Why the slow progress on hybrid engine systems?

[ex-Gladys]

I would expect that a lightweight petrol engined package would pose a considerable downside from the fuel consumption point of view.
Apart from the inherently greater consumption compared with diesel, there are also the energy conversion (and storage?) inefficiencies.

Have you seen the consumption figures for the 1litre turbo petrol engines being used in cars such as the Ford Focus (120 BHP, 65MPG)? Wish my car was as frugal

 

[Tranona]

Lynch motors, digital control and lithium-ion batteries have not been around for a hundred years. He seems very happy with the solution he has, so I shan't spoil it by telling him that he can't be.

But it is still an electric motor driving a propeller with energy coming from an external (to the boat) power source. The only difference with the newer type of motor, better battery and digital controls is in increasing the range. However it is still an inadequate substitute for a diesel auxiliary.

 

[Tranona]

I would expect that a lightweight petrol engined package would pose a considerable downside from the fuel consumption point of view.
Apart from the inherently greater consumption compared with diesel, there are also the energy conversion (and storage?) inefficiencies.
Granted, annual fuel cost for yachts isn't usually a significant consideration, but endurance is. My 60 l. diesel tank gives ~40 hours running.
This would be much less for petrol electric,( maybe a factor of 2). I suppose I could shoehorn in a bigger tank, but bang goes my carbon footprint, and my light weight!
Incidentally, the Calmac Bute ferries have a central motor generator with an electric drive at each corner, no shafts.

You would not need a high powered engine to charge the batteries if the electric motor was the only means of propulsion. No reason why fuel consumption would be any higher as the power requirement (and therefore energy) would be the same.

The ferry example is a good illustration of how different requirements lead to different solutions. One of the problems with conventional power is that the engine (usually) has to be in line with the propeller which is very limiting if you you want a wide flat load area covering the middle of the boat. So engines at the side are common on ferries so it makes sense to have drive pods which have the advantage of being independently controllable. You find similar systems on cruise ships where the main power requirement is for electricity to run the ship so a generator is required anyway. Propulsion power is through pods which also aids manoeuvrability making the ships largely independent of tugs for berthing.

 

[lw395]

Have you seen the consumption figures for the 1litre turbo petrol engines being used in cars such as the Ford Focus (120 BHP, 65MPG)? Wish my car was as frugal

Which shows that hybrid is not really about economy in cars.
It's about air quality in cities, getting rid of excessive idling and low load running.
Which is a good thing.
But it probably saves no resources or money.

What is the imperative to have a hybrid system on a yacht?
I don't see one. At least for any users I am familiar with.
I can see more takers for a pure electric, charge at the marina system, for racing dayboats needing just a few minutes power among the pontoons.

Maybe the odd person might buy a yacht with the intent of doing virtually zero motoring, but need a generator and batteries for all the electrics we lumber ourselves with.
Then you might add a small motor to use in flat calms and 'parking'.
More of a fore and aft version of a bow thruster than a propulsion engine perhaps?

But TBH, a conventional motor is cheap in yacht terms, if you want to be greener just don't use it so much!

 

[westernman]

You would not need a high powered engine to charge the batteries if the electric motor was the only means of propulsion. No reason why fuel consumption would be any higher as the power requirement (and therefore energy) would be the same.

The ferry example is a good illustration of how different requirements lead to different solutions. One of the problems with conventional power is that the engine (usually) has to be in line with the propeller which is very limiting if you you want a wide flat load area covering the middle of the boat. So engines at the side are common on ferries so it makes sense to have drive pods which have the advantage of being independently controllable. You find similar systems on cruise ships where the main power requirement is for electricity to run the ship so a generator is required anyway. Propulsion power is through pods which also aids manoeuvrability making the ships largely independent of tugs for berthing.

Yes, those are good examples of diesel-electric propulsion.

But they are not hybrids in the sense that most people understand today in the sense of a Toyota Prius (no intermediate storage of energy in a battery).

Also, another requirement for cruise liners is that they need to be able to cover a range of speeds to ensure they arrive at the right time. People will be miffed if their cruise ends up being a few hours short because the ship steamed too fast. This is easy to do reasonably efficiently with diesel-electric by changing the number of generators they have on line at any time. Efficiency does suffer a bit with the conversion losses - but those generators are all running close to maximum efficiency.

Efficiency is why all the big container ships today almost all use a single big diesel engine and are designed to steam at a certain constant speed.

Batteries are only of interest if you can fill them up from another source. However, once away from the dock those other sources are very limited in power compared to a few litres of diesel. Also batteries are expensive and store very little energy compared to a few litres of diesel.

