Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 12-07-2009, 20:06   #16
Registered User

Join Date: Feb 2008
Posts: 2,061
Just to carry this a bit further, let's assume you want a genset that will sustain propulsion, and electric motors that are less than half the power of the MD-22p I mentioned. Assume you don't expect the batteries to sustain electric power beyond a few miles, so you use the smallest GRP-24 batteries (about 60 lb. each). If you need at least 60 volts you need a minimum of 300 lbs of extra batteries, plus your house bank, genset start battery, genset and drive motors.

Adding all that extra weight on a multihull is like giving sugar to a diabetic.

And what do you accomplish?
__________________

__________________
SailFastTri is offline   Reply With Quote
Old 13-07-2009, 00:04   #17
Long Range Cruiser
 
MarkJ's Avatar

Cruisers Forum Supporter

Join Date: Dec 2007
Location: Australian living on "Sea Life" currently in England.
Boat: Beneteau 393 "Sea Life"
Posts: 12,828
Images: 25

Quote:
Originally Posted by SailFastTri View Post
  1. complexity
  2. with more complexity comes less reliability


We are with 130 boats ready to start a rally through Indonesia. All the boats have come up the East coast of Australia (OK some others my have parachuted in)... Of all the boats who have problems, or who have had problems, fall into 2 categories: Old crap-lockers or Complex systems.

We are sitting around chewing the fat waiting for the start because NONE of our systems have broken down. None of our systems are complex, and the boat is only 8 years old.

So if you are buying a boat, believe me, get well away from complex or old systems.

Complex systems:

Generators,
wind generators (bearings/noise),
freezers (there is ALWAYS someone with a bung freezer trying to transfer melting meat!),
snazzy props that fold, feather but really just deflate,
Dinks with 4 stroke OBs or 'fixed' carbs to increase HP,
Weirdo engines (especially old ones - not engine hours just old!)

and of course the biggie: WATERMAKERS!!!!!!!!!

Go SIMPLY! and you will GO Have complex and you will be stuck in port sweating and yelling.

The Hybid elec engine on one of the newer cats was stopped after a years production because someone realized its a technological nightmare.


Hope this gives you my opinion unequivocally


Mark
__________________

__________________
Notes on a Circumnavigation.
OurLifeAtSea.com

Somalia Pirates and our Convoy
MarkJ is offline   Reply With Quote
Old 13-07-2009, 06:18   #18
Registered User
 
Rising Star's Avatar

Join Date: Jun 2009
Location: aboard
Boat: Freedom 32
Posts: 65
Putting the word electric anywhere near the word propulsion seems to cause blood pressure increases. Since I actually have an electric system in operation perhaps I can address some issues from the the real world. Because I don't know what system Peter will use I will use my own as a basis for rebuttal.

Simple answer:
  1. weight (we could stop here)
  2. price
  3. complexity
  4. with more complexity comes less reliability
Weight - My system of motor, 8 AGM Group-31 batteries, charger, and solar panel come in about equal to my former diesel. I got rid of more than the engine. Fuel, tank, filters, hoses, muffler, oil, coolant all are gone too.

Price. Sure you can pay a lot if you wish, but mine was under $7,000 for everything.

Complexity. I have no clue what this means. It's simple DC wiring and if the motor has a problem..... well, I have a spare motor in a locker that can be installed in 15 minutes with a couple wrenches.

Reliability. We throw the switch and go. In the past year I greased the thrust bearing once. That was my total maintenance. Several cruisers we have met this year have had diesel problems. We have had none.
__________________
Merrick
Diesel Free since '07
Rising Star is offline   Reply With Quote
Old 13-07-2009, 07:00   #19
Registered User

Join Date: Feb 2008
Posts: 2,061
Quote:
Originally Posted by Rising Star View Post
Putting the word electric anywhere near the word propulsion seems to cause blood pressure increases. Since I actually have an electric system in operation perhaps I can address some issues from the the real world. Because I don't know what system Peter will use I will use my own as a basis for rebuttal.






Simple answer:
  1. weight (we could stop here)
  2. price
  3. complexity
  4. with more complexity comes less reliability
Weight - My system of motor, 8 AGM Group-31 batteries, charger, and solar panel come in about equal to my former diesel. I got rid of more than the engine. Fuel, tank, filters, hoses, muffler, oil, coolant all are gone too.

Price. Sure you can pay a lot if you wish, but mine was under $7,000 for everything.

Complexity. I have no clue what this means. It's simple DC wiring and if the motor has a problem..... well, I have a spare motor in a locker that can be installed in 15 minutes with a couple wrenches.

