Oceanvolt Hybrid Motor

[Cap Erict3]

Originally Posted by flynlion

Has anyone factored in using one of the new vertical mast mounted wind generators, saw one said to put out 800 watt -1KW at 18 knot wind speed.......just saying that maybe one day it will all be practical. Instead of all the negativity, maybe work toward a solution, I mean who wouldn't want to be totally independent?

While there are many here that like the idea of EP sailing vessels, as seen by the number of posts on the subject, it would take positive reviews from owners to inspire me to look at it with more than idle curiosity. I am sure that most feel similarly.

When they build the mouse trap it will market itself with prototypes than can actually perform as touted.

[StuM]

Originally Posted by transmitterdan

Dlynn,

You are maybe confused about the difference between kW (killowatts) and kWh (kilowatt-hours). A 25kW generator running for 7 hours can produce 175kWh of energy. Therefore a 16kW motor powered by such a generator needs no battery at all.

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.

[StuM]

Originally Posted by dlymn

I see what you're doing there. Noone is talking about 25 kw generators. A16kw engine require the equivalent of 16 kw of energy to operate for one hour. If it works for 7 hours it consumes a total equivalent of 112 kw, I don't care whether it has an h on the end or not, the batteries still have to provide 112 kw of energy; all the readers know that's equivalent to 112 kw for one hour or 16 kw per hour for 7 hours.

Puhlease! We do care whether it has an h on the end or not. Using the wrong units makes posts much more difficult to understand and frequently results in incorrect answers.

Take a break, go and read this:

http://www.cruisersforum.com/forums/...ml#post1933764

Then come back here and talk sensible units.

[StuM]

Originally Posted by flynlion

Has anyone factored in using one of the new vertical mast mounted wind generators, saw one said to put out 800 watt -1KW at 18 knot wind speed.......just saying that maybe one day it will all be practical. Instead of all the negativity, maybe work toward a solution, I mean who wouldn't want to be totally independent?

There are quite a few "1kW" vertical windmill on the market. I've never seen one that is practical to install on a reasonable sized cruising boat. Have you looked at the size of those things?

[StuM]

Originally Posted by leftbrainstuff

Can anyone post valid power and torque curves?

Only for ic engines. EP suppliers seem very reluctant to provide any real figures other than their marketing hype.

Can anyone state the test configurations so that we can compare apples to apples?

Same answer as above.

[myocean]

Originally Posted by leftbrainstuff

Can anyone post valid power and torque curves?

Thank you for getting back to rational discussions.
I think the data available for diesel engines, e.g. form Volvo is very good. E.g. one of the main specifications is Propellor Shaft Power and the diagrams for torque and power at calculated propellor load are very well suitable.
For most electric drives the torque curves are more or less just flat. No magic.

[BigBeakie]

Originally Posted by valhalla360

Again, when you get this boat with magical electric HP, please provide some data. If it's half as good as you claim, diesel engines will be gone within 5yrs. Of course, I'm beginning to think you are affiliated with oceanvolt as you are defending it far beyond what a casual guy interested in the tech would. Given the outright lies in some of their marketing material, I wouldn't put it past them to post under a false name.

Well I just have to respond to this crap Your accusation towards OceanVolt shows you for what you are!

No, I have no affiliation with OceanVolt or any other marine company whatsoever. To be specific for you, I have no pecuniary interest, meaning I make no money whatsoever from anyone in the marine industry.

I do however spend alot of money in the marine industry lately as we are building a 50' cat & for full disclosure for your Lordship Valhalla, I intend to be a client/customer/user of OceanVolt.

FYI, Lord Valhalla, I issued an RFI to all the betterr EP vendors I could find and I received some good responses and some not so good responses and I short listed based on the information I received back to the RFI. OceanVolt were,by far, the most credible of the vendors & that credibility was increased as I entered into discussion with them, and then checked customer references. Then I actually went on some OceanVolt installations and had great talks with those owners about their experience & why they chose OceanVolt.

You got the full picture now?

As far as I'm concerned, you owe OceanVolt an apology on this forum for your slander, and you owe me an apology for your paranoid accusation.

[BigBeakie]

Please publish contact details of the people who are using this system so that we can contact them personally

dylmn,

You MUST be kidding!

Please first publish your real name so OceanVolt know who the troll is who is trying to hassle their clients.

[leftbrainstuff]

Originally Posted by StuM

There are quite a few "1kW" vertical windmill on the market. I've never seen one that is practical to install on a reasonable sized cruising boat. Have you looked at the size of those things?

Pound for pound and dollar for dollar vertical turbines are a highly constrained design. Heavy rotating elements tend to make them less effective compared to many of the horizontal axis options.

Guido sailing eventually removed his vertical wind turbine in his youtube series

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[leftbrainstuff]

Originally Posted by StuM

Only for ic engines. EP suppliers seem very reluctant to provide any real figures other than their marketing hype.

Same answer as above.

Curves for electric motors are also readily available. Most of the advancements have been in power controllers in recent years.

Perhaps someone will run some back to back dyno tests and give us some good data to mull over.

We need motor only data and full system hydrodynamic data.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[myocean]

Originally Posted by StuM

Only for ic engines. EP suppliers seem very reluctant to provide any real figures other than their marketing hype.

Torque curves of electric motors are just not as mysterious and individual as diesel curves. So one could say they are more boring: Electric motors provide full torque over a wide rpm range until the maximum power is reached. In many cases, if the system permits higher rpms, the torque would decrease from that point on.
Here the torque curve of a Torqeedo Deep Blue 25 kW shaft drive motor. (dotted line is short time peak torque only)

[leftbrainstuff]

Originally Posted by myocean

Torque curves of electric motors are just not as mysterious and individual as diesel curves. So one could say they are more boring: Electric motors provide full torque over a wide rpm range until the maximum power is reached. In many cases, if the system permits higher rpms, the torque would decrease from that point on.
Here the torque curve of a Torqeedo 25 kW shaft drive motor. (dotted line is peak torque for short time only)

Attachment 137102

And if we compare to a diesel pv and torque speed data you'll see the difference and why comparing a single data point is pointless.

Electric motors that are torquey are low speed. IC engines are very basically the opposite. Particularly the more modern high speed diesels. Hence the fuel efficiency of diesels which are fuel regulated IC engines.

You need to include complex electric power controllers to make an electric motor flexible in terms of rpm. Variable pitch props become very necessary with electric propulsion unless you want to add a transmission.

To normalize we need to look at measures like thrust curves, cost / distance, energy consumed / distance. Embodied cost or full lifecycle cost.

New for new the costs will be closer.

My original motorsport mentor stated it well. 'Horsepower wins pi##ing contests and torque and drivability win races'. And 'when the flag drops the bs stops.'

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[myocean]

Originally Posted by leftbrainstuff

You need to include complex electric power controllers to make an electric motor flexible in terms of rpm. Variable pitch props become very necessary with electric propulsion unless you want to add a transmission.

With todays state of the art power electronics this is not the case anymore.
Variable voltage and variable frequency operation is nothing special anymore. Consequently you can as well forget about a requirement for variable pitch props. (Nevertheless this is always nice to have, same as for a diesel)

[StuM]

Originally Posted by leftbrainstuff

Curves for electric motors are also readily available. Most of the advancements have been in power controllers in recent years.

Perhaps someone will run some back to back dyno tests and give us some good data to mull over.

We need motor only data and full system hydrodynamic data.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

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

[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