And interesting exercise is to calculate the cost and weight of batteries required to replace a typical car's tank of 70 litres of diesel. (You could buy a new Mercedes for the cost....)

 

[earlybird]

Since it's raining, and I've nothing better to do!
Diesel is ~10kWHr /litre so, for 70 litres x 25% efficiency (say) = 170kWHr:-
34 Mastervolt batteries, that I mentioned earlier, would weigh 2 Tonnes and cost ~£150K although I'd expect quantity discount to bring this down to ~£40K. so an E Class is within budget .
Incidentally, 170kWHr would cost ~£2.50 on my domestic tariff cf. £70 for diesel, of which £50 goes to George.

 

[westernman]

Since it's raining, and I've nothing better to do!
Diesel is ~10kWHr /litre so, for 70 litres x 25% efficiency (say) = 170kWHr:-
34 Mastervolt batteries, that I mentioned earlier, would weigh 2 Tonnes and cost ~£150K although I'd expect quantity discount to bring this down to ~£40K. so an E Class is within budget .
Incidentally, 170kWHr would cost ~£2.50 on my domestic tariff cf. £70 for diesel, of which £50 goes to George.

In a boat you get better than 35% efficiency from a diesel engine when reasonably loaded.

 

[mobeydick]

Google 'Lagoon 420 Hybrid' and also see

http://www.cruisersforum.com/forums/f139/lagoon-420-owners-and-fans-5250.html

For the full story of a major manufacturer trying to do this. I don't think many if the reasons for the failure have changed.

MD

 

[Twister_Ken]

Of course, you can always have photovoltaic panels on the sails (and elsewhere).

(boat, Arcona 380Z)

 

[prv]

Thinking a bit more about the problem, perhaps my negativity is because almost all the hybrid solutions are based on using existing diesel engines to both generate electricity and propulsion usually with the option of electric propulsion. This results in them being bulky heavy and expensive.

Going back to JD's expectation of a dual power 5kw power plant with the option of propulsion from either source, maybe if the dual power bit is dropped and electric only propulsion used as a starting point a different and probably more viable solution may be possible.

Haven't done even finger-in-the-air numbers, but would a fuel cell running on methanol work here? Assuming the price of them comes down a bit in the future and perhaps a modest increase in efficiency?

Pete

 

[JumbleDuck]

Economic arguments must have some impact.

Some, but not much. Nobody needs a yacht.

I really doubt that a hybrid electric/diesel solution will be economically attractive for yachts in the foreseeable future.

Nothing on a yacht is economically attractive.

[quote[I don't think that I was comparing my requirements to those of others. Simply making generalisations about cost, complexity and the size of the likely market.[/quote]

Indeed you were not.

You may well be happy to spend a lot of money on a system with more limitations than a standard diesel and I'm certain you won't be completely alone. My point is that you won't be in the majority (by a long way) and most boat builders aim to supply the mass market.

Hmm. What I am hoping for (a 5kW diesel with 5kWh of electric available for £5k) would have significant advantages over a diesel. Need a ten minute run to get out the marina? Electric, available instantly and silently. Need a ten hour run up the Irish Sea? Diesel, nice and efficient. Need a quick blast of double power to get past the Mull of Galloway or get back to an MOB? Use both. Why carry twice as much diesel engine as you need around with you, irritating it by running it lightly loaded 90% of the time?

No, I probably won't be in the majority, but that doesn't mean that the whole notion is pointless.

Tosh and piffle. Economics are king - that's why production builders account for 90% of sales and relentlessly drive down costs so that buyers get more for their money or spend less, it's all about the money, that's why there's no real innovation.

So why do people buy new Bavarias instead of second hand Westerlies at perhaps a quarter of the price per foot?

But it is still an electric motor driving a propeller with energy coming from an external (to the boat) power source. The only difference with the newer type of motor, better battery and digital controls is in increasing the range. However it is still an inadequate substitute for a diesel auxiliary.

You might as well say that laminate sails are basically the same technology which the Great Britain made outdated in 1845. If you read my posts, you will see that I am not suggesting that electric power will replace diesel auxiliaries - simply that the use of electric power for short distances is not a chimera.

Yes, those are good examples of diesel-electric propulsion.

But they are not hybrids in the sense that most people understand today in the sense of a Toyota Prius (no intermediate storage of energy in a battery).

Guess what this is.

And interesting exercise is to calculate the cost and weight of batteries required to replace a typical car's tank of 70 litres of diesel. (You could buy a new Mercedes for the cost....)

Indeed. That's why I don't see electric propulsion as a viable long-range alternative to internal combustion. Neither would it work on a boat as it does on cars, where regenerative braking is the USP. The point in marine use is to be able to use a relatively small diesel engine running at maximum efficiency, with surplus power stored in batteries ready to boost the engine's output when required.

