Will this replace the Generator onboard?

Wow. this is another amazing item coming from the mind, power and influence of Elon Musk:

Tesla unveils batteries to power homes - BBC News

Could this eventually replace our generators? $3,000 for 7kWh and $3,500 for 10kWh output. Quit possibly!

Dale.

Read the specs more carefully. 7kw capacity or about 600 amp hours at 12 volts. They are rated for 2kw output. Unlike a lead acid, they can be drawn down almost all the way, so you have to take that into consideration when comparing. So lets say equivalent to a 1200 amp hour 12 volt bank? So on a pure cost basis, not there yet, 6 6 volt agm golf cart batteries are about $1100 at Sam's. The advantage looks like that they are much lighter than lead acids for the same capacity (about half), though a weird size (51" tall) for a boat. At 350 volts, not sure what kind of inverter/charger they envision for non-solar use, since it is primarily a solar product perhaps our experienced sun-power folks here will comment.

I don't think so. I already have 8 T105 GC batteries. That is 10.5 kwh and for a lot less than $3,500.

Would the Tesla Battery be cheaper in the long run? I doubt it since I could replace my GC batts 3 times for the price of the Tesla.

I am glad to see that someone is doing something though.

READY2GO said:

I don't think so. I already have 8 T105 GC batteries. That is 10.5 kwh and for a lot less than $3,500.

Would the Tesla Battery be cheaper in the long run? I doubt it since I could replace my GC batts 3 times for the price of the Tesla.

I am glad to see that someone is doing something though.

Click to expand...

Just remember on those Trojans, you can't use all of those kw and have the batteries last. To compare apples to apples, you need to divide that number by approximately two.

Its not that far apart if to take into account:
LA cycling SOC between 50 and 80% to get decent service life/ Tesla has ~90% usable, with service life TBD. You need 2 to 3 times more LA capacity to be equivalent usable KwH.
LA prices are discounted/ Tesla bat prices are probably list.

The problem is adapting the new tech to old 12/24v tech in a boat. They will build inverters to go with the new batteries, but will they be acceptable to use in boats? If there is profit, someone will marinize them.

One thing to consider is that if you have a 600 or 700 AH power source and you can deplete 90% of that is how are you going to charge it backup again in a reasonable time?

Not much use to have a power source that you can deplete in one day, but then it takes 3 days to charge it back up again.

When your boat is running what is the excess power available to recharge the battery and what rate can this battery accept the charge?

I think at least initially the Tesla batteries are intended for intermittent use as backup power supplies instead of a gas or diesel fixed generator. You can use the battery while the power is out and then take your time recharging it once the power is restored.

This technology would be perfect if packaged with a small, 3 kw generator. A 7 kwh, battery could be recharged in 2-3 hours from that size generator. MasterVolt has a 240V, 50Hz unit that does this.

Li batteries can supply a lot of power as well as be recharged quickly. It just takes the right electronics to do it safely.

Such a package would be perfect for running a small, 5,000 btu A/C at night just to cool one cabin.

David

Great input so far lads. I love this type of thought provoking discussion.


Dale.

I keep track of battery technology in a professional capacity. There has been no break-through in any new tech in some time, including Tesla. They are mostly a marketing company that is aiming to create a mass market which could, in fact, drive down the price. Nice packaging. No details. That should tell you something.

windled said:

Wow. this is another amazing item coming from the mind, power and influence of Elon Musk:

Tesla unveils batteries to power homes - BBC News

Could this eventually replace our generators? $3,000 for 7kWh and $3,500 for 10kWh output. Quit possibly!

Dale.

Click to expand...

I don't know about for boats, as others have commented, for boats with generators probably the economics are not there, but I'd like one for my house. We have a 6kwh (24 X 250w) solar array on our house in perfect nor nor west angle (southern hemi remember - sun in northern sky), and with a batt capacity like that, we could go off grid, and then the economics would stack up. I wonder when they might be available in Aus..?

"Such a package would be perfect for running a small, 5,000 btu A/C at night just to cool one cabin."

A couple of Mfg already sell 5000btu DC air cond that are used in large trucks with 4 AGM batts.

