes, I know how to fix that stuff when it will break (or if I don't, I will learn, it's that simple).

I like the way you think Ranchero 76

[dlymn]

Originally Posted by StuM

A classic example of why I keep on about using the correct units. You've been misled by not reading this howler more closely: "4kva genset can provide at best 25 kw".

I think you will find that he meant a 4kVA (kW) genset running for the previously stipulated 7 hours would "provide at best 25kWh".

i.e he is assuming a 4kW genset, not a 25kW one.

Still going on about the big H Stu M.
So do your magic on this;
from an actual boat with an OceanVolt SD10 (not even 15kW !) a 12.5m Lwl 3.9m Boa 7,800kg displacemet mono actually, in REALITY no less, as in from an actual boat and EP conversion, goes about 20 nm at 5.5knots using 16kW of battery juice. Ok? That is 8 x 160 Ah Super B batteries.

8 x 12v x 160 AH = 1280 ah. Assuming 100% drain, How long will these batteries operate a 10kw motor assuming full load? My guess is 1.5 hours. Big breakie says a tad under 4 hours.

The only way this could happen is if the 10kw motor was drawing about 4kw. So I should be able to drive an 8 tonne boat at 5 knots using 4kw. Why do I need a big diesel or electric motor when I can do the job with a piddling little outboard motor. Hell I could probably bolt my diesel starter motor to the drive shaft and do away with the engine altogether

[StuM]

Originally Posted by dlymn

So do your magic on this;

Since you ask so nicely:

from an actual boat with an OceanVolt SD10 (not even 15kW !) a 12.5m Lwl 3.9m Boa 7,800kg displacemet mono actually, in REALITY no less, as in from an actual boat and EP conversion, goes about 20 nm at 5.5knots using 16kWh of battery juice. Ok? That is 8 x 160 Ah Super B batteries.

Dont forget the "h"!

20NM @ 5.5 knots = 3.64 hours
If it uses 16kWh over that time, it is drawing 4.4kW or a bit under half the maximum power of the SD10. (That is about 6 HP)

With a nominal voltage of 13.2V for the SuperB, that 16kWh is 1,212Ah
And yes, that would require 8 x 160Ah batteries, weighing 215kg.

Assuming they were at 100% SOC when you started, you would run them down to about 5% SOC. If you have any other power drains over that time, you'd need at least one more.

An appropriate diesel engine would probably use about 11 litres of fuel for the same result ( I need about 14 litres to do the same distance/speed on my boat which is a similar length but a bit heavier).

[Cap Erict3]

Originally Posted by Octopus

--------



I've owned a Lagoon 420 hybrid diesel-electric catamaran since I bought it from new in August 2007. I've sailed it 15,000 miles with my wife and six chidren, including two Transatlantics.



---------

Diesel-electric propulsion works. Please understand that from my post, if nothing else.





Chris

Octopus, Lagoon 420 Hybrid, Hull 52

Isle of Arran, Scotland

It is good to hear an honest evaluation from a long term owner.

EP has been reliably driving boats for many years. So yes, it does work.

Does your system use standard DC motors or motors like OV?

[dlymn]

Ranchero: "I'm developing system, allowing to mount 7-15 kW of solar array on almost any bigger

Ranchero, I have 48 solar panels on the roof of my house. Each one generates 250w. They measure 1.6metres x 1 metre (1.6 square metres). A 15kw array would cover 60 square metres which I guess is why it would be restricted to very large boats. Have you considered how to design a system to withstand gale force winds? Have you reflected on the interaction between this surface and the sails if it was mounted underneath it. When the sails are up, significant areas of the surface might be shaded. If you are considering semi flexibles, these will not take substantial traffic or belts from dropped objects. They are also more inefficient than fixed panels. There are panels that can be attached to sails but this puts them at a steep angle to the sun most of the time and I wonder how they withstand furling in any form..

We are fairly happy with them although I no longer believe the hype about daily energy production. We were told they would produce maximum energy for 5 hours a day, but they forgot to mention that's 1 hour in winter and 12 hours in the height of summer. I guess on snowy areas, the results might be less inspiring.
We are about to add another 5kw so that we improve the likelihood of running our 12 kw A/C for more than a couple of hours free.

