Hybrid Theory

[Lake-Effect]

Originally Posted by Andrew Troup

I'd be interested to know why, four years after the interim Hymar report (which took 18 months) it seems there are no actual results to report

They reported. Scroll up to pdf27's post for the link.

The main theoretical efficiency of a hybrid system is that combustion engines are most efficient over a narrow part of their range, and that it's easier to produce a combustion engine that mainly runs in that narrow band... ie a generator.

A mid-sized boat is likely to have both a propulsion engine, and a generator. If the boat had electric drive, then the boat could have two identical generators, which is a useful redundancy. Another advantage to hybrid systems is that you can locate the combustion engines where it most makes sense weightwise in the boat, which isn't always at the inboard end of the propshaft.

But it's pretty clear that for the cruiser who expects to do days of nonstop motoring, the simple diesel is the most practical and efficient propulsion right now. And that's... most cruisers.

Better batteries will help make electric or hybrid auxiliary power more popular. Electric autos will hopefully drive this development, and bring the price down.

[Andrew Troup]

Originally Posted by Lake-Effect

They reported. Scroll up to pdf27's post for the link.

Hmm, that's where I went before posting. The only link in the body text took me to this:

Mid-term summary report v2

Work on the HYMAR project in the first 18 months

It doesn't contain any useful data, or even a date, but it talks of dates in 2011 as being in the future.

Under "Documents and Data" The only reported data I could find was in the London Boat Show report from January 2010

Under "Hymar Update" there's some promo material which starts

July 2012:

In this final phase of the HYMAR project, the international team have been tasked with putting the previous three years’ theory into practice. EU projects are split into three broad phases: research; development and validation and HYMAR is now in the validation phase. The project will complete at the end of September 2012.

I see no final report, and no data since January 2010, hence no validated data.

Does anybody have a link to the actual final report, because frankly the home page is a confusing, uninformative and cryptic place.

[Stumble]

Lake effect,

That's a nice theory, but it misses a serious problem.

A mid size cruiser will have two Diesel engines, a large propulsion engine and a generator. If these were close to the same size then it might work to split the combined power in half and install two engines the same size. But that isn't what happens. What is actually installed is a 40kw propulsion motor and a 5kw generator.

If you tried to split them in half you wind up with two 22kw generators. Which means when you are just running house loads you still have to drive a very large generator of which you only need a small amount of power. Of course there is plenty of power to get in and out of a harbor, but not enough to approach full speed.

The solution is to run all of the house loads from a battery bank and just use the generator to recharge the batteries... But what size battery bank and charging system do you need in order to absorb all of the power from a 22kw generator? And even using the best batteries on the planet regardless of cost you are talking about a huge amount of weight and volume dedicated to batteries.

[pdf27]

Originally Posted by Lake-Effect

The main theoretical efficiency of a hybrid system is that combustion engines are most efficient over a narrow part of their range, and that it's easier to produce a combustion engine that mainly runs in that narrow band... ie a generator.

The problem is, that narrow band happens to be at something like 1200 revs and with the engine heavily loaded - which means it'll be loud, heavy and with limited life. Unless or until we get small, efficient gas turbines available as generators (see the other thread I have on this here), I don't think this will change.
That's a large part of the reason HYMAR shifted to parallel hybrid - that means they can do generation by adding a bit of load to a running engine, rather than running a dedicated engine. That saves weight, cost, and is still a bit more fuel efficient than a dedicated generator in most cases since the average fuel efficiency of the engine will improve a bit by adding load. They did have Steyr build a suitable high-efficiency generator but decided it was simply unmarketable, suggesting it was a bit of a beast.

The main difference in my suggestion is focussing more on the areas where a combustion engine is really inefficient and offering an alternative way of doing it mechanically which **should** offer some gains in efficiency and possibly reliability too.

Originally Posted by Stumble

Lake effect,

That's a nice theory, but it misses a serious problem.

