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Old 09-09-2017, 04:48   #31
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Re: The future of batteries, solar, and electric motors....

Quote:
Originally Posted by hafa View Post
I posted the following points in another thread, but feel it appropriate to repeat them here.

Note that my comments address widespread commercial availability of the technologies under discussion. Micro scale, limited small scale and extravagantly funded projects are exceptions:

First, please note that I own and run a company that does residential solar power design and installation, and our home, business and yacht are all off-grid.

That said, I think that there's a bit too much enthusiasm in general for the potential development and near-term capabilities of solar and battery technology.

Points:
  1. There is a tremendous amount of vaporware in this industry, particularly from research institutions;
  2. The efficiency of commercially available solar panels has improved a whopping 8% in 47 years;
  3. The dominant commercially available battery technology is 160 years old;
  4. The "newest" battery technology (Lithium ion) is 40 years old, and is still not commercially available in the majority of the market;
  5. lifepo4 has seen a boost from the enthusiast sector, but this technology also has limitations and it's unlikely that affordable fully automated charging systems will be widely available in the near-term, thus relegating lifepo4 to niche status for the immediate future.
Although we have seen a tremendous reduction in cost and concurrent increase of availability of panels in the last 8 years due to flooding of the market with inexpensive Chinese units, there is no indication that significant improvements in production or storage technologies for the commercial market are forthcoming.

The upshot?

  1. Energy production and storage density (as observed previously Li-ion is ~1/100th that of diesel by weight) is a tiny fraction of what is required in order to continuously drive a boat using alternative energy alone.
  2. The laws of thermodynamics rule out "perpetual motion" ideas that seem to propagate in these kind of discussions.
Economics is the primary driver for R&D in this area, and the current climate is not conducive to the significant investment required to fully develop breakthrough technologies.
Solar panels were 14% efficient in 1960 and in 2016 were nearly 30% efficient. That's an improvement of around 100%. How do you figure only 8% improvement? Lithium not available for the majority of the market? They sell the batteries at lots of places.
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Old 09-09-2017, 05:05   #32
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Re: The future of batteries, solar, and electric motors....

I have seen an article somewhere about flexible solar panels that are integrated into the sails. This is presently being developed and under testing by a European company.
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Old 09-09-2017, 05:34   #33
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Re: The future of batteries, solar, and electric motors....

Greenline Yachts

Somewhere along these lines?
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Old 09-09-2017, 06:08   #34
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Re: The future of batteries, solar, and electric motors....

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Originally Posted by deluxe68 View Post
Solar panels were 14% efficient in 1960 and in 2016 were nearly 30% efficient. That's an improvement of around 100%. How do you figure only 8% improvement? Lithium not available for the majority of the market? They sell the batteries at lots of places.

Please provide links to nearly 30% efficient, commercially available solar panels. I want to buy some.
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Old 12-09-2017, 12:14   #35
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Re: The future of batteries, solar, and electric motors....

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Originally Posted by deluxe68 View Post
Solar panels were 14% efficient in 1960 and in 2016 were nearly 30% efficient. That's an improvement of around 100%. How do you figure only 8% improvement? Lithium not available for the majority of the market? They sell the batteries at lots of places.
The best commercial panels are closer to 22%; 22-14=8; I suppose I should have worded that as "an improvement of 8%" rather than, "an 8% improvement"; even looking at it as an overall factor, however, it's less than a two-fold increase over a 57 year period. At this rate, 600-watt 77.01 x 39.13 x 1.97" panels will be the norm in the year 2074; incremental improvement at best and still nowhere near the energy production density required for practical marine propulsion.

While Lithium Ferro Phosphate batteries are commercially available, High capacity lithium-ion batteries suitable for home/marine solar power are still very hard to find and are prohibitively expensive. The operating cost of Lithium Ferro Phosphate batteries, however, is exponentially higher than lead acid, even taking into account their somewhat longer service life and better depth of discharge.

Note also that the energy storage density of Lithium Ferro Phosphate is ~200 Wh/L vs lead acid at ~80 Wh/L (mean average), or a 2.5 fold improvement over 160 years (OK, that's a bit skewed, but you get the point). Like panels, the current energy density of the best commercially available technology is nowhere near what is required for practical marine propulsion.

Unless the glacial rate of progress in energy production and storage technology changes dramatically, I think that practical marine electric propulsion on a large-scale commercial basis will not be realized within the lifetime of anyone currently reading this forum.