The high recharge rate could be used to advantage IF the engine folks allow enough HP to be taken from the front of the engine.

24V -300Amp alts are common in the bus industey , for so many years that rebuilt units are cheap!

Hi All.

I.M.O. Tesla will change the storage battery industry just as Nikola Tesla corrected what Edison got wrong in the past. The Tesla company is coming out with new technology which will change how we use battery power.

As an aside I saw a small note on Facebook about an Aluminium Battery which can be recharged in one minute. Not sure of the details or applications.

I am a big fan of Nikola Tesla and the company which bears his name looks like it will be just as brilliant.

Just in case you are not aware Tesla invented A/C power.

Regards.

David.

It's hard to beat the energy density in a gallon of diesel. That Tesla battery has less than a gallons worth of diesel stored in it. You will have to burn diesel (or gasoline) to recharge the battery anyways. If you don't have a genset, you could use one of these batteries to power a small ac overnight. You would still have to run the engines for hours the next day to recharge the battery.

Even if you had an magic aluminum battery that you could recharge in a minute, you still have to produce that power in a minute to go into that battery. Maybe a 450 kW genset could do it, but I doubt one would fit on any of our boats

The title of this thread and several comments indicates much confusion.

A battery is an energy storage device. It does not produce energy.

A genset is an energy conversion device. It converts diesel into electricity.

A fuel cell is an energy conversion device. It converts hydrogen (or its cousins like methanol) to electricity. You start with hydrogen, methanol, etc. and you get electricity.

There are no energy production devices. There are only energy conversion devices- see the first law of thermodynamics. It still is valid.

David

My take from reading the data and technical reports is that the main use would be in conjunction with solar power as storage banks. The question being how much better at that job than other batteries and at what cost. At present I believe the comination of a generator and well matched battery bank(whatever battery type) is more versatile on a boat.

djmarchand said:

The title of this thread and several comments indicates much confusion.

A battery is an energy storage device. It does not produce energy.

A genset is an energy conversion device. It converts diesel into electricity.

A fuel cell is an energy conversion device. It converts hydrogen (or its cousins like methanol) to electricity. You start with hydrogen, methanol, etc. and you get electricity.

There are no energy production devices. There are only energy conversion devices- see the first law of thermodynamics. It still is valid.

David

Click to expand...

Read this ^^^^^^^ over and over until you understand.

Some of the new battery technologies do offer some very interesting properties for boaters, but they have nothing to do with replacing a generator.

"Nikola Tesla corrected what Edison got wrong in the past"

Edison got LOCAL distribution wrong , his DC 100+ years ago required a power station every mile or so,

BUT today long distance power distribution is returning to DC , a switching gear gets cheaper.

A single DC cable can better replace towers with strung wires to move juice many hundreds of miles.

FF said:

"Nikola Tesla corrected what Edison got wrong in the past"

Edison got LOCAL distribution wrong , his DC 100+ years ago required a power station every mile or so,

BUT today long distance power distribution is returning to DC , a switching gear gets cheaper.

A single DC cable can better replace towers with strung wires to move juice many hundreds of miles.

Click to expand...

High voltage DC is growing rapidly worldwide, especially in China, because it can move enormous amounts of electricity, as you say Fred, very long distances. It also can make electricity flows more controllable compared to AC transmission. It has been less popular to date in North America with the exception of a handful of projects primarily in the western US and Canada.

Back to the OP's original theme: the Tesla PowerWall provides 7-10kW of storage using, I think, cleverly managed & pre-configured Lithium Ion batteries. We know one of the big advantages of that technology is that it can be re-charged super fast relative to conventional battery technologies.....so less engine/alternator run-time, reduced genset run-time and/or greater efficiency (and so a potentially greater contribution) from onboard solar panels. So it seems to me one question is simply around cost. Is the Tesla offering of 7-10kW for $3000-$3500 cheaper than buying the equivalent storage in a bank of Li Ion batteries?


Tesla has powered with an Israeli firm, SolarEdge, to provide inverters.


(Peter: available in Australia from mid-2016. You can order now with no $ down and no commitment)

Good points, and good questions. I agree that the various Li battery technologies offer some great features for boats. These are:

1) Fast recharge rates. I actually think this doesn't really matter in most cases because our charging systems are typically the limiting factor, not the batteries - at least when they are bulk charging...