A mid size cruiser will have two Diesel engines, a large propulsion engine and a generator. If these were close to the same size then it might work to split the combined power in half and install two engines the same size. But that isn't what happens. What is actually installed is a 40kw propulsion motor and a 5kw generator.

If you tried to split them in half you wind up with two 22kw generators. Which means when you are just running house loads you still have to drive a very large generator of which you only need a small amount of power. Of course there is plenty of power to get in and out of a harbor, but not enough to approach full speed.

The solution is to run all of the house loads from a battery bank and just use the generator to recharge the batteries... But what size battery bank and charging system do you need in order to absorb all of the power from a 22kw generator? And even using the best batteries on the planet regardless of cost you are talking about a huge amount of weight and volume dedicated to batteries.

For some very rough calculations, LiFePO4 batteries can accept charge at 1C and weigh ~10 kg/kWh. So call it 550 lbs and a space roughly 20 x 15 x 5 inches for a battery bank capable of being charged by a 22kW generator. Lots of weight and cost (about $15,000 if I've done my sums right), but you certainly won't be running the generator very often - that amount of storage would enable me to run my bricks-and-mortar house for 3 days straight!

The more I think about it, the more a serial hybrid design like that only makes sense for someone who basically wants a floating RV - occasionally moves from place to place, but mostly sits at anchor or a mooring with all the comforts of home. At least then they don't run their generator all the time and irritate everyone else nearby.
If you're sailing everywhere for long distances the ability to generate a lot of house power by regeneration is probably also pretty beneficial - induction hobs rather than propane for instance are probably safer, and keeping more of your fuel in reserve in case you need to run the engine to get somewhere in a hurry rather than using it to run the alternator has to be beneficial too.

Edit: I may be excessively optimistic about power to weight ratio - that weight number is quoted from Wiki, but places actually selling them seem to quote rather heavier batteries for the same useful delivered power.

[Greggegner]

As soon as the budget allows I will be adding about 5 kW of co-generation for the following reasons:

1. Charge my batteries while sailing - Auto and the frig eat power
2. Back up power if diesel fails - ever have a diesel fail at a bad time. My last one was an impeller coming into a tight harbor with 25 knots of wind. Imagine flip a switch and 3-4 knots to the dock.
3 . Good use of limited space

Not cheap I think less than the 9k someone quote, but not much.

[Maine Sail]

Originally Posted by pdf27

For some very rough calculations, LiFePO4 batteries can accept charge at 1C and weigh ~10 kg/kWh. So call it 550 lbs and a space roughly 20 x 15 x 5 inches for a battery bank capable of being charged by a 22kW generator. Lots of weight and cost (about $15,000 if I've done my sums right), but you certainly won't be running the generator very often - that amount of storage would enable me to run my bricks-and-mortar house for 3 days straight!

.3C -.5C charging of LFP is what is normally recommended for regular charging by most prismatic cell makers including Winston, CALB etc... Beyond that where are you going to source chargers to feed a bank like that a 1C charge current, even if you could..... ??

BTW I worked on a lobsterboat two months ago that has 28,000 hours on a 26 year old Cummins diesel, and it has never been rebuilt....

I set foot on lots of commercial vessels with 10K + hours on the engines. It would take a pleasure boater two lifetimes to hit 10k engine hours......

Hell our own diesel is approaching 4k hours and purrs like a kitten. It has never been rebuilt either........

[Hyprdrv]

On Electra Glide I have 1 generator. That generator is 16kw with a veriable output at 144V/174V DC, my main bank of batteries is set for this. From there the voltage is dropped through a 144V to 12V charge/converter for the house bank. As the demand increases for the house the the propulsion bank charges the house bank. At a distribution box the power from the generator is sent to either charge the 144V bank or run the E-motors. Power also has the ability to go to an inverter to step from 144V DC down to 120V AC again from the Generator if running or the main propulsion bank if it's not running.

