New boat, conventional diesel or diesel hybrid?

[doris]

Looking at a possible new boat, and should the option arise, which should I specify, a conventional diesel/gearbox or a diesel electric hybrid????
Common sense says the hybrid but with the entire boating world being ridiculously conservative and resistant to modernisation, think of Freedom Yachts and carbon masts, a hybrid might be difficult to sell in the future.
A designed in battery would be part ballast, the generator can be put in the optimum position and an electric motor should be much more maintenance free than a gearbox. Would also have the likes of a Watt and Sea hydro generator as well.

Thoughts anyone???

 

[matt1]

Really want a Watt & Sea ;-) Will get one once I break free to do more adventurous passages

Spill the beans Doris...Production boat or one off? Designer?

 

[pvb]

There are efficiency losses involved in hybrid installations. There are also big complexity issues - these may be very important, depending on your intended destinations. You can get a conventional engine/gearbox repaired almost anywhere in the world.

 

[RupertW]

Looking at a possible new boat, and should the option arise, which should I specify, a conventional diesel/gearbox or a diesel electric hybrid????
Common sense says the hybrid but with the entire boating world being ridiculously conservative and resistant to modernisation, think of Freedom Yachts and carbon masts, a hybrid might be difficult to sell in the future.
A designed in battery would be part ballast, the generator can be put in the optimum position and an electric motor should be much more maintenance free than a gearbox. Would also have the likes of a Watt and Sea hydro generator as well.

Thoughts anyone???

I really don’t understand how a hybrid helps. Even if we forget about the extra weight of the electric drive and all the batteries which will cause higher energy use for a given speed, then it’s still an ICE driving the boat. And the diesel engine on a boat uses up most of its fuel on long trips doing a constant most economical speed, so converting that to electric power is just lossy.

I can see it making sense if you overnight in a marina every night and only do longer passages when the wind blows. But no point then in anything but electric drive and batteries.

 

[lustyd]

What's your intended usage of the boat? That's the big question, and anyone giving you answers before knowing it is probably defending their personal views rather than offering advice. You're right, an Oceanvolt will give you great regen from the propulsion, and the recent Uma video on Sanoma shows they can work well if you don't have a tight schedule or can be flexable on schedule.

 

[Frogmogman]

I can see the advantages of a hybrid installation on a catamaran; single generator, two electric motors (with vp screws) capable of hydrogeneration. After all, a lot of larger cats have two engines AND a genset. There’s a possibility of saving a load of weight, which is such a killer for multihulls.

On a monohull of a certain size (that can reliably sail at speeds of 7-9 kts) I can see the advantages of this sort of arrangement (from February’s YW). It provides a level of redundancy, and can be used for hydrogeneration. I can’t see the point for smaller boats that will more typically be sailing at 4-5 kts (Anderson 22 excepted, obviously).

It’s the sort of installation we have already discussed after Leo announced that it’s the sort of set-up he envisages for Tally Ho.

 

[doris]

The boat, 32-34 feet, will be used for channel/N European/Biscay cruising.
The hybrid route would remove the need for gas on board. Inverter, induction hob and electric oven.
Propulsion batteries are likely to be 24V or even 48V so there is still a requirement for domestic supply... however there are ways round this, solution still coming into focus, removing domestic batteries equals big weight saving.
Range should not be a problem at all given that a generator is much more efficient than your average thumper, although of course there are downstream inefficiencies to contend with before you get to the prop. Overall the diesel consumption would be less.
Still thinking.

 

[Adios]

I can see it making sense if you overnight in a marina every night and only do longer passages when the wind blows. But no point then in anything but electric drive and batteries.

That would suit a lot of people who only ever hop from one marina to the next. Stopping at an anchorage on the way won't use much more juice. But then even if there is a fair bit of motoring occasionally in a calm or up a river and the generator needs to come on after the charge has depleted still all the initial use, probably most of the use, will be from the recharges not the generator. It makes sense then. Extended remote cruising of course its less suitable as it will be all generated on the boat.

My worry would be the technology is moving fast so that it will be very outdated long before the boats end of life. As long as the batteries were changeable without having to strip out the interior I'd think it was a good bet still. I would love a quiet motor with no fumes and I'm sure many people would so selling shouldn't be a problem as long as the range and future proofing were ok.

 

[Tranona]

Suggest you look up Nigel Calder's reports on the hybrids he tried in his Malo - then fit a diesel plus a generator if your domestic electric requirements are greater than you can supply with your engine plus solar. His conclusion was that hybrid is not viable - even for a yacht his size and typical cruising usage.

