SailNet Community

SailNet Community (http://www.sailnet.com/forums/)
-   Gear & Maintenance (http://www.sailnet.com/forums/gear-maintenance/)
-   -   Diesel-electric hybrid (http://www.sailnet.com/forums/gear-maintenance/84071-diesel-electric-hybrid.html)

deckofficer 02-19-2012 03:43 AM

Diesel-electric hybrid
 
Searching for you folks that have already converted to diesel electric. My plans are for a 48 volt propulsion/house bank, 48 volt inverter, and diesel DC gen set. I am comfortable with electrics, have designed, built, and raced EVs.

Rockter 02-19-2012 04:19 AM

Unless you are planning to run submerged, I would not bother.

Every time you change energy from one form to another, you will suffer losses. Batteries, particularly lead-acid accumulators, are notoriously innefficient at storing energy, and recovering it again.

Diesel-electrics are often seen on rail locomotives, largely because of coupling issues as it is so difficult to get drive to multiple wheels with mechanical drive.

But on a sailboat??? Your diesel engine will give you about 40+% efficiency, and the tank fuel will take you far further than the most massive of battery banks, battery banks that slowly lose poke as they are cycled.

And what size of generator are you going to need for (say) 35 hp at the prop?

I warn you too, with seawater-wet hands, 48 V will make life very exciting for you. It is exciting enough with nominal 12 V. Try it.
.

LakeSuperiorGeezer 02-19-2012 08:58 AM

50 volts can be lethal

deckofficer 02-19-2012 12:11 PM

The displacement at cruise weight will only be 8500~9000 lbs, so electric propulsion will only need to be in the 8~12Kw range. I hope to not even use the diesel much, but as a cruiser I want the option of running from a storm for days, not hours. The diesel gen set will output DC for charging only, because it would be much heavier (and redundant) for it to be a typical 120/240 VAC 60 Hertz unit when a 48 volt input inverter is part of the system. A hybrid system such as this has a lot of advantages.

1) weight placement flexible for better balance and trim
2) The low rpm torque capabilities of an electric motor for tight quarter maneuvering is sweet.
3) The weight is an even wash with the components I've sourced.
4) I've always wanted a fully electric galley, from the induction cook top all the way to the 1500 watt rail mounted BBQ.
5) Even the dinghy will be electric, never have been a fan of gasoline and propane.
6) I have a personal reason too, the DC diesel gen set can be fueled with renewable fuels, and after working in the oil industry, I have a strong disdain for them and their product.

So, I'm doing it, no need to try and talk me out of it. Is there anyone on the forum who has also converted over to diesel-electric hybrid drive?

knothead 02-19-2012 12:23 PM

Quote:

Originally Posted by deckofficer (Post 833683)
The displacement at cruise weight will only be 8500~9000 lbs, so electric propulsion will only need to be in the 8~12Kw range. I hope to not even use the diesel much, but as a cruiser I want the option of running from a storm for days, not hours. The diesel gen set will output DC for charging only, because it would be much heavier (and redundant) for it to be a typical 120/240 VAC 60 Hertz unit when a 48 volt input inverter is part of the system. A hybrid system such as this has a lot of advantages.

1) weight placement flexible for better balance and trim
2) The low rpm torque capabilities of an electric motor for tight quarter maneuvering is sweet.
3) The weight is an even wash with the components I've sourced.
4) I've always wanted a fully electric galley, from the induction cook top all the way to the 1500 watt rail mounted BBQ.
5) Even the dinghy will be electric, never have been a fan of gasoline and propane.
6) I have a personal reason too, the DC diesel gen set can be fueled with renewable fuels, and after working in the oil industry, I have a strong disdain for them and their product.

So, I'm doing it, no need to try and talk me out of it. Is there anyone on the forum who has also converted over to diesel-electric hybrid drive?

That's a good point. The ability to heat water, power winches, make water, heck even use an electric blanket. All while carrying only one kind of fuel.
I would definitely sacrifice a little power to be able to have the convenience of all the extras.
Plus, I bet it would be a lot easier and less trouble to maintain or replace a small generator rather than an inboard diesel.

deckofficer 02-19-2012 12:35 PM

It would still be a single inboard diesel, but instead of a 500+ lb hunk of iron to produce 14Kw AC, it would be less than 300 lbs for the same output at DC charging voltages.

robmo 02-19-2012 01:18 PM

Hey deckofficer, I've been around boats for 40 years and reading about the system that you are describing, it seems to me that you will be in a world of hurt in the short run. When it comes to boats I firmly believe in the KISS method. You're sitting in a fiberglass tub surrounded by saltwater and its always humid with a fog of salt. When it comes to boats Murphy was absolutely right. What's more if you're in a sailboat, sail the damned thing, that's how you get better at it. Installing complicated systems in a boat takes you away from what you should be doing with it.....sailing. I owned a J24 for nine years and I think we used the kicker three times and then only because we had to.

Anyway, good luck with all that....I think you'll need it.

chef2sail 02-19-2012 01:25 PM

I am intrigued and would lovbe to find an alternative propulsion system. One of my friends is interested in converting also to a mastervolt system similar to what you are describing.

So a generator and the large battery bank only weighs 300 lbs? Explain how you come up with that figure?

Dave

deckofficer 02-19-2012 01:30 PM

Quote:

Originally Posted by robmo (Post 833714)
Hey deckofficer, I've been around boats for 40 years and reading about the system that you are describing, it seems to me that you will be in a world of hurt in the short run. When it comes to boats I firmly believe in the KISS method. You're sitting in a fiberglass tub surrounded by saltwater and its always humid with a fog of salt. When it comes to boats Murphy was absolutely right. What's more if you're in a sailboat, sail the damned thing, that's how you get better at it. Installing complicated systems in a boat takes you away from what you should be doing with it.....sailing. I owned a J24 for nine years and I think we used the kicker three times and then only because we had to.

Anyway, good luck with all that....I think you'll need it.

I'd much rather sail too. The systems are not complicated, just different. This is for a PDQ 36, that isn't the LRC, but lets say it is the LRC. (3) diesels, (2) for propulsion when needed, and all the through hulls for that, one for running high wattage AC appliances at 120/240 60 cycle. All I am doing by going with the non LRC model is swapping (2) Yamaha 9.9 gasser outboards with electric outboards, and instead of having a heavy gen set for AC, going to a much lighter gen set for DC only to charge the propulsion/house batteries as they need it. I hope to not even run the DC gen set much, with solar panels and regen from either motor if left in the down position while under sail.

robmo 02-19-2012 01:41 PM

You wrote "running high wattage AC appliances at 120/240 60 cycle"

Whoa, so what you're telling me is that you're sailing a condominium, Hmmmmmm. I guess my general advice is falling on deaf ears. I once knew some folks who owned a Bristol 36 with all the bells and whistles...hell, I think the thing even sported a trash compactor. Anyway, they loved that boat until it started to s_it the bed on a regular basis and they spent many a beautiful weekend tied to the dock trying to fix the trash compactor or whatever, rather than sail. They never did learn how to sail that damned thing.

Bon chance, my friend.


All times are GMT -4. The time now is 09:40 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012