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I have seen an article somewhere about flexible solar panels that are integrated into the sails. This is presently being developed and under testing by a European company.
As far as solar sails go, please note that the most efficient panels are rigid poly-crystalline silicon. Flexible panels, usually TFT, have far lower production density and service life. Once again, lots of flash-in-the-pan and vaporware technologies have been demonstrated, but never gain sustainable market share for a variety of reasons, including production cost, inability of the technology to scale to mass production and reliability and longevity issues.
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Old 12-09-2017, 18:55   #36
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Re: The future of batteries, solar, and electric motors....

Hybrid via diesel genset, supplemented by solar is currently realistic, but not quite "economically practical".

Quote:
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While Lithium Ferro Phosphate batteries are commercially available, High capacity lithium-ion batteries suitable for home/marine solar power are still very hard to find and are prohibitively expensive. The operating cost of Lithium Ferro Phosphate batteries, however, is exponentially higher than lead acid, even taking into account their somewhat longer service life and better depth of discharge.

energy density of the best commercially available technology is nowhere near what is required for practical marine propulsion.
LiFePO4 or LFP chemistry is one subset of the very general lithium-ion category.

Not at all hard to find, nor "prohibitively" expensive, maybe 5-7 times.

And their cycles lifetime if properly cared for actually make them cheaper than quality lead banks over say decades' timeframe. But yes, expensive up front and therefore too risky for most.

Completely agree on lack of commercial prospect, but not really much more challenging for a hobbyist with funds to spare than the thousands of DIY electric car/truck/bus conversions happening out there.
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Old 13-09-2017, 02:28   #37
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Re: The future of batteries, solar, and electric motors....

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LiFePO4 or LFP chemistry is one subset of the very general lithium-ion category.
Correct, but LiFePO4 has only (roughly) half the energy density of Lithium-ion.

Quote:
Originally Posted by john61ct View Post
Not at all hard to find, nor "prohibitively" expensive, maybe 5-7 times.

And their cycles lifetime if properly cared for actually make them cheaper than quality lead banks over say decades' timeframe. But yes, expensive up front and therefore too risky for most.
Let's look at some examples, taking a ~400 a/h bank @ 48v. For consistency's sake, we'll consider only top-tier manufacturers for each type (prices from here):

8 each Surrette / Rolls S-550 Flooded Battery 6VDC 428Ah: $350 each/$2800.00/7-year warranty=$400 per year.

8 each SimpliPhi PHI 2.6 kWh Lo-Profile Smart-Tech 48v 51.2ah (409.6Ah total): $23560.00/10-year warranty=$2356 per year.

Your estimate of 5 times the cost is about right when applied to annual operating cost, not initial outlay. Also, one needs to factor in the higher cost for charge control systems for LiFePO4 and the ability of lead-acid banks to take more abuse and still function.

Quote:
Originally Posted by john61ct View Post
Completely agree on lack of commercial prospect, but not really much more challenging for a hobbyist with funds to spare than the thousands of DIY electric car/truck/bus conversions happening out there.
That's really the key, right there. Until LiFePO4 systems become competitive, they'll be relegated to niche status. Even then, the significantly different propulsion energy needs of a car/truck/bus VS a cruising yacht are the key factor that will limit the use of batteries, solar, and electric motors for the foreseeable future.
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Old 13-09-2017, 03:53   #38
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Re: The future of batteries, solar, and electric motors....

I wonder how the price of Lithium batteries is going to go in the next year or two and how the comparison to Lead Acid will look.

LIthium just hit an all time high.
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Old 13-09-2017, 04:15   #39
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Re: The future of batteries, solar, and electric motors....

One more issue with Li-batteries is fire hazard. Allright, diesel burns too, but when 400Ah worth of litium ignites just by contacting air, I don't want to be in the half mile radius.
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Old 13-09-2017, 04:39   #40
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Re: The future of batteries, solar, and electric motors....

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First of all, this question is more about the industry 15 years from now. So keep that in mind.

-Lithium batteries are all the rage but the price reflects their infancy in the market.
Lithium is not in it's infancy. They have been standard fare for 2-3 decades. The only new thing is they are cramming a ton of them (litterally) into cars at great expense to get almost acceptable range.
-Solar has been around for years but is taking leaps and bounds now due to interest in alternative power. Size and qauntity of panles vs power output will get better.
Efficiency hasn't changed much. Prices have come down but if you are looking at economies of scale, most of that has already been achieved. At this point the big limitation is not cost but a place to put enough of them to get decent speed. Experimental solar boats kept stripped down and operated with a goal of peak speed...averaged 4-5kts on crossing.
A big cat under sail, should easily beat that when looking at averages.

