Elon Musk's New System -- Good for Boats?

[jheldatksuedu]

Originally Posted by med

A lot of fuss for something which will store the equivalent of about a gallon of petrol.

And they probably will have the ability to spontaneously cause a rather impossible to extinguish fire without an ignition source, sure sounds like what I want on my boat.... I'll stick with the 150 gallons of diesel, a couple gallons of propane, a diesel generator and wind and water generator. Just because you can store a lot of energy (actually not really a lot, compared to fossil fuels) isn't going to make solar panels any better. You still would need to cover every inch of the boat with solar panels. I'm all for eliminating fossil fuel burning but it has to be practical and safe. I'll reduce my fossil fuel use by having a sailboat, a rowing dinghy and using a bike. But I will have a foldup motorcycle on board. I have riden a bike 1500miles but for a distance over 40 miles I definitely prefer a small motorcycle, even if it does use gas. I sure would like to find a small diesel, I have thoughts about a conversion of a weedwacker using a much smaller piston and cylinder, electronic injection (it's tough to control a drop or so of injected fuel) and a high pressure fuel tank. Any ideas are welcome.

[nimblemotors]

There have been 'breakthrough' battery announcements all the time for the last 20 years. Almost none of them pan out. This one isn't a technology/capacity breakthough, but a price breakthrough.

Now you don't need to buy a crashed telsa model S to get a 85kwh battery for $25,000, which can do today, but you will be able to buy the battery directly.

10kwh for $3,500 is a good price. I'd expect it to go even lower.

It is a big deal for my Indy One electric kit car, which because of its efficiency, can get 100 mile range with just a 10kwh pack.
So with a 10kwh pack at home charged via solar during the day, and a 10kwh pack in the Indy One to drive to work, all driving completely solar energy.

[trifan]

http://www.amazon.com/Watseka-Cargo-...N%3DB00J2WY53U

Electric bike, $599, up to 14 mph & averages 16-18 mile range, easy shift 6 speed Shimano gear set, 250-Watt brushless motor with a 36V 9Ah removable AGM battery pack for long lasting battery life.

I have seen foldable versions of electric bikes that would stow on a boat.

[Captain Bill]

I didn't see any statement on what chemistry this thing is using. They have lost a couple of their cars to battery fires. The cars do not use LiFePo4 battery chemistry which is the safest lithium battery technology, if not the highest capacity. If it's some other chemistry, I wonder if you'll be able to get home owners insurance for a reasonable price if you install the thing.

[hellosailor]

Article in the WSJ about Musk's new battery plans this week. Apparently the smallest "home" unit will be size size of a "small" refrigerator and priced at $24,000, fwiw.


I don't know if "small" means dorm size or kitchen size, they didn't say. And don't know if that includes a charging unit and thermal management system, like his cars use, which could also bulk up the size and create issues with heating and cooling vents. They're "coolant" controlled in the cars.


But if $24,000 on a boat battery makes you happy, by all means.


There's also reasoned speculation that his real purpose of selling "home" systems is to find an outlet for the batteries. Tesla sales have been underperforming, and the factory will at this rate be producing way more capacity than Tesla needs, so if they can't find a way to dispose of perhaps 50% of all production, literally dispose of it, the whole venture falls apart.


$24,000, fire sale prices. Hmmm...Of course, federal subsidies (& Cali) might cut 40% off that, but I think they expire in 2016?

[denverd0n]

Originally Posted by barnakiel

Just imagine where this battery puts all our posts in "electric motors NOT viable in a sailing boat".

Doesn't put them anywhere. I don't think anyone has ever said that electric motors will NEVER be viable in sailing boats. Just that right now the economics don't support it.

They still don't. This announcement doesn't change that. Given time, this may lead to a day when the economics DO support electric motors in sailing boats. I hope so. I really do. But I'm not going to hold my breath, regardless of what some press announcement might say.

[jheldatksuedu]

Originally Posted by trifan

Amazon.com : Watseka XP Cargo-Electric Bicycle-26"-6 speed-Adult/Young Adult-Black : Sports & Outdoors

Electric bike, $599, up to 14 mph & averages 16-18 mile range, easy shift 6 speed Shimano gear set, 250-Watt brushless motor with a 36V 9Ah removable AGM battery pack for long lasting battery life.

I have seen foldable versions of electric bikes that would stow on a boat.

