Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 02-05-2015, 05:30   #46
Registered User

Join Date: Apr 2013
Posts: 4,877
Re: Elon Musk's New System -- Good for Boats? Long number filled question

Quote:
Originally Posted by TacomaSailor View Post
Please help me understand what I seem to mis-understand.

Ive been thinking about my sailboat cruising time and the possibility of using an electric motor for propulsion. Here is the data I am using to make comments and observations about electric propulsion.

- Four trips from Seattle to San Diego (6,000 NM)
- Two trips from San Diego to Puerto Vallarta and back ( 2,000 NM)
- Three years cruising in the Sea of Cortex and Western Mexico (4,500 NM)
- One trip from Annapolis to BVI (1,500 NM)
- Many overnight and multiple day trips from San Diego to Catalina, Ventura, Santa Barbara, Newport, Oceanside (~1,000 NM)

Assuming an average speed of 5 knots (lots of slow sailing) that is about 3,000 HOURs underway.

My Caliber 40 cutter needs about 8 Horsepower at the prop to motor at 5.5 knots in flat, calm water. That is about 6 Kilowatts of power at 100% efficiency. I know my 18 x 15 Maxprop is not 100% efficient but Ill assume the max possible efficiency in order to minimize electrical energy demand. I will also ignore the need for more power needed to motor into currents, swells, and waves.

I keep very detailed records about wind, waves, motoring, and sailing. I sail almost any time I can keep the boat moving at 3.5 knots or greater. I have a big Code 0 and an even bigger lightweight spinnaker I love to fly. My records show that I sail about 53% of the time. But, what is more interesting is that my records show many, many, YES MANY, intervals where we motor for more than 12-hours at a time due to there being no wind at all NONE!

For example the last two days before arriving in the BVI we had not a single breath of wind while motoring at 7 knots (~330 NM). This was in a very high tech lightweight 53 sloop with a huge array of light air sails.

The problem AT SEA with calm winds is the constant swell rolling by. In my experience, it is not possible to comfortably just sit in that swell with no way on to keep the boat aligned to the swell. Therefore, the boat must be kept moving. My boat needs about 3.5 HP ( ~2.6 Kw) to move at 3.4 knots in calm seas and wind.

The data above shows that I need sufficient battery power to produce about 3 Kw of propulsion energy for up to 24-hours. That means I need to store 72 KwH of energy and, to keep from drawing batteries below 50%, I need about 144 KwH of energy.

Additionally, I need sufficient battery capacity to pull up to 6 Kw (5.5 knots) of power for many hours without damaging the battery. If I want to use a 20-hour withdrawal rate I therefore need about 120 KwH of energy storage.

The batteries being discussed here are $3,500 for 10KwH so I would need 12 10KwH batteries at a cost of $42,000. Assume they weigh 310 pounds each that is 3,700 pounds of batteries. ( A 300 amp hour 8-D LeFePO4 weighs 93 pounds and can deliver 3 KwH when discharged 80% so 10KwH would weigh about 310 pounds)

Now, how do you recharge that big battery bank?

Assuming you can put power back into the batteries at the same rate you withdraw it you will need a 3.5 Kw generator to recharge the batteries. The lightest I can find is a NextGen 3.5 which weighs 160 pounds and burns 0.2 GPH. If I need 20-days recharging then I would need 96 gallons of diesel (0.2*24*20) or 672 pounds.

My generator, diesel fuel, batteries, and 48V traction motor (40 pounds) would weigh a total of 4,572 pounds (3700+160+672+40). All that equipment would cost about $50,000.

My Yanmar 4JH2E weighs about 500 pounds with its transmission and fluids. One Hundred gallons of diesel ( 750 miles ) weighs 700 pounds.

So just the batteries needed for electrical propulsion weigh more than three as much as my current diesel and fuel. Even if I add in the 500 pounds my two 8-Ds weigh the electric power system weighs twice what my diesel and big house battery bank weighs.

The bottom line is that it takes about 1.5 KwH to move my boat one nautical mile at a normal cruising speed. The Yanmar burns (measured over thousand of hours) 2 ounces of diesel to accomplish that. The NextGen burn 1.4 ounces of diesel to put 1.5 KwH back into the battery at 100% efficiency or 1.6 ounces at 90% efficient conversion of diesel energy to torque at the prop .

I can put in a new Yanmar, propshaft, and Maxprop for less than 1/4 the price of the electrical system.

What then is the advantage of diesel electric power?