Reliability. We throw the switch and go. In the past year I greased the thrust bearing once. That was my total maintenance. Several cruisers we have met this year have had diesel problems. We have had none.




No blood pressure rise here.... I would very much like to see a viable system. I'm a skeptic because when I tried to work the numbers it always came out twice the weight and cost, and half the power/range. Since you offered to get specific, please tell us more about your system:
  1. You have no generator?
  2. How do you charge? (specifics of charging systems?)
  3. What diesel engine did you replace?
  4. What electric drive motors do you use? (make/model)
  5. What is the power output of your electric drive engines?
  6. What is the weight of your electric drive engines?
  7. What size boat? (Monohull or multihull?)
  8. How fast do you motor in still air/water?
  9. What is your estimated range under electric power, in still air/water?
A Group 31 battery weighs about 72 pounds. So you have 550-600 in batteries for propulsion. That's slightly more than most diesel engines for a sailboat. Add the drive motor. Can you motor more than 40 miles on 8 GRP-31s without a genset? Add a genset and you can't do away with the diesel tank. How much does a genset weigh that's capable of sustaining the engines continuously? Where's your final cost?
__________________
SailFastTri is offline   Reply With Quote
Old 13-07-2009, 13:29   #20
Registered User
 
Rising Star's Avatar

Join Date: Jun 2009
Location: aboard
Boat: Freedom 32
Posts: 65
SailFastTri,
A very good set of questions! You have obviously done some research.

1) I do have a generator. A Honda 2000i that I would have taken cruising anyway. It seems to be the choice of many cruisers for those distant anchorages. I also confess to using it for those no-wind times to power my battery charger. I once ran it 17 hours straight, not my proudest moment; however, there was not a breath of wind during those 17 hours.

2) My perferred method of charging is a 48v 200 watt solar panel. A distant second is the Honda powering a Zivan 18A charger. The solar panel will recharge one bank of batteries during 2 sunny (or mostly) days. I have 2 separate battery banks of 4 AGM's each - 48v/100A each bank. I like redunancy where possible.

3) I got rid of my yanmar 3GMD, transmission, and a host of hoses, 30 gallon alum fuel tank, motor mounts, raw water filter, alternator, spare alternator, fuel filters, and a few gallons of oil and coolant. Stuff you don't even think about very often is suddenly another 5 or 10 pounds headed for the dumpster. As an added bonus I removed the raw water intake and exhaust and epoxyed them shut forever.

4,5,6) My 80 lbs system is from Electric Yachts. Specs are on their web site: Electric Yacht - Electric Yachts Mission NOTE: disclaimer - I was very happy with their system, service and price and sent in a glowing report which is on their site as a customer testimonal.

7) I have a Freedom 32 (9K disp) that I admit is a design well-suited for electric.

8,9) It is a geometric curve. I like to putter along at 3.5 - 3.8 knots and that uses 18A per hour. Hull speed would use 60A. Notice that 18A is the replacement value for my charger.

To answer the question you were too polite to ask: cost breakdown:
$3,000 for Electric Yacht system and cables (winter special price)
$1,100 for solar panel
$145 for solar controller
$1,675 for batteries ( a great sale)
$545 for Zivan charger
$300 for misc elec switches and fittings

Now the bad news:
Forget re-gen if you can't sail at hull speed. It looks good on paper, but not so good in real life.
If you are in a hurry or don't like to raise the sails at every opportunity, or want to motor if the wind is ahead of the beam - then this is not the right setup for you. But if the term "auxiliary" has real meaning to you this method might work.
__________________
Merrick
Diesel Free since '07
Rising Star is offline   Reply With Quote
Old 13-07-2009, 15:14   #21
Registered User

Join Date: Feb 2008
Posts: 2,061
Quote:
Originally Posted by Rising Star View Post
SailFastTri,
A very good set of questions! You have obviously done some research.

1) I do have a generator. A Honda 2000i that I would have taken cruising anyway. It seems to be the choice of many cruisers for those distant anchorages. I also confess to using it for those no-wind times to power my battery charger. I once ran it 17 hours straight, not my proudest moment; however, there was not a breath of wind during those 17 hours.

2) My perferred method of charging is a 48v 200 watt solar panel. A distant second is the Honda powering a Zivan 18A charger. The solar panel will recharge one bank of batteries during 2 sunny (or mostly) days. I have 2 separate battery banks of 4 AGM's each - 48v/100A each bank. I like redunancy where possible.