 

[NormanS]

JD, you show a PIC of the Hallaig, which does a very short run across to Raasay from Sconser. At Sconser it plugs in to mains power. Most of us require our auxiliaries to take us a lot further, and to places where shorepower is not available. Seems hardly relevant. Indeed a rubber band could achieve as much.

 

[Tranona]

You might as well say that laminate sails are basically the same technology which the Great Britain made outdated in 1845. If you read my posts, you will see that I am not suggesting that electric power will replace diesel auxiliaries - simply that the use of electric power for short distances is not a chimera.

Your sail example just illustrates the point. It is still wind power, just the material used has changed. Boats have been powered by electricity for over 100 years. All your mate's boat does is do it for a bit longer. The major drawback of still needing to charge the batteries from a shore supply continues meaning severe limitations to what you can do with the boat compared with having an independent source of power (subject of course to on board fuel capacity)

So does not prove that electricity is viable, only that it is possible as it has been for a long time.

 

[JumbleDuck]

JD, you show a PIC of the Hallaig, which does a very short run across to Raasay from Sconser. At Sconser it plugs in to mains power.

She's actually a diesel-electric hybrid. They have launched two more since: the Lochinvar and the Catriona. One good use of hybrids is for the service pattern you outline: smaller diesels running continuously with the battery/motor system meeting a fluctuating requirement.

Some years ago I sketched out a glider winch design which worked in a similar way. They need something like 200hp for one minute out of every five, which is generally done with a stonking great diesel. My idea was to use a 40hp diesel and a bank of batteries: the diesel would run continuously, charging the batteries 4/5 of the time and then joining with them to launch.

It wasn't viable then because of the weight and cost of the batteries, but I think it's getting more practicable. Another use is for all-electric launching. 200hp is a hell of an electric supply, but 40hp is 30kW which is fine with a standard 62A 415V 3-phase supply, so all you need is a power point at each winch position and a winch with battery charger, battery bank and big electric motor. That was never a runner with lead-acid because the recharging has to be done very fast, but Li-ion would be fine.

 

[JumbleDuck]

Your sail example just illustrates the point. It is still wind power, just the material used has changed. Boats have been powered by electricity for over 100 years. All your mate's boat does is do it for a bit longer. The major drawback of still needing to charge the batteries from a shore supply continues meaning severe limitations to what you can do with the boat compared with having an independent source of power (subject of course to on board fuel capacity)

If only there was a name for a system which combined diesel and electric power in some way, eh?

 

[Allan]

Whilst recovering from pneumonia a couple of years ago I started designing my 'lottery boat'. Most of it was simple as I love my existing boat, so I started to concentrate on the drive system. I stress it was for ME! I'm the first to put up my sails and the last to drop them. I never have to rush back and if the wind drops I normally put the kettle on or anchor and open the wine. So a very specialised system.
I planned two electric motors, some of the recently developed ones I have read about, possibly the fixed magnet ones mentioned earlier. With some relatively simple engineering the props could also be used to drive generators when sailing. The motors would take power from the best value batteries of the time. Value being defined by weight, efficiency and life expectancy. Having a large weight that can be mounted around the boat I see as an advantage. Apart from the water powered generation, there would be as many PV panels as practical. There would also be a small diesel generator. I spoke to a friend of mine who spent most of his working life with generators, he said they were becoming much more efficient. He also said some use the same idea as in formula one, ie. using power wasted at a turbo charger to boost the electrical output.
The key would be the control system. It would need to monitor the batteries and know what you intend to do.
All I need to do now is start buying lottery tickets!
Allan

 

[PabloPicasso]

Why have hybrid engines been so slow to come to the sailing market, while they are being adapted with much alacrity by the road vehicle market? Over the past decade or so, a number of systems have come and gone, often from small companies which have not had the resources to overcome teething difficulties. None of the large engine manufacturers (except Nanni) have made any serious attempt to perfect the technology, and even Nanni seem to not be trying to hard.

Do you really want a whole other level of unfixable complexity to rely on at sea? The batteries will die just as you are my the rocky ledge by the harbour entrance etc. Water and electrics are a poor mix at the best of times, why add engine complexity in this area?
Is there some compelling technical reason why this technology is so difficult to make work on the sailing boat market? The economies of scale of the vehicle market are clearly not the same in the boat market, but nevertheless I would have thought there would be more adaption by now.

I would really be interested in fitting a system if it could provide 220v ac while in diesel mode, provide regenerative power when sailing at hull-speed (but importantly have the possibility to switch back to low drag when in light winds), and be from a major manufacturer.