-Electric motors are swinging deep into mainstream with companies like Tesla, and the like, having a new mass demand to pilot cars. That will translate into marine sooner or later.
Again, electric motors have been incredibly efficient and reliable for 50+ years. The problem with electric motor is storing enough electrons somewhere to power them.

So, as a person who is in his 30's, and a IT engineer, I am wondering if 15-20 years down the road if we could be sitting at a full electric line of Lagoon 450's, for instance, in theory.
I believe they tried that 20yrs back and failed miserably.

Theory?

-Solar power advanced enough to power any realistic power needs between day cycles? If you are talking house loads without air/con,
it's already here. If you are willing to spend, you can even do air/con.
If you want long range propulsion, not in the foreseeable future.

-Advanced wind and motion generators?Wind is another mature technology, you can buy them now. Motion generators sound cool but are of limited use as most sane people anchor or dock where there are little or no waves.
-Boat windows that have solar power elements built in and remain transparent.Price and efficiency will take big hits.
-Electric motors replace diesel engines? I can think of a mountain of pros there when it comes to maintenance and supporting systems, lines, holes in the boat. If there was a cheap reliable way to store the equivalent power a gallon of diesel in the same space and weigh as a gallon of diesel, this would be true...but it's not. Heck even half or a quarter and electric would take over.
-Lithium batteries will be smaller or X times as powerful and lasting than current sized units. (Due to the demand even now for them to become better everyday)As someone else said, lots of vapor ware but actual production batteries haven't gotten more efficient. When they raise the range of electric cars, it's mostly about cramming more batteries into the car (and cutting weight and drag)

In 20 years could we realistically see a full electric line of boats as standard market options?
There are electric boats manufactured now. Most are small to medium size boats for tooling around the harbor at 3-5kts for an hour or two sunset cruise.

Short of a massive technological breakthrough, the only way I see electric drive-trains making up more than a specialty market of a couple percent is if govts prohibit diesel engines in boats.
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Old 13-09-2017, 05:20   #41
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Re: The future of batteries, solar, and electric motors....

What I do see as viable today: A hybrid Cat in the 40' range:

For comparison let's pick a common cruising boat. Say a lagoon 380. Typically has a pair of 30hp diesels (60hp total) and might have a 10kw generator (call it 12hp).

In one hull put, the same generator and a 10kw electric motor and a 5kwh (usable power) battery bank.

In the second hull, put a 45hp diesel with standard drive-train. Combined HP, pretty close to the same at full output.

Also a 1kw solar array mounted on the stern (probably the max you could squeeze on without getting exotic).

Many cruisers in normal conditions only use a single motor while under power so you don't need to assume both motors are running except in certain situations.

Overall cost shouldn't be greatly different. Going from a 30hp to 45hp is not a big cost increase on a new boat and replacing a 30hp with an eletric motor and battery bank should be close to a wash. The generator is already there. Most people already include some solar so that isn't going to be a big increase. I really doubt it would add much but say 5% extra tops. Unlike cars that run 30-40% more, 5% isn't going to scare off a lot of buyers.