3) I got rid of my yanmar 3GMD, transmission, and a host of hoses, 30 gallon alum fuel tank, motor mounts, raw water filter, alternator, spare alternator, fuel filters, and a few gallons of oil and coolant. Stuff you don't even think about very often is suddenly another 5 or 10 pounds headed for the dumpster. As an added bonus I removed the raw water intake and exhaust and epoxyed them shut forever.

4,5,6) My 80 lbs system is from Electric Yachts. Specs are on their web site: Electric Yacht - Electric Yachts Mission NOTE: disclaimer - I was very happy with their system, service and price and sent in a glowing report which is on their site as a customer testimonal.

7) I have a Freedom 32 (9K disp) that I admit is a design well-suited for electric.

8,9) It is a geometric curve. I like to putter along at 3.5 - 3.8 knots and that uses 18A per hour. Hull speed would use 60A. Notice that 18A is the replacement value for my charger.

To answer the question you were too polite to ask: cost breakdown:
$3,000 for Electric Yacht system and cables (winter special price)
$1,100 for solar panel
$145 for solar controller
$1,675 for batteries ( a great sale)
$545 for Zivan charger
$300 for misc elec switches and fittings

Now the bad news:
Forget re-gen if you can't sail at hull speed. It looks good on paper, but not so good in real life.
If you are in a hurry or don't like to raise the sails at every opportunity, or want to motor if the wind is ahead of the beam - then this is not the right setup for you. But if the term "auxiliary" has real meaning to you this method might work.
The original question on this thread was about "motoring time" for an ocean crossing, so I apologize for taking this in another direction. Quite frankly I don't see how that question can be answered, as it always depends on many things.

But Rising Star -- you asked why I haven't pulled the trigger on electric drive, and it's because the numbers still don't work out... I think if you go that route with the present technology it's because you want to, not because it makes sense (like buying a boat in the first place )

You traded out a 20 hp 350 lb. engine plus 30 gallon diesel fuel tank (7.3 lb/gallon or 250lb full) that could motor your boat at hull speed for about 50-60 hours, with a total engine/fuel weight of about 600 pounds. In exchange you got a ~850+ pound system that can motor at 2.5 to 3.5 knots (only if there is no strong headwind or big seas) that puts out half the power of the diesel engine at top current utilization and can't be sustained at that high level with the little Honda genset, which also requires you to carry a more volatile fuel in containers and would be difficult to refuel in a seaway without spilling. Many people would have a problem finding space to mount 200-watts of solar panels on a 32-foot monohull. (How much does the arch/mounts weigh with those panels? My 850lb number includes ~100 lbs.)

I don't see the advantage. If you're only going to use it as an auxiliary in no-wind you could save a LOT of weight and money by using an outboard gas engine.

Even the silence you gain using electric only as a true auxiliary doesn't compensate for what you give up. If you do any sustained motoring you still need to listen to (and smell) the gas genset to recharge or motor on a no-wind day, and it will be ineffective in sustained motoring against a strong headwind.

If you added a diesel genset to provide enough electric power and motor strong enough to be a direct replacement for the diesel engine you removed, you would be back to twice the weight and twice the cost, but then you'd have quieter generation and the ability to sustain motoring into a strong headwind.
__________________
SailFastTri is offline   Reply With Quote
Old 13-07-2009, 16:21   #22
Registered User
 
Rising Star's Avatar

Join Date: Jun 2009
Location: aboard
Boat: Freedom 32
Posts: 65
SailFastTri,
You are correct if you assume I tossed out a working diesel. I fixed and repaired that $#@&* diesel for 3 years. I had a friend with 30 years of Navy diesel experience help me repeatedly. I had the pros at the marina look at it and "fix" several things. I admit to developing an intense dislike of diesel and an equally intense dislike of spending my boating time prone on the sole getting greasy and dirty without any improvement - while watching the dollars roll down the drain.

Going electric changed that. I am a sailor again.

I won't dispute your facts, we could discuss all day what the weight of various items are and if they fit into the electric side or boating side. It is just my opinion that I would have a Honda 2000i and a 5 gal. can of gas regardless of propulsion method.

I am very luckly to have a wife that enjoys taking the helm and beating into the wind. Not my favorite point of sail, but it is a sailboat.