2) No tapered absorption phase. I think this is the really significant advantage for recharging. The Li batteries can take pretty much full charge current right up until they are full. I think this is a really big deal for boats and allows us to make much better use of our generators and engine alternators.

3) The ability to draw down the battery by 80% or more instead of 50%. This too is quite significant, allowing batteries to be sized about 20% larger than your expected needs instead of 2x as we need to do today with lead acid batteries.

As for your cost question, let's assume the Tesla battery bank will be 7kwh and cost $3500. That's $500/kwh. 80% of it is usable, so that's $625 per usable kwh.

An AGM 8D battery is about $700 and contains 2.7kwh (225ah x 12v). But only 50% of it is usable, so it ends up costing $518 per usable kwh.

Those costs are actually pretty close, and well worth the advantages. But it doesn't take into account the charge control systems needed to properly handle the Li batteries, so it's not a comprehensive comparison, but still an very interesting data point.

There is another aspect of storing power in a battery that we seldom pay attention to, and that's the cost per kwh to store power. It costs some significant $$ for a battery bank, and that bank is good for about 1000 cycles. Then you need to replace it. When you look at how many kwh you can store and retreive in that 1000 cycle lifetime, you come up with a cost per kwh of stored power. We pay attention to the cost to generate power running our generators, but typically ignore the cost to store that power. So let's take a look.....

That 8D AGM battery in my previous post costs $518 per kwh of storage capacity. It can be cycled 1000 times in its lifetime, yielding a cost of $0.518 per kwh to store power. That's a lot, and it's in addition to the cost to generator it if you run a generator.

T/tree: all good points. Some other comments on the Tesla PowerWall specifically:
1. must be wall (bulkhead) mounted, presumably because of its "liquid thermal control" mechanism. So this otherwise space-efficient packaging cannot be laid flat or on its side...but I wonder how it would cope with the movement (pitch,roll, yaw) of our vessels?
2. max draw is 2kW..(with a surge capacity of 3.3kW) .so around 18A if you are on the North American 110v system or around 8.5A if you are rest-of-world on 220-240v. That's just enough to run one 12kBTU air-con unit but I think more typically, would be used to supply the non-air con demands via an inverter. A genset would still be used to run air-con (but could be fully loaded to recharge the PowerWall)
3. Operating range is -4F -- 110F (-20C -- 43C). That would make risky engine room installations for those of us in tropical, sub-tropical and even temperate (Summer) locations...and have Winter-izing implications for those in colder climes
4. The advertised price before install costs works out at $250kWh according to Tesla reviewers...that's about 25% of the current typical pricing of Li-chemistry batteries. They are clearly trying to build a mass/consumer market and with volume and low margins, so the unit prices are low. Maybe its big benefit for boaters will be to change the whole pricing game for this battery technology, as the Chinese did with solar panel costs
5. Some reviewers indicate 5,000 cycles might be conservative. If $400per kWh installed and 80% efficient, that's around 15c/kWh storage cost.


A couple of reviewing sites, from both technical & economic perspectives:


Why Tesla's Powerwall Is Just Another Toy For Rich Green People - Forbes


Tesla Powerwall: A Battery For Your Home | Gizmodo Australia

The Tesla powerwall is getting some press here. I wonder, re bolting one to the house, if the Li-ion fire risk has been resolved.
We had a new Tesla for an airport transfer in Amsterdam. Stunning car, electric or not, accelerates as if attached to a retracting elastic strap.

So my friend and his wife went to Italy. On his birthday, his wife gave him a small gift wrapped box. Inside was a picture of a stunning new Tesla that she bought him for his birthday. That car is awesome. I think I have a well off friend.

hmason said:

So my friend and his wife went to Italy. On his birthday, his wife gave him a small gift wrapped box. Inside was a picture of a stunning new Tesla that she bought him for his birthday. That car is awesome. I think I have a well off friend.

Click to expand...

I was thinking he was getting boat shoes when I started reading, but then read tesla... Kind of a boring present when compared to a nice pair of boat shoes....