I have 500 watts of solar panels and in Mexico in the bright summer sunshine I can put about 225 amp hours back into the batteries at 14 volts. That means I am recharging at about 20% of the rate I am using power OR for each hour I use the electric propulsion motor (2.6 Kw) I need 5-hours of maximum solar power to replace the energy.

I also have a Ferris towed generator, which produces 7 amps at 5.5 knots sailing and 12-amps at 7 knots sailing. That means I need about 20 hours of sailing and towing the generator to replace ONE hour of motoring. And, the generator slows the boat by 0.3 knots when sailing at 7-knots.

Tell me how electrical propulsion makes sense for a cruising sailboat.

What is wrong with my analysis based on 13,000 NM of cruising and 15-years of living with only solar power on the boat?
It builds your eco-street cred

After that, it's pretty silly. If you accept the limitations of battery/electric system, you are probably using less than 10gal of diesel per year to begin with.

You beat me to posting basically the same description of capability. The basic pack will put out 10hp for less than an hour. A 1kw solar array will take multiple days to refill that battery pack. To get any reasonable range and the numbers get crazy very quickly.
__________________

__________________
valhalla360 is offline   Reply With Quote
Old 02-05-2015, 05:41   #47
One of Those
 
Canibul's Avatar

Cruisers Forum Supporter

Join Date: Sep 2006
Location: Turks and Caicos Islands
Boat: Catalac 12M
Posts: 3,209
Re: Elon Musk's New System -- Good for Boats?

so....if I just use my solar and wind thru my MPPTs to charge this battery to power a small electric motor to wind up a big rubber band....which I can use to power a dc generator which I can run through an inverter to get ac, which I can then immediately convert back to dc , to charge my laptop battery so I can write these posts....

Yeah, that's worth $3500...
__________________

__________________
Expat life in the Devil's Triangle:
http://2gringos.blogspot.com/
Canibul is offline   Reply With Quote
Old 02-05-2015, 08:23   #48
Marine Service Provider

Join Date: May 2013
Location: East Africa
Boat: catalac 10m
Posts: 351
Elon Musk's New System -- Good for Boats?

Constructive criticism please. Innovation has to be applauded, giving expectations for electric auxiliarys with 18 to 30 hp, prefered output fir our sail boats, is dreaming. Hey isnt most innovation tantamount to realizing dreams. Tesla's efforts to focus on storing energy rather than on the energy producing part of alternative energy set up has to be applauded. I get very irrirated with so-called aid agencies claiming to solve energy problem in the third world with solar panels forgetting to mention the cost of the energy storage, how on earth can the owner of a stick and mud hut in central Africa afford any battery, even giving him a solar panel wont help him, it will become a table top or cover for his chicken run. Lets salute Tesla for their courage and drive for innovation, may this initiative lead to great yacht energy storage.


Sent from my iPad using Cruisers Sailing Forum
__________________
Goosebumps is offline   Reply With Quote
Old 02-05-2015, 08:37   #49
Registered User

Join Date: Apr 2013
Posts: 4,877
Re: Elon Musk's New System -- Good for Boats?

Quote:
Originally Posted by Goosebumps View Post
Constructive criticism please. Innovation has to be applauded, giving expectations for electric auxiliarys with 18 to 30 hp, prefered output fir our sail boats, is dreaming. Hey isnt most innovation tantamount to realizing dreams. Tesla's efforts to focus on storing energy rather than on the energy producing part of alternative energy set up has to be applauded. I get very irrirated with so-called aid agencies claiming to solve energy problem in the third world with solar panels forgetting to mention the cost of the energy storage, how on earth can the owner of a stick and mud hut in central Africa afford any battery, even giving him a solar panel wont help him, it will become a table top or cover for his chicken run. Lets salute Tesla for their courage and drive for innovation, may this initiative lead to great yacht energy storage.


Sent from my iPad using Cruisers Sailing Forum
For a guy living in a mud hut, they are probably charging a cell phone and watching TV for a couple hours a day. A single deep cycle battery is likely plenty for their needs with a solar panel.

As many of these threads discuss, if you are willing to live with negligible energy consumption, lots of things are viable but your average 1st world cruiser expects a higher standard of living. I'll leave it up to others to decide if that is right or wrong.

Of course, I haven't seen much innovation from tesla. Lots of hype using old technology but not much in the way of innovation.
__________________
valhalla360 is offline   Reply With Quote
Old 02-05-2015, 09:53   #50
Registered User
 
transmitterdan's Avatar

Join Date: Oct 2011
Boat: Valiant 42
Posts: 4,023
Re: Elon Musk's New System -- Good for Boats?