As I pointed out in my last paragraph how you view sailing vs. motoring is critical to acceptance or disapproval of electric powered boats. It has reached my acceptance level. Maybe in a few years technology will help it reach your acceptance level.
__________________
Merrick
Diesel Free since '07
Rising Star is offline   Reply With Quote
Old 13-07-2009, 18:41   #23
Registered User

Join Date: Nov 2008
Posts: 81
Hmm guys since I did ask the original question and since I have a personal desire to go down the electric route, am REALLY glad to see a conversatrion of smart guys who know there stuff and are into the facts not the religious arguments

I am seeing some great arguments for at this time not switching over, but I think the availability of deep cycle Li_Ion batteries and the next generation solar cells may be the missing aspects to making this the norm in cruising! I will be cruising 80% of the time +/- 30degrees from the equator I figure a large solar rig will do wonders for me but only in 5-8 years I suspect (based on good research and agreeing the technology is not really ready for prime time yet)
__________________
peter.bomberg is offline   Reply With Quote
Old 14-07-2009, 06:00   #24
Registered User

Join Date: Feb 2008
Posts: 2,061
Sailing vs. Motoring

Quote:
Originally Posted by Rising Star View Post
SailFastTri,
You are correct if you assume I tossed out a working diesel. I fixed and repaired that $#@&* diesel for 3 years. I had a friend with 30 years of Navy diesel experience help me repeatedly. I had the pros at the marina look at it and "fix" several things. I admit to developing an intense dislike of diesel and an equally intense dislike of spending my boating time prone on the sole getting greasy and dirty without any improvement - while watching the dollars roll down the drain.

Going electric changed that. I am a sailor again.

I won't dispute your facts, we could discuss all day what the weight of various items are and if they fit into the electric side or boating side. It is just my opinion that I would have a Honda 2000i and a 5 gal. can of gas regardless of propulsion method.

I am very luckly to have a wife that enjoys taking the helm and beating into the wind. Not my favorite point of sail, but it is a sailboat.

As I pointed out in my last paragraph how you view sailing vs. motoring is critical to acceptance or disapproval of electric powered boats. It has reached my acceptance level. Maybe in a few years technology will help it reach your acceptance level.
Sailing vs. Motoring
I sail a 12-meter cruising trimaran, so you can assume (correctly) that I love to sail and can make good progress sailing in light air when many lower-performance boats will motor. The less motoring we have to do the better. I don't want to weigh the boat down with unnecessary performance-killing loads.

I dislike extended motoring but (like many others who need to earn a living) my time for cruising is limited and we occasionally find ourselves in "scheduled delivery mode" particularly at the end of a vacation cruise when we need to get the boat to home port -- often either to-windward or when lacking wind. For that reason I want a motor that can move the boat at "hull speed" (cruising speed under power is 8 knots for us) and must be able to motor for extended times between stops for refuel (or in your case, recharge). A diesel-electric hybrid must be able to sustain extended motoring by refueling, or it will not meet the needs of "delivery mode", and motoring at 3-4 knots is not acceptable when one needs to move the boat 100+ miles and "you'd rather be sailing" .

Here's a recent photo of our wake while sailing at 13-14 knots in flat water.


Bottom-line is every design decision involves trade-offs and compromises: I wouldn't want to kill sailing performance by excessive weight of a propulsion system, and if you're going to sacrifice some degree of sailing performance for mechanical propulsion the weight impact should be minimal and the balanced goal should be that it will able to motor at an acceptable speed into a moderate headwind, and have a decent range without excessive time between refuel (or recharge).

One more consideration is that where we sail the typical tidal currents are 1-2 knots, and in certain areas the currents can exceed 5 knots. Being able to motor against a current is a safety advantage.
__________________
SailFastTri is offline   Reply With Quote
Old 14-07-2009, 07:59   #25
Vendor
 
witzgall's Avatar

Join Date: Oct 2006
Location: Eastern Shore, MD
Boat: Camper Nicholson 44 Ketch
Posts: 1,775
The battery world is slowly being turned around by the introduction of LIFEPO4, or Lithium Phosphate batteries. They currently cost about $1.20 per AH @3.6-3.8v, + Management and charging system. They last 2-3k cycles, so the cost benefit is there.

My knowledge of these batteries is not practical. I have the parts coming to build a 24v 40ah battery for our Torqueedo. Once I have that up and running for awhile, I will have some first hand knowledge.

Chris


Quote:
Originally Posted by SailFastTri View Post
Just to carry this a bit further, let's assume you want a genset that will sustain propulsion, and electric motors that are less than half the power of the MD-22p I mentioned. Assume you don't expect the batteries to sustain electric power beyond a few miles, so you use the smallest GRP-24 batteries (about 60 lb. each). If you need at least 60 volts you need a minimum of 300 lbs of extra batteries, plus your house bank, genset start battery, genset and drive motors.