PDF said,
"For some very rough calculations, LiFePO4 batteries can accept charge at 1C and weigh ~10 kg/kWh. So call it 550 lbs and a space roughly 20 x 15 x 5 inches for a battery bank capable of being charged by a 22kW generator. Lots of weight and cost (about $15,000 if I've done my sums right), but you certainly won't be running the generator very often - that amount of storage would enable me to run my bricks-and-mortar house for 3 days straight!"

LiPo can except charge rates as high as 10C and higher as was tested by Jack Rickard. In fact they have been hit much higher, (Don't try this at home)

I'm not sure I understand your calc on the weight but 48 of these puppies giving me 144V pack weighs 550lb. Most smaller sailboats will probably only run a 72V system so figure about half that weight.

My new pack will run $9,000 today (50 cells) again figure 1/2 that for a 72V system.

If I had it to do from the start I would like a 20KW genset for the 144V system (80A max for the motors) and have plenty to run the charger at 2C which I can't at this time.

Just because you can doesn't mean you should. I still ask the wife to shut off stuff when not used and now plan a couple solar panels for the house bank to remove the load off the propulsion bank. There just isn't anything out there without covering the boat in panels to charge a 144V system (yet). With the system now I can get 5 days of house use on the hook without starting the genset. By the way my genset is an HLF from Germany with a sound incloser, it's quite.

The genset has variable output. I can manually reduce the load as needed there by reduce the amperage to go to a trickle charge. This is one of the things that Lagoon on the 420 tried to automate early on and didn't work giving them fits.

As a side note when sailing all I here is a noisy vent/exhaust fan on the starboard side. It's actually come in handy when docked to remind me the motors are still on.

Steve in Solomons MD

[Greggegner]

Would love all electric....but two generators way to much...

[SV Windrush II]

After reading some of these posts, I have decided I will wait until technology advances more on the battery charging side of things before I switch to electric drive system because of the following.

1. If I need to run a generator to charge batteries to run my electric motor. That sounds very inefficient to me.
2. To me, the whole concept of using electric power is to get away from combustion engines altogether. Im not excitted about having a ton (Literaly) of batteries in my sailboat.
3. Batteries are very toxic to make and toxic to get rid of. and of course as mentioned earlier in this thread, very hazardous onboard if anything bad should happen. The electric motor may be clean, but the batteries powering it definitely are not if you conciser a batteries life-cycle, which most people don't. they just look at it as while they are using them. (If you go to either a battery manufacturing plant or re-cycle plant you will know what I'm talking about).

4. Cost prohibitive. I have a 48' 24 ton sailboat. I would need to spend $20k +++ to get set up. yikes! Wait... that doesn't even include a generator to charge everything which I do not plan on having, since I will have solar, wind machines and a motion generator.

[Lake-Effect]

Originally Posted by pdf27

The problem is, that narrow band happens to be at something like 1200 revs and with the engine heavily loaded - which means it'll be loud, heavy and with limited life.

That's not true by a long-shot. An engine that's designed to run at a particular load and RPM will run best and longest at that load! I believe more boat diesels have a short life from NOT being run harder or often enough.

... HYMAR shifted to parallel hybrid - that means they can do generation by adding a bit of load to a running engine, rather than running a dedicated engine. That saves weight, cost, and is still a bit more fuel efficient than a dedicated generator in most cases since the average fuel efficiency of the engine will improve a bit by adding load.

I think we all now agree (HYMAR too) that the usual direct propulsion combustion motor isn't going away any time soon. For the cruiser who sometimes needs to make passages by motor, it's still the best option.

Originally Posted by Stumble

A mid size cruiser will have two Diesel engines, a large propulsion engine and a generator. If these were close to the same size then it might work to split the combined power in half and install two engines the same size. But that isn't what happens. What is actually installed is a 40kw propulsion motor and a 5kw generator.

If you tried to split them in half you wind up with two 22kw generators. Which means when you are just running house loads you still have to drive a very large generator of which you only need a small amount of power. Of course there is plenty of power to get in and out of a harbor, but not enough to approach full speed.