We haven't bought batteries because the figure just don't add up. We would need to get them for US$100 per kva @12v. and they would need to last for 4 years before we broke even. At the moment a Tesla battery costs close to 6 time that.

You might be able to use some of this in your planning.

[dlymn]

Originally Posted by StuM

Since you ask so nicely:

from an actual boat with an OceanVolt SD10 (not even 15kW !) a 12.5m Lwl 3.9m Boa 7,800kg displacemet mono actually, in REALITY no less, as in from an actual boat and EP conversion, goes about 20 nm at 5.5knots using 16kWh of battery juice. Ok? That is 8 x 160 Ah Super B batteries.

Dont forget the "h"!

20NM @ 5.5 knots = 3.64 hours
If it uses 16kWh over that time, it is drawing 4.4kW or a bit under half the maximum power of the SD10. (That is about 6 HP)

With a nominal voltage of 13.2V for the SuperB, that 16kWh is 1,212Ah
And yes, that would require 8 x 160Ah batteries, weighing 215kg.

Assuming they were at 100% SOC when you started, you would run them down to about 5% SOC. If you have any other power drains over that time, you'd need at least one more.

An appropriate diesel engine would probably use about 11 litres of fuel for the same result ( I need about 14 litres to do the same distance/speed on my boat which is a similar length but a bit heavier).

Stu, 6hp driving an 8 tonne displacement hull at 5.5 knots. So I can use my dinky tender motor to motor around. Chuck out the 55 hp diesel and add a engine transom on the sugar scoop and go for it, I reckon I might use 6-10 litres of petrol to do that too. Sounds like all those boat builders for all those years have had it all wrong.

I recall being on a Macgregor 26 with a 60 hp outboard on the back. The best we could get out of it with the water ballast in was 8 knots. given that these things probably weigh less than 3 tonnes. I might have been able to get up to the 5.5 knots with a little 2.5 hp Yammie.

Maybe I need all that extra power to bring the boat up to 7.5 knots, to drive into high seas, to motor upwind in 25 knots, to fight 6 knot tides to have full power available at any time and especially in an emergency. We have been looking at and idealised scenario with no consideration for high battery drain, inefficiencies of energy management, environmental factors (wind, waves, current), deviation from a set course to attend an emergency or to look at something over there, battery cost, increased weight, travelling longer distances, energy consumption getting in and out of port etc etc.

[myocean]

Originally Posted by StuM

So who's got the curves for the Oceanvolt SD15? Big Beakie?

You can calculate this from the numbers they provide. Its no magic.

[ranchero76]

Originally Posted by dlymn

Ranchero: "I'm developing system, allowing to mount 7-15 kW of solar array on almost any bigger

Ranchero, I have 48 solar panels on the roof of my house. Each one generates 250w. They measure 1.6metres x 1 metre (1.6 square metres). A 15kw array would cover 60 square metres which I guess is why it would be restricted to very large boats. Have you considered how to design a system to withstand gale force winds? Have you reflected on the interaction between this surface and the sails if it was mounted underneath it. When the sails are up, significant areas of the surface might be shaded. If you are considering semi flexibles, these will not take substantial traffic or belts from dropped objects. They are also more inefficient than fixed panels. There are panels that can be attached to sails but this puts them at a steep angle to the sun most of the time and I wonder how they withstand furling in any form..

We are fairly happy with them although I no longer believe the hype about daily energy production. We were told they would produce maximum energy for 5 hours a day, but they forgot to mention that's 1 hour in winter and 12 hours in the height of summer. I guess on snowy areas, the results might be less inspiring.
We are about to add another 5kw so that we improve the likelihood of running our 12 kw A/C for more than a couple of hours free.

We haven't bought batteries because the figure just don't add up. We would need to get them for US$100 per kva @12v. and they would need to last for 4 years before we broke even. At the moment a Tesla battery costs close to 6 time that.

You might be able to use some of this in your planning.

