First Boat-Hybrid or not?

[Sea Dog]

1 minute ago, cuthound said:

 

Between us we can actually write stuff that makes sense. Unfortunately it seems we are unable to do this individually. ?

I'm not so sure about collectively either CH, but it'd be a fun evening in the pub, eh? 

[IanD]

55 minutes ago, cuthound said:

 

Whilst thermal efficiency increases with load i have yet to see any diesel than consumes less fuel with more load, and I have commissioned hundreds of them.

 

Admittedly these were in standby generators, where the engine has to run at a constant speed, so pumping losses are constant, but the diesel engines of canal boats operate over a very limited speed range compared to say the engines in motor vehicles.

It's more efficient to run an engine at higher power for a fraction of the time (also charging batteries) and use electric power to fill in the gaps -- see attached spreadsheet for an example with a Beta 43. At all revs except close to maximum there's a lot of "spare" power available above that absorbed by the prop.

 

Running all the time with 4hp to the prop at 1400rpm consumes 1.5l/hr, engine is running at about 15% of maximum power at these revs so thermal efficiency is about 19% (compared to 34% at full power and load, 43hp at 2800rpm). With a generator absorbing another 10bhp engine consumption will be about 3.5l/hr with about 28% efficiency, but it only has to run for one hour in three (the 10hp into generator for 1 hour comes back from the motor as 4bhp for 2 hours assuming 80% efficiency) so average consumption is 3.5/3=1.2l/hr, giving about 20% saving in fuel.

 

This also shows that a 10hp/7.5kW generator is really too small for a Beta 43, the engine has 15hp/11kW "spare" available all the way from 1000rpm to 2400rpm, with 20hp/15kW available at a 1400rpm cruise -- a bigger generator would give bigger fuel savings by running the diesel at higher efficiency/power for even shorter times.

53 minutes ago, peterboat said:

Hydrogen has been on the cusp for years and unlike batteries really isn't practical for many reasons chief of which is its just not safe in normal life.  No doubt when the first major explosion occurs it will die of for say another hundred years or so 

The main problem with hydrogen is not safety, it's lousy efficiency -- it's acting as an energy storage medium like batteries, except that the overall "power station to wheel" efficiency is about half so needs double the amount of energy. Given efforts to minimise energy consumption, this makes a nonsense of the idea...

[ditchcrawler]

11 hours ago, nicknorman said:

Point 1 how do you know this? Eu rules, but aren’t we leaving?

 

 

Are you sure, I'm not. The UK wont leave without a deal, the EU wont agree to a deal that suits the UK

[peterboat]

2 hours ago, Sea Dog said:

Hydrogen doesn't just occur either; it needs making. Mostly it's from natural gas or petrochemical sources, but even the tiny bit made by electrolysis needs energy, and quite a lot of it... which ain't coming from hydrogen. 

I was reading that it takes rather a lot more energy to make hydrogen than it does electricity to charge a car. The figures were interesting to say the least, that and the safety issues for me and most of the car industry makes hydrogen a bit of a non starter 

 

[peterboat]

1 hour ago, IanD said:

It's more efficient to run an engine at higher power for a fraction of the time (also charging batteries) and use electric power to fill in the gaps -- see attached spreadsheet for an example with a Beta 43. At all revs except close to maximum there's a lot of "spare" power available above that absorbed by the prop.

 

Running all the time with 4hp to the prop at 1400rpm consumes 1.5l/hr, engine is running at about 15% of maximum power at these revs so thermal efficiency is about 19% (compared to 34% at full power and load, 43hp at 2800rpm). With a generator absorbing another 10bhp engine consumption will be about 3.5l/hr with about 28% efficiency, but it only has to run for one hour in three (the 10hp into generator for 1 hour comes back from the motor as 4bhp for 2 hours assuming 80% efficiency) so average consumption is 3.5/3=1.2l/hr, giving about 20% saving in fuel.

 

This also shows that a 10hp/7.5kW generator is really too small for a Beta 43, the engine has 15hp/11kW "spare" available all the way from 1000rpm to 2400rpm, with 20hp/15kW available at a 1400rpm cruise -- a bigger generator would give bigger fuel savings by running the diesel at higher efficiency/power for even shorter times.

The main problem with hydrogen is not safety, it's lousy efficiency -- it's acting as an energy storage medium like batteries, except that the overall "power station to wheel" efficiency is about half so needs double the amount of energy. Given efforts to minimise energy consumption, this makes a nonsense of the idea...

You know that and I know that but for some hydrogen is the most expensive waste of time ever! Eventually they will get it, after all it's only 90 years since the last big bang 

[johnmck]

Ten years or so ago, just before our boat was in build, I was all for a hybrid system. Even consulted Fischer Panda. The costs did not stack up , nor did the technology available. 

I would love an all electric boat. But again, the technology and infrastructure negates this option. How do you cruise, produce heating and hot water in the depths of winter Peterboat? I suspect you do not and there be the problem. Yes, you can bridge hop in the summer months, but the rest of the year?