The charging load would depend on the battery bank size, and maximum safe rate of charge. With today's batteries, your point is valid. Maybe Dan317's suggestion of "Electric motor drives the yacht under power, and you have two generators. One large, 30KW one small 10KW. " ...is a better idea.

(Mr Troup - sorry for the misunderstanding. I found this, from July 2012, and here's their website. I also found a sort of summary which suggests the numbers are being crunched for publication, and also that some patents were being applied for. That would go a long way towards explaining the delay)

[Hyprdrv]

Lie said:
"
After reading some of these posts, I have decided I will wait until technology advances more on the battery charging side of things before I switch to electric drive system because of the following."

No one (at least not me) is trying to talk anyone into switching to EB (Electric Boating) I have the system and it works for me. I also know it will work on long distance cruising so since I plan on the Carib. at a future date I'll let you know how it goes.

But let's make some assumptions. You own a sailboat and you want to sail first and motor second. Your out in the middle of nowhere and run out of dino fuel. Now what?
I could get my electric system up and running, granted it would take time and patience but I could move the boat with electricity from the sun or wind.
(Ok you could squeeze a bunch of fish for fish oil)

1. If I need to run a generator to charge batteries to run my electric motor. That sounds very inefficient to me.

The genset is used to EXTEND the run time of the motors. If I have an 8 hour trip and no wind I need to run the Genset for 4 hours to charge and power the motors.

2. To me, the whole concept of using electric power is to get away from combustion engines altogether. I'm not excited about having a ton (Literally) of batteries in my sailboat.

I posted some realistic weights previously. Depending on which bats your using the Li's will be 25% of that "ton".

3. Batteries are very toxic to make and toxic to get rid of. and of course as mentioned earlier in this thread, very hazardous onboard if anything bad should happen. The electric motor may be clean, but the batteries powering it definitely are not if you conciser a batteries life-cycle, which most people don't. they just look at it as while they are using them. (If you go to either a battery manufacturing plant or re-cycle plant you will know what I'm talking about).

You really need to study up on LiFePo4's. They are some of the cleanest batteries out there. Take a look at the "LiFePo4's for house banks" Posting and search on the web. The Li's are NOTHING like a lead acid other than provide Electricity.

4. Cost prohibitive. I have a 48' 24 ton sailboat. I would need to spend $20k +++ to get set up. yikes! Wait... that doesn't even include a generator to charge everything which I do not plan on having, since I will have solar, wind machines and a motion generator.

Cost is subjective.
Good for you, on a boat that size and no genset is quite a feet. My wife wouldn't step foot on it but again that's subjective. What happens when the sun and wind go away for a few days out there?

Let's not forget that this thread was suppose to be somewhat about theory and I always love talking about my boat.

Steve in Solomons MD

[SV Windrush II]

Originally Posted by Hyprdrv

Lie said:
"
After reading some of these posts, I have decided I will wait until technology advances more on the battery charging side of things before I switch to electric drive system because of the following."

No one (at least not me) is trying to talk anyone into switching to EB (Electric Boating) I have the system and it works for me. I also know it will work on long distance cruising so since I plan on the Carib. at a future date I'll let you know how it goes.

But let's make some assumptions. You own a sailboat and you want to sail first and motor second. Your out in the middle of nowhere and run out of dino fuel. Now what?
I could get my electric system up and running, granted it would take time and patience but I could move the boat with electricity from the sun or wind.
(Ok you could squeeze a bunch of fish for fish oil)

1. If I need to run a generator to charge batteries to run my electric motor. That sounds very inefficient to me.

The genset is used to EXTEND the run time of the motors. If I have an 8 hour trip and no wind I need to run the Genset for 4 hours to charge and power the motors.
2. To me, the whole concept of using electric power is to get away from combustion engines altogether. I'm not excited about having a ton (Literally) of batteries in my sailboat.

I posted some realistic weights previously. Depending on which bats your using the Li's will be 25% of that "ton".