Nothing ahs really changed in the meantime because of the inherent limitations of hybrid in terms of cost, size, weight and inefficiencies. The only thing that might change that is regeneration technology, and although that has improved recently it is still complex and does not yield the sufficient energy to be useful for propulsion.

I think Hybrid is a dead end, for automotive use and a non starter for leisure boat use.

 

[lustyd]

The boat, 32-34 feet, will be used for channel/N European/Biscay cruising.
The hybrid route would remove the need for gas on board. Inverter, induction hob and electric oven.
Propulsion batteries are likely to be 24V or even 48V so there is still a requirement for domestic supply... however there are ways round this, solution still coming into focus, removing domestic batteries equals big weight saving.
Range should not be a problem at all given that a generator is much more efficient than your average thumper, although of course there are downstream inefficiencies to contend with before you get to the prop. Overall the diesel consumption would be less.
Still thinking.

I think realistically hybrid is going to be as popular on boats as it is in cars so resale may be an issue once true electric takes off properly. Your requirements of electric cooking aren't realistic for pure electric right now from everything I've read so you'd either need to make compromises there, get a bigger boat for more solar/wind/battery, or keep the diesel in one form or another. I'd love to hear how you get on with hybrid though as I think it would be a good and practical system.
Aside from removing gas though, what's your motivation? Is it just lower/easier maintenance?

 

[dunedin]

The boat, 32-34 feet, will be used for channel/N European/Biscay cruising.
The hybrid route would remove the need for gas on board. Inverter, induction hob and electric oven.
Propulsion batteries are likely to be 24V or even 48V so there is still a requirement for domestic supply... however there are ways round this, solution still coming into focus, removing domestic batteries equals big weight saving.
Range should not be a problem at all given that a generator is much more efficient than your average thumper, although of course there are downstream inefficiencies to contend with before you get to the prop. Overall the diesel consumption would be less.
Still thinking.

Is the boat a new build ? And what is your budget ?

I think a hybrid drive system (electric drive and regeneration, plus diesel generator or fuel cell) would be an ideal propulsion system on new boat that is big enough and fast enough to
(a) sail at 7-8 knots regularly when dragging a regeneration prop
(b) carry the weight of the battery pack
(c) be in the price sector that a few extra £25k is rounding error.
Seem to be becoming slightly more popular options on high speed cruising cats, as a result.

Personally I can’t see it as a practical or especially economic option currently on a 32 foot cruising boat - unless
(1) cost no object ; and
(2) primarily day sail shortish distances between marinas with shore power.
There are plenty of examples of these now, but even without domestic electric systems, a £50k cost premium is not unusual.

If not on shore power, domestic systems are particularly challenging on electric power - you mention electric oven and induction hob, but presumably need to add water and cabin heating also, plus fridge. This would likely need a decent sized generator run frequently.
Read about Jimmy Cornell’s Elcano - 45 foot fast cat with all the latest tech, but even sailing at 8 knot averages the batteries went flat, partly due to the high domestic demands, to the extent that they had to abort their voyage.

As ever, good direction - but really need to do the maths on consumption, range, generation, weight and cost.

 

[Buck Turgidson]

32' and you want to cook on electric too!
I think you need to budget for a lot of diesel and a reliable gen set. Which kind of defeats the whole purpose. Plus at 32' where are you going to put it all?

 

[Tranona]

Agree with much of what dunedin and Frogmogman say. As an owner of a modern boat of just the size and type that you are thinking about, I have looked at this in some detail. Similar cruising expectations. The last of your benefits is the least sustainable. Diesel costs are essentially irrelevant. Most coastal cruisers do less than 100 hours a year which with the 30hp engine usually fitted equals about 175l or less than £200 a year. Tank capacity is normally 150l which gives you 80+hours motoring or 400 miles at 5 knots. Using Beta's estimations for their parallel hybrid 30hp, and a 200AH 48v (4*200ah 12v - imagine finding space for them in a 32' boat) you will get a range of 2-3 hours at 5 knots - that is less than 15 miles. Regeneration with a normal propulsion propeller is pitiful. To get 100W (2 amps @ 48v) you need to be sailing at over 5 knots - barely enough to run your 12v navigation gear.

Electric at the moment actually is more promising using the new regenerating pods. Nestaway boats have converted a Sadler 29 at a cost of around £10k (£3800 of which is the lithium battery pack), but still only get a range of less than 40 miles at 5 knots and minimal regeneration because of the low speed potential under sail.

Hybrid becomes more doable the larger the boat because there is space to fit larger serial hybrids and the larger battery banks required, but in reality offer no advantage over a diesel propulsion unit and a dedicated generator. However if your aim is to have an electric domestic system that is high usage such as air conditioning, electric sail controls etc then the new types of high output engine mounted alternators that use the surplus power of the propulsion unit (in much the same way as a calorifier uses waste heat) is worth considering as it eliminates the generator - but again for larger 45'+ boats. Nigel Calder has advocated (promoted) such things for the last couple of years.