It's actually quite simple system, side mounting, both sides of catamaran. It's foldable, so can be folded in bad weather. Very light flexible panels on light fiberglass underlayment/reinforcement. Modern flexible panels give about 200W per m2, and can be purchased for way less than Amazon offers:
https://www.amazon.com/HQST-Monocrys.../dp/B017OMTAV6

My drawing shows that 30 m2 of solar panels can be installed on each side (which, again, can be folded), so 60m2 plus another 20 m2 behind flybridge (if needed). Yes, this is for big cats ( I have 55' plus in mind).
Regarding the shade - it can't be avoided on the sailboat. While properly connected, output only will be reduced from these shaded panels, the rest will be fine. That's why such powerful setup needed - in reality output never will reach 15kW unless there will be no sails and directly under the sun.

Plus - couple 1.5kW wind generators, on back flybridge corners, out of reach. Yes, I know they have almost 10ft blade span, but they are not heavy (think about 1.5kW electric motor). Electrical and mechanical brake, and also removable blades will help in bad weather.

For battery bank - I think 40kWh of LiPo batteries would be appropriate.

For propulsion - hybrid, with Tesla S electric motor. It's already hacked, and can be used with third party controllers. Its power is 300kW (over 400hp), so YOU have a choice, run it at 5kW, 50kW or 200kW. Mileage will vary of course

https://www.youtube.com/watch?v=zMQjcukphpA

On good sunny day, there should be few hours of electric motoring, or couple hours of fast motoring (solar+(wind in any direction)+battery). Need more? Either wait (as most sailors at sea do in no wind situations, right?), or start that oily diesel. My guess - diesel never will be started while near the shore (and that's where boat spends most of its life, right?).
On anchorage there will be plenty of power for all appliances and devices onboard, including power hungry as AC, water maker, water heater, big fridges etc. The goal - to have all regular home services without starting the diesel.
Note that this setup is totally different comparing to Lagoon 420.

[Octopus]

Originally Posted by BigBeakie

Thanks Chris!
We have sized our LFP bank to be able to motor at full power for an hour.

An hour is plenty. Twice our genset has failed at critical moments and each time we were safely anchored or moored within ten minutes.

[Octopus]

Originally Posted by BigBeakie

It seems like a good investment in LFP to get more than you think you may need for the TCO reason that it is then unlikely to need to run them down to 20% DOD very often. This greatly preserves the usable lifetime of the bank, and you then get thousands of charging cycles.

Agreed, the benefits of LFP compared with LA are huge and it's worth buying a bit more than you really need to extend their life. There is a weight penalty, but worth it.

[Octopus]

Originally Posted by BigBeakie

Especially when considering the huge advances in regen whereby we'll be getting 300% better regen when sailing.

What are these huge advances in regen? I refuse to believe that regen today is 300% more efficient than it was when my boat was built in 2007. Regen works well on my boat, but I the times that I am prepared to sacrifice the extra knot of speed it costs are few and far between. I only use regen as a form of brake to slow the boat down when we are going a little too fast for comfort (i.e. very rarely).

[StuM]

Originally Posted by dlymn

Stu, 6hp driving an 8 tonne displacement hull at 5.5 knots. So I can use my dinky tender motor to motor around. Chuck out the 55 hp diesel and add a engine transom on the sugar scoop and go for it, I reckon I might use 6-10 litres of petrol to do that too. Sounds like all those boat builders for all those years have had it all wrong.

Nope, they've got it right.

In calm conditions, I can drive my 11 tonnes at 5 knots on one 3JH3 engine at 2200 RPM. That's using about 6HP and 2 lph.

I recall being on a Macgregor 26 with a 60 hp outboard on the back. The best we could get out of it with the water ballast in was 8 knots. given that these things probably weigh less than 3 tonnes. I might have been able to get up to the 5.5 knots with a little 2.5 hp Yammie.

Maybe I need all that extra power to bring the boat up to 7.5 knots, to drive into high seas, to motor upwind in 25 knots, to fight 6 knot tides to have full power available at any time and especially in an emergency.

Exactly!

There have been other situations where I've used a combined 36 HP from both engines running at 3000 RPM burning 9 lph and been glad that I still had a lot of HP in reserve.

That's the part that the small EP proponents don't consider.