Use cases:
- Docking/Maneuvering: You would need to adjust to the difference in response but once learned, it should be just as maneuverable. It's very rare to use full power docking and even when you firewall the throttle, the engine usually doesn't have time to rev up to full speed anyway. The instant torque from zero rpm for the electric motor should largely make up for the lower HP. Net effect, just as maneuverable.
- Cruising at 6-7kts in normal conditions (most common long term motoring situation): Run the 45hp diesel. It's still got plenty of load to get the engine up to temperature and for a cruiser looking for a better drive-train but not willing to give up significant performance, they really won't see any significant difference.
- Quasi-eco mode: For coastal cruising, if you have a 4hr run, set the electric motor at 1kw and use the 45hp for the rest (leaving a 1kw reserve for docking). That will allow slightly lower throttle setting for less fuel burn on the 45hp. The shorter the trip the more battery power you can use.
- Emergency situation (fighting thru a storm or getting an injured passenger to port): Put the 45hp diesel and the electric motor at full throttle and the generator can keep the battery bank up. You can continue as long as there is diesel fuel, same as with the standard drive-train.
- If you are a purist sailor or wanting to reduce your eco-footprint, so you only motor to get to open water: In most conditions, the electric motor can handle the job if you limit your speed to 3-4kts. In fact, the 5kwh battery bank can likely support the motor at say 4kw output for an hour with a 1kwh backup for when you return to port.
- Sunset cruise: If you just want a quiet sunset cruise to no where, set the motor at 2kw output and ghost along at 2-3kts in silence. You have a 2hr range with 1kw in reserve for docking.
- Tacking cheater: If you are struggling thru a tack, it's really easy to just push the leaver forward for a few seconds. Not as good as electric motors on both sides but still doable and far easier than starting a diesel.
- System Trouble: If the electric side fails, the 45hp diesel will leave you with almost no loss of performance, just a bit tricky docking. As good or better than if one of the 30hp diesels fails. If the 45hp diesel fails, you lose speed but can continue on using the generator to keep the batteries up. If both 45hp diesel and generator fail, you still have some range under battery power.
- House Loads at Anchor (no air/con): A 1kw solar array should produce around 5kwh per day and the battery bank can absorb all of it. Without air/con, it's easy to keep up.
- House Loads at Anchor (w/ air/con): With a full battery bank in the evening, turn on the generator for an hour or two to cool the boat. Then switch to battery power. Assuming 10amp @120v and 50% duty cycle, you have around 8.5hrs under battery power, which means no generator running all night...ie: significant reduction in generator fuel usage and not annoying neighbors.
- Maintenance: Possibly slightly lower but not a big difference.
- Resale: It's fully functional, so you aren't scaring off 95% of buyers like a pure electric does.

Savings will depend a lot on how much you are intent you are but if you push hard, you could probably cut fuel consumption by 70-90% of course, if you are careful with regular diesel drive-train, you probably don't use a lot of fuel per year anyway. If you are a normal cruiser, the percentage might only be 10-30% reduction (mostly on generator time) but as the typical cruiser uses much more than the frugal one, that percentage reduction is likely much more in terms of dollars.
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Old 13-09-2017, 06:42   #42
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Re: The future of batteries, solar, and electric motors....

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Correct, but LiFePO4 has only (roughly) half the energy density of Lithium-ion.
But LFP **is** a Lithium-ion.

Which other lithium-ion type are you comparing to, Lithium-Manganese? LiCo?

And since LFP is the only one safe for boats, why compare to anything but lead?
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Old 13-09-2017, 06:44   #43
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Re: The future of batteries, solar, and electric motors....

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One more issue with Li-batteries is fire hazard. Allright, diesel burns too, but when 400Ah worth of litium ignites just by contacting air, I don't want to be in the half mile radius.
LI is a broad catch all.

LFP has little fire danger, IMO less than lead.
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Old 13-09-2017, 06:50   #44
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Re: The future of batteries, solar, and electric motors....

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top-tier manufacturers
...
SimpliPhi
CALB, Winston, GBS & Sinopoly are just fine thanks.

Bare cells + DIY BMS-style protective gear, no auto-balancing, about a grand per 100AH **delivered** and self-installed.

Taken care of well, I'll expect fifteen years with nearly daily cycling, and possibly much more, we just don't know yet.
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Old 13-09-2017, 06:57   #45
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Re: The future of batteries, solar, and electric motors....

I'm glad this post has provoked a good conversation. A lot of future thoughts.

One of my biggest wants in moving over to a Cat with electric motors, putting the math aside for power needs, is replacing a diesel engine with an electric motor. My point being replacing an engine and transmission with hundreds of moving parts, seals, heat, oil+gas etc etc with a much simpler device.

I have rebuilt several petrol engines, and albeit much easier after you knock out a few, I would much rather not have that device spinning a prop than a devie that is much more simpler in design. A couple grease zerks and replace the brushes when they wear down.

I wonder what the efficiency would be, maintenance wise as well, to have 2 electric drive motors to replace the diesel and then have two smaller generators on board to provide power to batteries, along with solar to alleviate the need to run them constantly.

Plus, I'm really for the thought of how much quieter the boat would be. Under normal circumstances you may only need to run the motors for 30 minutes to an hour a day. This should be able to be done without kicking in the generators. For those times you have to raise the iron sail for a few hours, well then you have to deal with the generator noise. Which I would imagine may be much quieter than the diesel engines.
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