Tesla do not have some new magical battery chemistry. They use modern manufacturing techniques (and lots of local government assistance $) to mass produce battery systems that utilized fairly ancient technology by battery calendars. Also, they are not much focused on making a profit, at least right now. This is a business play not a technology play. Time will tell if the bean counters and six sigma black belts can put this technology on par with fossil fuel economically. A lot of people think the business plan is good because Tesla stock is high. A lot of other people think the business plan is foolish. Time will sort it out. But don't think that Tesla have some secret battery the rest of the world doesn't have because that is not the case.
__________________
transmitterdan is offline   Reply With Quote
Old 02-05-2015, 16:20   #51
Marine Service Provider

Join Date: May 2012
Location: New Orleans
Boat: We have a problem... A serious addiction issue.
Posts: 3,940
Re: Elon Musk's New System -- Good for Boats?

One of the things that is missing in this discussion is exactly how massive the new Tesla factory really is. The most recent numbers I have is that in 2013 there was a worldwide combined production of 23Gwh of advanced battery production WORLDWIDE. To give an idea of scale, the new plant is expected to produce 50Gwh of batteries when fully operational, and 30Gwh in 2017. At one fell swoop then Tesla becomes the biggest advanced battery producer in the world, contributing more than 50% of worldwide production capability in one plant.

This isn't just a 'oh look cool new wall hanging' issue, Musk is intentionally disrupting world supply chains, and is almost singlehandedly going to make every other battery fabricator overpriced.

The entire reason for this initially was that Tesla couldn't source enough batteries for their expected demand. If Tesla comes anywhere close to its target of 500k electric cars a year by 2020 they would have needed 90% of world wide battery production. The disparity between what Tesla wanted to buy and what was produced worldwide was just too high.

This wall hanging battery is just a spin off of the fundamental production plant. Once you can produce batteries cheap enough and in sufficient quantity then things like this become simply a fabrication issue instead of a resource concern.

And keep in mind, Musk has already hinted at plans to build a second factory this size.
__________________
Greg

- If animals weren't meant to be eaten then they wouldn't be made of food.
Stumble is offline   Reply With Quote
Old 02-05-2015, 16:26   #52
Registered User
 
transmitterdan's Avatar

Join Date: Oct 2011
Boat: Valiant 42
Posts: 4,023
Re: Elon Musk's New System -- Good for Boats?

Tesla can't move enough cars to justify the big plant thus they need more demand for batteries. That's what this press release is really about.
__________________
transmitterdan is offline   Reply With Quote
Old 02-05-2015, 16:54   #53
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,042
Re: Elon Musk's New System -- Good for Boats?

Capn Bill-
" They have lost a couple of their cars to battery fires. The cars do not use LiFePo4 battery " Bear in mind those fires were from incidents like stuffing a large piece of road debris THROUGH an armor shield and into the battery pack. No battery likes that, and they've responded by installing even heavier armor as a free retrofit. And while the cars were lost, the occupants were able to simply pull over and walk out.
Compared to the number of gasoline cars that combusted last year, I think Tesla still comes out way ahead. Ford's ignition switch fires, a batch of monoxide deaths, carburetor and other fuel leaks, and let's not forget, two cars are set on fire in US gas stations where people just HAD to light up a cigarette at the pumps every year...Tesla comes out smelling like a rose farm on that score. They also had chosen 18650 battery cells (like fat AA cells) so that any one failure and resulting fire from manufacturing issues would be a small event.
As for not using LiPo chemistry, no that will never happen. No one can afford to throw away 10% of the car's range and power, and that's what LiPo does.


By the way, if you have a car fire on the road and call 911, as I recently did these days? They make Real Damned Sure to ask you what kind of fuel the car uses, whether it has any battery or EV, so they can brief the responders on how to not get electrocuted while responding. That's a more serious issue with electric cars, the responders won't go near them unless there's a Big Red Switch they can pull.


Stumble-
What people seem to forget is that at $70,000+ per vehicle, with perhaps $30,000 tied up in the battery Tesla is eventually going to fail (it has nearly gone bankrupt before) unless Musk can radically reduce battery costs. He has said openly that can only happen by ramping up production to a much larger scale, and especially with their sales in China falling flat, his sales projections have had no correlation to reality. So in his logic--according to his own speeches--he's got to scale up battery production (which Panasonic withdrew from, thinking it was not going to be possible to make a profit) to an incredible point. And having committed to that, and basing his Tesla business on that, now he's had to figure out a way to sell huge quantities of batteries when there's no market for them.
So like Gilette (give away the razors, create a market for blades) he's trying to pull battery-hungry rabbits out of his hat, going for a Hail Mary pass that if he creates a demand for batteries, the whole series of gambles can work.