Adding all that extra weight on a multihull is like giving sugar to a diabetic.

And what do you accomplish?
__________________
witzgall is offline   Reply With Quote
Old 14-07-2009, 18:37   #26
Registered User

Join Date: Feb 2008
Posts: 2,061
Quote:
Originally Posted by witzgall View Post
The battery world is slowly being turned around by the introduction of LIFEPO4, or Lithium Phosphate batteries. They currently cost about $1.20 per AH @3.6-3.8v, + Management and charging system. They last 2-3k cycles, so the cost benefit is there.

My knowledge of these batteries is not practical. I have the parts coming to build a 24v 40ah battery for our Torqueedo. Once I have that up and running for awhile, I will have some first hand knowledge.

Chris
Check out the "Advantages and disadvantages" section of Lithium iron phosphate battery - Wikipedia, the free encyclopedia

It appears those batteries are not the solution either. Poor deep-cycle and rapid recharge tolerance? Low energy density?

Not ready.
__________________
SailFastTri is offline   Reply With Quote
Old 14-07-2009, 18:50   #27
Registered User

Join Date: Nov 2008
Posts: 81
SailFastTri, I agree not ready yet but the energy density is still very good compared to lead (almost double) so for the same AH you are looking at a 50% weight reduction, also deep cycle tolerant after a burn in and so we can only trickle charge (that is the plan with solar anyways).

I would say 3-5 years out but a promising development.
__________________
peter.bomberg is offline   Reply With Quote
Old 14-07-2009, 19:37   #28
Vendor
 
witzgall's Avatar

Join Date: Oct 2006
Location: Eastern Shore, MD
Boat: Camper Nicholson 44 Ketch
Posts: 1,775
Sailfast;

I would suggest that you expand your sources of information to give you a more complete picture of this technology. Most LIFEPO4 cells of the size and type that would be used on a boat have 2-3k cycles to 70-80% of discharge. They can handle a minimum of 1c ( one times the AH rating of the individual cells) charging, most likely more. The energy density is lower than the Li-on pack in your laptop, but WAY more dense than any AGM, gel or Wet celled battery.

There are different designs for wet cells, for different goals. Compare a starting battery from your auto parts store with a Rolls Surrette 8D, as an example.

Here is the site of the seller I am buying the cells from. There are some spec sheets you can view: http://www.evcomponents.com

Look there and elsewhere on the web for info on cells from 40-800ah, these are the size cells that will make their way onto boats, and are already being used by the EV auto converters.

Chris


Quote:
Originally Posted by SailFastTri View Post
Check out the "Advantages and disadvantages" section of Lithium iron phosphate battery - Wikipedia, the free encyclopedia

It appears those batteries are not the solution either. Poor deep-cycle and rapid recharge tolerance? Low energy density?

Not ready.
__________________
witzgall is offline   Reply With Quote
Old 14-07-2009, 22:56   #29
Registered User
 
roger.waite's Avatar

Join Date: Jul 2008
Location: Plimmerton, New Zealand
Boat: Samsara, a Ross 930
Posts: 380
Interesting thread. On both sides of the discussion ...

I wonder whether any battery technology under development will resolve problems raised by those thinking "must go fast for long periods to get back to work / through the tidal gate / out of harms way". The problem they perceive is primarily sustained power generation (e.g. 50-100A), rather than storage?

Rising Star's main power source is the right one to emphasise (continuous generation). Bigger generators exist. Electric propulsion works and, as Rising Star points out, it can be simpler to repair. But for now, what I have works pretty darned well, so I can let someone else shake the bugs out ...

Liked Mark's comments on simplicity.
__________________
roger.waite is offline   Reply With Quote
Old 18-08-2009, 22:45   #30
Senior Cruiser
 
FSMike's Avatar

Cruisers Forum Supporter

Join Date: Aug 2009
Location: Bahamas/Florida
Boat: Solaris Sunstar 36' catamaran
Posts: 2,654
Images: 5
Peter -
If you plan on long distance cruising I would reconsider not having a wind generator.
Solar doesn't work real well at night or during cloudy days for that matter, but that's often when the wind is up.
__________________

__________________
FSMike is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
When It Isn't Your Time To Go . . . TaoJones Health, Safety & Related Gear 9 20-01-2009 18:48
Motoring South From Atlantic City NJ - Miami Florida In September Barbie Atlantic & the Caribbean 0 07-09-2008 12:19
First time poster, long time sailer. Richkd Meets & Greets 16 31-08-2008 07:18



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 18:36.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.