Hybrid systems provided a good feel alternative, but not a solution.  And they cost...

[matty40s]

4 hours ago, johnmck said:

Ten years or so ago, just before our boat was in build, I was all for a hybrid system. Even consulted Fischer Panda. The costs did not stack up , nor did the technology available. 

I would love an all electric boat. But again, the technology and infrastructure negates this option. How do you cruise, produce heating and hot water in the depths of winter Peterboat? I suspect you do not and there be the problem. Yes, you can bridge hop in the summer months, but the rest of the year?

Hybrid systems provided a good feel alternative, but not a solution.  And they cost...

Agree entirely John, I was looking at a hybrid a couple of weeks ago, all singing and dancing 11kv genny to massive battery bank, brushless electric drive, but they had removed the solar panels to stick on their camper van. I tried to explain the stupidity of the action when selling an electric drive boat, but it didnt register.

[Murflynn]

8 hours ago, johnmck said:

.....................Yes, you can bridge hop in the summer months, but the rest of the year?

 

I hope you mean bona fide continuous cruising.  

[Athy]

19 hours ago, nicknorman said:

Yes they have - but they are no acting on it instantly,

How can I tell that you live in Scotland?

21 hours ago, peterboat said:

 its happened,  red diesel is history for propulsion on boats.

!

No, it has and is not - at least, not when I filled our boat's tank with red diesel just over a week ago.

[nicknorman]

9 minutes ago, Athy said:

How can I tell that you live in Scotland?

Is it because the correspondingly great distance between me and CWDF computer servers down in Englandshire means that occasionally, letters get lost in transit?

[cuthound]

11 hours ago, IanD said:

It's more efficient to run an engine at higher power for a fraction of the time (also charging batteries) and use electric power to fill in the gaps -- see attached spreadsheet for an example with a Beta 43. At all revs except close to maximum there's a lot of "spare" power available above that absorbed by the prop.

 

Running all the time with 4hp to the prop at 1400rpm consumes 1.5l/hr, engine is running at about 15% of maximum power at these revs so thermal efficiency is about 19% (compared to 34% at full power and load, 43hp at 2800rpm). With a generator absorbing another 10bhp engine consumption will be about 3.5l/hr with about 28% efficiency, but it only has to run for one hour in three (the 10hp into generator for 1 hour comes back from the motor as 4bhp for 2 hours assuming 80% efficiency) so average consumption is 3.5/3=1.2l/hr, giving about 20% saving in fuel.

 

This also shows that a 10hp/7.5kW generator is really too small for a Beta 43, the engine has 15hp/11kW "spare" available all the way from 1000rpm to 2400rpm, with 20hp/15kW available at a 1400rpm cruise -- a bigger generator would give bigger fuel savings by running the diesel at higher efficiency/power for even shorter times.

The main problem with hydrogen is not safety, it's lousy efficiency -- it's acting as an energy storage medium like batteries, except that the overall "power station to wheel" efficiency is about half so needs double the amount of energy. Given efforts to minimise energy consumption, this makes a nonsense of the idea...

 

Interesting.

 

I wonder what kind of boat they used? A 22"x13" prop is pretty big for the kind of narrowboat that would use a Beta 43 and 2800rpm is unacheivable on most canals.

[peterboat]

9 hours ago, johnmck said:

Ten years or so ago, just before our boat was in build, I was all for a hybrid system. Even consulted Fischer Panda. The costs did not stack up , nor did the technology available. 

I would love an all electric boat. But again, the technology and infrastructure negates this option. How do you cruise, produce heating and hot water in the depths of winter Peterboat? I suspect you do not and there be the problem. Yes, you can bridge hop in the summer months, but the rest of the year?

Hybrid systems provided a good feel alternative, but not a solution.  And they cost...

I don't cruise in winter, I never have even though I have a wheelhouse. I have a Rayburn and whispergen for heating and if I am short on domestic power.  We do go out if it's sunny in the winter for a weekend, but as we are on a river which can flood rapidly we are careful, all this is the same as when it was diesel. 

[Sea Dog]

46 minutes ago, cuthound said:

 

Interesting.

 

I wonder what kind of boat they used? A 22"x13" prop is pretty big for the kind of narrowboat that would use a Beta 43 and 2800rpm is unacheivable on most canals.

I'd be surprised if a Beta 43 could swing a prop that big at 2800 rpm in any depth of water. Anyone running that size?

[cuthound]

13 minutes ago, Sea Dog said:

I'd be surprised if a Beta 43 could swing a prop that big at 2800 rpm in any depth of water. Anyone running that size?

 

As you say its a very big prop for a Beta.

 

I'm in the process of changing my 17"x11" for an 18"x12" on my 60 foot narrowboat, which will hopefully improve my stopping power and reduce the cruising revs.

[peterboat]

15 minutes ago, Sea Dog said:

I'd be surprised if a Beta 43 could swing a prop that big at 2800 rpm in any depth of water. Anyone running that size?

3 to 1 gearbox?