Weedwacker powered bike, 250 mpg, range infinite with stops at gas station every 100 miles, top speed 28 mph, I rode one form Kansas to Florida a couple years ago for $22 gas, see the trip report on my website
Bike Kansas to Florida
only problem, it wears out the rear tire, I am trying to figure out a new drive mechanism but feel it must allow bike pedal starting of the engine and a clutch with no drag when pedaling for me to be happy with it. This trip was the most dangerous thing I ever done due to car drivers and my speed being much slower than them. That's why I have a motorcycle now, but I would like to solve the drive problem and make it work on diesel. My full size foldup bike with full size 26 inch wheels folds to small carry on luggage. Originally was going to have 2 cycle motor and use a throw away pop bottle for a gas tank to have a carry on motorbike, but airlines say if it ever had gas in the engine it could not fly. 2 cycle has no oil, don't know if I believe them. If anybody wants to go into folding bike business, I'm game to turn over my design, ideas and help at startup for future profit sharing.

[trifan]

So, the electric powered one will fly but a gas powered one won't? Also, electric is safer than gasoline powered on boats and most of the biking around a harbor is well within the range of the electric. As for 2 stroke not needing oil, that is marketing. The gas has the oil in it which lubes the engine as it runs. If you meant that the 2 stroke didn't need any oil added to the gas, then it is a direct injection system which is both more complex and cleaner than a conventional 2 stroke. That cleaner bit is why most of the weedwhackers and other small engines went 4 stroke some time back.

As has been mentioned several times, fossil fuels store lots more energy than batteries, so an electric bike only makes sense in certain applications. Boating would seem to be one.

[med]

Now when these really become readily available and reliable, they will have the potential to be a real game changer:-

Nordic Power Systems | World’s first diesel fuel cell generator | NordicGreen

I have seen efficiencies of up to 40% quoted. Which is as good as you can get out of a decent large sized diesel engine used in a power plant.

A fuel cell capable of producing 20KW - 100KW continuous power at 40% efficiency is just what we need for a long range cruising trawler yacht!

[skipmac]

Originally Posted by denverd0n

Doesn't put them anywhere. I don't think anyone has ever said that electric motors will NEVER be viable in sailing boats. Just that right now the economics don't support it.

They still don't. This announcement doesn't change that. Given time, this may lead to a day when the economics DO support electric motors in sailing boats. I hope so. I really do. But I'm not going to hold my breath, regardless of what some press announcement might say.

Right on the money and echoes my feelings exactly. Electric I think is viable right now IF you are willing to:

a) live with very limited range OR
b) have room for a couple thousand lbs of batteries OR
c) install a diesel generator to power the electric motor AND
d) spend about 3 times the cost of a diesel engine to do it.

I also would really love to go electric but can't justify it based on current technology, the boat I have and my cruising style.

[transmitterdan]

Tesla home unit with 10kWh capacity is $3,500 not $24K. These can help reduce peak demand at home but don't get you off the grid.

[MarkSF]

Yes, it's $3500 for 10kw/h, and $3000 for 7 kw/h.

[TacomaSailor]

Please help me understand what I seem to mis-understand.

I’ve 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 I’ll 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 it’s 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?

[Stumble]

Tacoma,

Your description is pretty much the issue. There is a small market of people who are either ok with a drastically reduced motoring range, or are willing to wait for wind no matter how long it takes. I wish these people well, but I am not one of them.

[jheldatksuedu]

Originally Posted by trifan

So, the electric powered one will fly but a gas powered one won't? Also, electric is safer than gasoline powered on boats and most of the biking around a harbor is well within the range of the electric. As for 2 stroke not needing oil, that is marketing. The gas has the oil in it which lubes the engine as it runs. If you meant that the 2 stroke didn't need any oil added to the gas, then it is a direct injection system which is both more complex and cleaner than a conventional 2 stroke. That cleaner bit is why most of the weedwhackers and other small engines went 4 stroke some time back.

As has been mentioned several times, fossil fuels store lots more energy than batteries, so an electric bike only makes sense in certain applications. Boating would seem to be one.

You don't understand, I'll explain:
When I bike around the harbor, I use the pedal bike, but sometime I feel the need to explore farther, say 100 miles, then I would put the motor on the bike, the 2 cycle engine without the fuel tank would have no liguid, oil or gas. My idea is that you would assemble the bike with motor, pedal to the nearest quik shop, buy a bottle of pop, drink it, walk out to the pumps and pump 14 oz of gas, add 1/4 oz of 2 cycle oil from the small bottle out of your cosmetic case screw the pop bottle onto the pre-made gas cap adapter and motor away with a 30 mile range per tank full. Going farther you might by a 2 liter bottle. When ready to fly home, you throw away the pop bottle and you once again have a motor bike that packs away in a small carry on luggage with no oil or gas contained. Just some fumes, that the airlines say is too much. (I wonder if that is just talk.) My 1500 mile journey was with a 4 cycle weedwacker, it got the 250 mpg, the 2 cycle before that got 330 mpg at 23 mph. Tires lasted much longer with the lower powered 2 cycle.