For me the only step forward is to do away with the diesel altogether and key benchmarks for coastal sailing are 80 mile range at 5 knots an d a premium over a straight diesel installation of less than 15% of the total boat cost including battery pack. Long way off that for a 32' but getting closer for a 46' such as the Salona which has the space for the big bank, twin pods and a consistent sailing speed in the 6-8 knot range to give sufficient regeneration to at least cope with 12v systems demands and contribute towards propulsion usage.

 

[Rappey]

My worry would be the technology is moving fast so that it will be very outdated long before the boats end of life

I think similar. There are many different types of battery development going on, such as solid state and could require the sort of change as going from lead acid to lithium.
Can't see any saving over a normal diesel/drive especially when factoring in the higher initial cost for instalation.
If it's for environmental reasons then I sort of get that.

 

[Adios]

Agree with much of what dunedin and Frogmogman say. As an owner of a modern boat of just the size and type that you are thinking about, I have looked at this in some detail. Similar cruising expectations. The last of your benefits is the least sustainable. Diesel costs are essentially irrelevant. Most coastal cruisers do less than 100 hours a year which with the 30hp engine usually fitted equals about 175l or less than £200 a year. Tank capacity is normally 150l which gives you 80+hours motoring or 400 miles at 5 knots. Using Beta's estimations for their parallel hybrid 30hp, and a 200AH 48v (4*200ah 12v - imagine finding space for them in a 32' boat) you will get a range of 2-3 hours at 5 knots - that is less than 15 miles. Regeneration with a normal propulsion propeller is pitiful. To get 100W (2 amps @ 48v) you need to be sailing at over 5 knots - barely enough to run your 12v navigation gear.

Electric at the moment actually is more promising using the new regenerating pods. Nestaway boats have converted a Sadler 29 at a cost of around £10k (£3800 of which is the lithium battery pack), but still only get a range of less than 40 miles at 5 knots and minimal regeneration because of the low speed potential under sail.

Hybrid becomes more doable the larger the boat because there is space to fit larger serial hybrids and the larger battery banks required, but in reality offer no advantage over a diesel propulsion unit and a dedicated generator. However if your aim is to have an electric domestic system that is high usage such as air conditioning, electric sail controls etc then the new types of high output engine mounted alternators that use the surplus power of the propulsion unit (in much the same way as a calorifier uses waste heat) is worth considering as it eliminates the generator - but again for larger 45'+ boats. Nigel Calder has advocated (promoted) such things for the last couple of years.

For me the only step forward is to do away with the diesel altogether and key benchmarks for coastal sailing are 80 mile range at 5 knots an d a premium over a straight diesel installation of less than 15% of the total boat cost including battery pack. Long way off that for a 32' but getting closer for a 46' such as the Salona which has the space for the big bank, twin pods and a consistent sailing speed in the 6-8 knot range to give sufficient regeneration to at least cope with 12v systems demands and contribute towards propulsion usage.

Sounds like boats motors are heading back to providing just auxiliary power. Could put the emphasis/challenge back into sailing.

 

[Tranona]

Sounds like boats motors are heading back to providing just auxiliary power. Could put the emphasis/challenge back into sailing.

Yes, if you you look at this you will see that is
one of the big selling points by the US dealer.youtube.com/watch?v=jpAnGJpcnQU

 

[Laminar Flow]

Considering that a sailboat is already the penultimate hybrid, I think this idea is pretty much a non-starter.

I sail and cruise and also live in areas where tidal currents out strip the capability of most electric drives.
Hybrid as a motorized propulsion system effectively means a significant increase in systems, their maintenance and the overall weight a boat has to carry. In this regard, I suspect that a vessel will have to be even significantly larger than 45' to absorb the inevitable and significant sacrifice in performance to be expected.

As the average relative speed for a sailing vessel is 0.9, a vessel capable of averaging 7-8kts would need a DWL of about 70'.

 

[skipmac]

Downsides to a hybrid.

- More expensive to buy
- More expensive to repair
- More complex so more to break
- If you break down 100 miles east of nowhere you will have a problem A. getting parts B. finding someone that knows how to work on it.

If your boating plans are exclusively close to home or close to major boating centers where you can get service and you are ready for a big repair bill if something blows up then why not give it a go.

 

[Daydream believer]

I already have hybrid power. I either motor it or sail it. Good enough for me

 

[lustyd]

I already have hybrid power. I either motor it or sail it. Good enough for me

You don't motorsail?