[Sea Dog]

10 minutes ago, peterboat said:

3 to 1 gearbox?

Ah yes, I was just thinking of the typical 2:1 narrowboat set up, but thats not really the case here at all, is it. All a bit too complicated for generic narrowboat propulsion imho, but that's not a criticism of your own electric set up Peter which I admire and seems to work well for your own cruising needs.

[peterboat]

2 hours ago, Sea Dog said:

Ah yes, I was just thinking of the typical 2:1 narrowboat set up, but thats not really the case here at all, is it. All a bit too complicated for generic narrowboat propulsion imho, but that's not a criticism of your own electric set up Peter which I admire and seems to work well for your own cruising needs.

I can take criticism easy enough when it's justified, this weekend I am picking up a much larger battery bank to extend my cruising range. Also more solar and a new controller. Now at the time I used what was available, now better is available so the project involves and hopefully gets better 

[IanD]

6 hours ago, cuthound said:

 

Interesting.

 

I wonder what kind of boat they used? A 22"x13" prop is pretty big for the kind of narrowboat that would use a Beta 43 and 2800rpm is unacheivable on most canals.

Sorry, I didn't make it clear -- the 22" x 13" numbers (column D) were the only published accurate data I could find for absorbed prop power (64kW max at 2800rpm) vs. rpm, I then scaled these to the Beta 43 maximum output (43hp at 2800rpm) to get the numbers in column E, which were then used for calculations -- according to Beta this would probably need an 18" x 12" prop. Column I shows the maximum power vs. rpm read off from the Beta 43 data sheet, then column I shows the "spare" power available to drive a generator (and alternators if fitted).

Edited September 12, 2019 by IanD

[cuthound]

1 minute ago, IanD said:

Sorry, I didn't make it clear -- the 22" x 13" numbers (column D) were the only published data I could find for absorbed prop power (64kW max at 2800rpm) vs. rpm, I then scaled these to the Beta 43 maximum output (43hp at 2800rpm) to get the numbers in column E, which were then used for calculations -- according to Beta this would probably need an 18" x 12" prop.

 

Is there any imperical data to suppory your calculations for hydrid efficiency?

[IanD]

10 minutes ago, cuthound said:

 

Is there any imperical data to suppory your calculations for hydrid efficiency?

The references that were quoted earlier in the thread, IIRC this came out to about 20% total loss from power in to generator to power out of motor. If the losses are worse than this then the fuel saving will be smaller. With a bigger generator the fuel saving will be bigger. However it's clear that the "hybrids never save any fuel" statement can easily be wrong, which is the point I was making -- running a 43hp diesel at 4hp for cruising does give lousy efficiency, even worse when passing loads of moored boats nice and slowly (maybe 1hp), and idling in locks is obviously just pure wasted fuel (0hp). My guess is that by the time this (and solar panel power) is taken into account the real fuel saving with a hybrid will be something like 30%, maybe 40% with an optimum-sized generator -- which still doesn't pay back the installation cost, unless you were already going to have an electric-heavy boat.

Edited September 12, 2019 by IanD

[peterboat]

1 minute ago, IanD said:

The references that were quoted earlier in the thread, IIRC this came out to about 20% total loss from power in to generator to power out of motor. If the losses are worse than this then the fuel saving will be lower. However it's clear that the "hybrids never save any fuel" statement can easily be wrong, which is the point I was making -- running a 43hp diesel at 4hp for cruising does give lousy efficiency, and idling in locks is obviously just pure wasted fuel. My guess is that by the time this (and solar panel power) is taken into account the real fuel saving with a hybrid will be something like 30% -- which still doesn't pay back the installation cost, unless you were already going to have an electric-heavy boat.

I think a hybrid boat was sold recently which had low engine hours but high cruising hours, it was in one of the monthlys 

[IanD]

1 minute ago, peterboat said:

I think a hybrid boat was sold recently which had low engine hours but high cruising hours, it was in one of the monthlys 

Perfectly possible, by the time passing moored boats and locks are taken into account I suspect the average power over a day for a narrowboat is in the region of 2hp. With a 15kW (20hp) engine-driven generator (this is *huge* -- even the Integrel one is only 9kW) you'd only need to run the engine for about one hour a day to put this back, even allowing for losses. The hybridmarine system is about half this power (7.5kW/10hp) so would need to run for about 2 hours per day.

[WotEver]

3 hours ago, IanD said:

you'd only need to run the engine for about one hour a day to put this back, even allowing for losses

Only if you were using Lithium batteries. 

[peterboat]

9 minutes ago, WotEver said:

Only if you were using Lithium batteries. 

Or a lot of solar?

[IanD]

30 minutes ago, WotEver said:

Only if you were using Lithium batteries. 

Or lead-carbon which are supposedly perfectly happy not to be taken back to full charge every time.

 

Also note that if you had a 15kW generator and a 30kWh battery bank, it would only take about an extra 10 minutes of running to get the tail current right down...

Edited September 12, 2019 by IanD