Hey, I wish him good luck. If he can cut Tesla prices in half and assure me of five-minute fuel stops anywhere, anytime, all over the US? I'd be thrilled to drive one too. Meanwhile...I've done trips with 4-6 fuel stops on the interstate, and there's no way in hell I'd want to spend an hour at each stop. Assuming there were no other users lined up ahead of me.


Maybe if he offered free "whole body massage with benefits" and catering, the stops wouldn't seem so long?(G)
__________________
hellosailor is offline   Reply With Quote
Old 02-05-2015, 18:35   #54
Marine Service Provider

Join Date: May 2012
Location: New Orleans
Boat: We have a problem... A serious addiction issue.
Posts: 3,940
Re: Elon Musk's New System -- Good for Boats?

Unless Panasonic has pulled out since February so far as I know they and Tesla are still partners in the gigafactory.

As I see it Tesla right now has two issues.

First is that their cars are too expensive for the average person. I see this as a function of three issues: a) because their cars are designed for the luxury market b) the cost of the batterie packs is too high, c) because they aren't building enough vehicles to drive down marginal costs per car.

Second is that Tesla can't source the number of batteries they would need to build many more cars. If they tried the auction of battery production worldwide would just drive up the price of their cars.

If you treat each of these as discrete issues they all seem solvable. With a huge chunk of the problem going away as soon as the new factory comes on line. They also need to design a less expensive (ie economy) car targeted at Honda, instead of the luxury cars they are currently building.

Assuming they can get the price down, sales go up, and marginal costs come down. As soon as there is a reasonable vehicle density on the road I would imagine gas stations will add high speed charging stations. From a technical standpoint adding a charger is a pretty simple and cheap proposition. There just has to be demand to support it.


I should note that while I am a big fan of Tesla, I have chosen not to own any stock. For now the share price I think is unreasonably high compared to earnings. So I am not blinded by what they are doing, just very curious.
__________________
Greg

- If animals weren't meant to be eaten then they wouldn't be made of food.
Stumble is offline   Reply With Quote
Old 02-05-2015, 18:40   #55
Registered User

Join Date: Jan 2014
Location: Deerfield Beach, FL
Boat: Islander MII 32
Posts: 45
Re: Elon Musk's New System -- Good for Boats?

It can only be good!
That's the breakthrough we have all been waiting for. wanting a renewable energy bank that sits under your feet!
The next step is using the keel lead as a battery. Who wants to pitch ideas?
__________________
michaeltayar is offline   Reply With Quote
Old 02-05-2015, 19:36   #56
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,042
Re: Elon Musk's New System -- Good for Boats?

Greg-
"Unless Panasonic has pulled out since February"
I'd read they were o-u-t out. But it wouldn't be the first time a company reversed their intentions.


"First is that their cars are too expensive for the average person." You think, a $20,000+ battery pack might affect that? Or the need to have a private home, which is for most people the only way to install a home charger? And, that little leash caused by not being able to go away for the weekend if you dream or need to drive 200+ miles and find a charger at the other end yet?


" Tesla can't source the number of batteries they would need to build many more cars." Nah. With the way the Chinese market tanked, they've already got access to more batteries than they can shake a stick at. They can't figure out how to sell what's already in inventory, let alone coming off the line.


"With a huge chunk of the problem going away as soon as the new factory comes on line." Quite the opposite! Even with the most optimistic projected sales, based on what they HAVE been able to sell not what Elon would like to sell, if that factory starts up they are going to have the world's first 20-hour work week and still be stacking the batteries up to the ceiling. His projections just haven't matched actual sales, and show no ability to reconcile the two.


" They also need to design a less expensive (ie economy) car targeted at Honda, instead of the luxury cars they are currently building. "
Well, yeah, there is it again. You can't compete with a $20,000 car when you've got a $20,000++ battery pack, a smaller support structure, and no way for the average driver. Who parks on the street or in a lot with no ability to recharge there, and no time to queue up for hours at one local charging post then come back to move the car. I buy the Honda, I stop for five minutes on the way home, I'm good for 600 miles. He'd have to send around "charging valets" to come by in the middle of the night and quietly top up the cars to make street parking and ownership feasible. Which, I suppose, I should suggest to him. They could partner with Audi (which Amazon? or DHL? in Germany is already doing, I heard) to deliver your packages to your trunk at the same time, using the car's GPS to locate where you need the delivery to actually be.