3. Batteries are very toxic to make and toxic to get rid of. and of course as mentioned earlier in this thread, very hazardous onboard if anything bad should happen. The electric motor may be clean, but the batteries powering it definitely are not if you conciser a batteries life-cycle, which most people don't. they just look at it as while they are using them. (If you go to either a battery manufacturing plant or re-cycle plant you will know what I'm talking about).

You really need to study up on LiFePo4's. They are some of the cleanest batteries out there. Take a look at the "LiFePo4's for house banks" Posting and search on the web. The Li's are NOTHING like a lead acid other than provide Electricity.

4. Cost prohibitive. I have a 48' 24 ton sailboat. I would need to spend $20k +++ to get set up. yikes! Wait... that doesn't even include a generator to charge everything which I do not plan on having, since I will have solar, wind machines and a motion generator.

Cost is subjective.
Good for you, on a boat that size and no genset is quite a feet. My wife wouldn't step foot on it but again that's subjective. What happens when the sun and wind go away for a few days out there?

Let's not forget that this thread was suppose to be somewhat about theory and I always love talking about my boat.

Steve in Solomons MD

Thanks for the input Steve. You got me thinking and I will do more research on the batteries

[appick]

[QUOTE=Hyprdrv;1522061]Lie said:
"
After reading some of these posts, I have decided I will wait until technology advances more on the battery charging side of things before I switch to electric drive system because of the following."
But let's make some assumptions. You own a sailboat and you want to sail first and motor second. Your out in the middle of nowhere and run out of dino fuel. Now what?
I could get my electric system up and running, granted it would take time and patience but I could move the boat with electricity from the sun or wind.
(Ok you could squeeze a bunch of fish for fish oil) "

... then the wind dies on a cloudy day!

1) You probably should've planned better if you needed to motor that far and what your fuel usage should be, or just sailed more and saved the fuel .

2) If you had a IC engine you probably wouldn't also have electric propulsion

3) If you're out far enough where you ran out of fuel the 4-8hrs at 3-6knts on the electric isn't really going to get you anywhere it seems.

4) Yes you could move the boat with electric propulsion and solar/ wind charging. However you'd be talking about a few nautical miles a day one would think that fighting tides/currents/wind it wouldn't be able to keep up. I know that large solar ship just crossed the Atlantic but I bet you don't have that many solar panels.

The other comments about batteries I understand. You can't determine the quality of material what the mfg uses when built. I guess my point with that was for the $9k spent in just replacing batteries I could have a diesel that will last for 10-20 years with average use. I doubt very much that lots of the controlers, chargers, inverters, and batteries with age will last that long in a marine environment.

150,000 hrs theoretical run time on electric motors is just that, theoretical. Yes eletric motors are easy to rebuild no doubt there. Although for me so is a diesel. Any who back to theory...

If/when they get battery energy density up to say 40-50% as they are talking about with different materials I keep reading about in science journals in the super capacitor/ batteries, then we'll really have something! That along with carbon fiber nano tubes being used in a single layer to trap photos on top solar cells and boosting their effeciency I can see some potentially sweet things coming our way! Not just for boats either.

[appick]

I could be wrong, but last I heard there was no recycling for lipo batteries either.

[Stumble]

Let's just be clear, Beneteau (my he owner of Lagoon) spent a huge amount of money and time bringing the electric catamarans to the market. Eventually they walked away from the technology because they couldn't get it to work within the expectations of their customers.

I do think it is something that will occur, but better battery technology is crucial for it be hit mainstream. I actually had a 30' sailboat with an electric motor and loved it, but I never needed to go more than a few hundred yards with it.

In a nut she'll here is the problem...
...................energy..........by
...................density..........volume
Diesel...........46.7MJ/kg.....37.3MJ/L
LifePo.......... .875MJ/kg.. 2.63MJ/L

No current electrical storage capability we have can even come close to the energy density of liquid fuels.