"From a technical standpoint adding a charger is a pretty simple and cheap proposition. " Not really. A gas pump has a 5-minute turnover time, unless some idiot parks at it then goes inside to find out what color Slurpee and tacos they can find. Now take a Tesla, the turnover is one? two? customers per hour instead of 12. And if someone decides to park then go grab lunch inside while it is charging...that becomes one hour per station, and it makes the charging stations--which can only accommodate Teslas, not Nissans or anything else--into a very expensive investment. No way I'd install one, and buy the real estate to have someone park at it, unless it was UNIVERSAL and took less than ten minutes per customer. Gotta make more money on the charging station than I can from selling coffee, tacos, and gas per square foot.

The stock has been really good to a lot of people, but with no business plan that shows a profit date and solid basis for expecting a profit? Does the phrase "internet bubble" seem familiar? I've just read too many numbers that say his solutions are still impressive dreams, but based on pure speculation.
__________________
hellosailor is offline   Reply With Quote
Old 02-05-2015, 20:12   #57
Registered User

Join Date: Jan 2010
Location: Port Ludlow Wa
Boat: Makela,Ingrid38,Idora
Posts: 1,973
Re: Elon Musk's New System -- Good for Boats?

More power to Elon. The Howard Hughes of our time.
__________________
IdoraKeeper is offline   Reply With Quote
Old 03-05-2015, 06:33   #58
Registered User

Join Date: Oct 2009
Location: New York City
Boat: 1991 Lagoon 55
Posts: 22
Re: Elon Musk's New System -- Good for Boats?

I'm kinda disappointed in the Marine applications of the new Tesla powerwall batteries. Apparently they have to be on a wall and can not be mounted flat - something to do with the thermal cooling unit. That doesn't sound like it's going to work on a boat.

:-(
__________________
JamesANGreen is offline   Reply With Quote
Old 03-05-2015, 06:46   #59
One of Those
 
Canibul's Avatar

Cruisers Forum Supporter

Join Date: Sep 2006
Location: Turks and Caicos Islands
Boat: Catalac 12M
Posts: 3,209
Re: Elon Musk's New System -- Good for Boats?

Quote:
Originally Posted by Goosebumps View Post
Constructive criticism please. Innovation has to be applauded,
Sent from my iPad using Cruisers Sailing Forum
Sorry, but hanging a car battery on the wall because the cars aren't selling doesn't really strike me as Nobel material. Especially when my tax dollars were grabbed to develop it all in the first place.

But then, Nobel isn't Nobel material anymore, either.
__________________
Expat life in the Devil's Triangle:
http://2gringos.blogspot.com/
Canibul is offline   Reply With Quote
Old 03-05-2015, 07:10   #60
Registered User
 
transmitterdan's Avatar

Join Date: Oct 2011
Boat: Valiant 42
Posts: 4,023
Re: Elon Musk's New System -- Good for Boats?

Quote:
Originally Posted by JamesANGreen View Post
I'm kinda disappointed in the Marine applications of the new Tesla powerwall batteries. Apparently they have to be on a wall and can not be mounted flat - something to do with the thermal cooling unit. That doesn't sound like it's going to work on a boat.



:-(

That's because it isn't really a battery. Think of it more like a smart UPS. It stores AC energy in batteries when demand is low and supplies AC power when demand is high. It levels out the peaks thus saving money. The batteries in the Tesla are liquid cooled. I don't know if they can do that for a home unit so thermal management is a problem. Heat rises so they may have heat sinks and fans that allow only one mounting orientation. If I had to guess I would guess the allowed temperature range is restricted as a way to keep costs down. Most people don't let their homes get too hot or cold.
__________________

__________________
transmitterdan 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
Exhaust System Diagram (New System) SkiprJohn Engines and Propulsion Systems 19 28-08-2014 05:23
Block system for a new dinghy davit system landonshaw Auxiliary Equipment & Dinghy 3 27-03-2011 08:32
Good Morning, Good Evening and Good Night bullitt774 Meets & Greets 10 30-08-2010 15:35
New Boats Charging System AnchorageGuy Electrical: Batteries, Generators & Solar 11 21-11-2008 22:10
Hey Cascade29. Nice article on Cascade boats in the New issue of Good Old Boat Thomas Stone Monohull Sailboats 4 25-12-2003 15:23



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 19:55.


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.