Electric Boats

[John100156]

Electric boats do not currently stack up.

Not currently, for any sizable boat I agree but I expect as new technologies develop, particularly given significant investments in chemical energy conversion to generate electricity (batteries) and other similar sources (fuel cells) I think EBs may stack up sooner than we might think! I applaud those that are dipping their toes in. Interesting debate but one for the future perhaps.

 

[BruceK]

For leisure motor boating to survive we must reform and reconsider what is "necessary". ....... For more sociable cruising, perhaps we need to consider reducing speed and enjoying our time on the water.

Why does that give me the mental image of Greta Thunberg belting out the lyrics to Slow Down for What? Not good enough I'm afraid.

 

[Martxer]

I am sure these were not possible a few years ago Lift Foils | LIFT3 | 4’2 Pro eFoil
Someone will be clever enough to make it happen at some point

 

[gyislander]

An interesting post and discussion but come back David and respond to the questions raised in the post you started. Nothing worse than a disappearing firestarter.

 

[TNLI]

I would like to respond to some letters in the Dec MBY magazine.

As highlighted by Mike King-Harman there is an environmental impact from manufacturing batteries and this needs to be reduced. Within the next few years we will start to see much cleaner battery technology, which is currently in development. The other way to reduce this impact is by developing much more energy efficient hulls, which is the approach we are taking with our new range of electric boats. Our 10m boat will only carry 50% of the batteries of some more conventional alternatives, saving 800kg, significant cost and environmental impact, while still delivering a range of up to 200 miles.

The other issue is speed. Roland Watkins says he is yet to convinced that electric boats will offer the "necessary speed and range". There are now plenty of high-speed small electric boats on the market if that's what is required. But we should question the need or even desirability for high speeds. By reducing speed we can achieve a dramatic reduction in energy consumption and comfort and then enjoy the journey, but not with a planing hull. This led us to develop a very novel wave piercing hull that will cruise at twice conventional displacement speeds, up to 15kts in our 10m boat and 20kts in a 12m boat, economically with zero-emissions.

For leisure motor boating to survive we must reform and reconsider what is "necessary". If you wishDa to blast around at high speed in sheltered waters then a foiling boat such as Candela is a great option. For more sociable cruising, perhaps we need to consider reducing speed and enjoying our time on the water.

David Kendall

What we need is lighter hulls and alas that means Carbon fibre panels for the go fast boy or girl racers. For the more adventurous the existing full displacement hulls built of anything except steel are perfectly OK, BUT in both cases the power to weight ratio of the batteries does matter. Alas nothing beats Lithium Iron, with NiCad's second.
Afghanistan has by far the biggest deposits of Lithium ore in the world, and none of them have been touched. The best ore fields are down South as they are mixed with ultra fine Gold deposits, so far more profitable than the deposits in central Afghanistan. China got the rights to the biblical Copper ore deposits in the North East, but the rights to the Lithium ore fields are still up for grabs. If we, as in the rich Western countries can get the Li ore fields it will make a huge difference to the cost of Li batteries.
The US, Canada and Australia have plenty of nickel and Cadmium, but no cheap Li ore fields.

 

[Elessar]

What we need is lighter hulls and alas that means Carbon fibre panels for the go fast boy or girl racers. For the more adventurous the existing full displacement hulls built of anything except steel are perfectly OK, BUT in both cases the power to weight ratio of the batteries does matter. Alas nothing beats Lithium Iron, with NiCad's second.
Afghanistan has by far the biggest deposits of Lithium ore in the world, and none of them have been touched. The best ore fields are down South as they are mixed with ultra fine Gold deposits, so far more profitable than the deposits in central Afghanistan. China got the rights to the biblical Copper ore deposits in the North East, but the rights to the Lithium ore fields are still up for grabs. If we, as in the rich Western countries can get the Li ore fields it will make a huge difference to the cost of Li batteries.
The US, Canada and Australia have plenty of nickel and Cadmium, but no cheap Li ore fields.

lighter hulls irrelevant. Stabs, cooling and heating at rest means batteries no use for a cruising boat. So where the metal comes from also irrelevant.

 

[vas]

should ask Bart to remind us how big the battery bank on BA is that can run his el. stabs for an evening. No aircon afaik running off batteries.
Unless stored energy density improves substantially (as in massively) I think we are slightly stuck where we are, or we should all stick a mast and flappy things!

 

[dunedin]

should ask Bart to remind us how big the battery bank on BA is that can run his el. stabs for an evening. No aircon afaik running off batteries.
Unless stored energy density improves substantially (as in massively) I think we are slightly stuck where we are, or we should all stick a mast and flappy things!

I think the point perhaps is that if we want to tackle climate change, we may need to do things differently. That might mean:
- using smaller boats - who needs a boat more than 40 foot or so?
- not travelling at such high speeds
- not running air conditioning but having natural ventilation
- not running stabilisers all night
Perhaps displacement catamaran might help with some of these

Nobody pretends that doing exactly what we do today would work with a switch to electric. But we can enjoy boating in more environmentally way by changing things, and being more modest in our aspirations. And we might even find it is as much if not more pleasant

 

[Elessar]

I think the point perhaps is that if we want to tackle climate change, we may need to do things differently. That might mean:
- using smaller boats - who needs a boat more than 40 foot or so?
- not travelling at such high speeds
- not running air conditioning but having natural ventilation
- not running stabilisers all night
Perhaps displacement catamaran might help with some of these

Nobody pretends that doing exactly what we do today would work with a switch to electric. But we can enjoy boating in more environmentally way by changing things, and being more modest in our aspirations. And we might even find it is as much if not more pleasant

Who needs a boat at all?
Preach somewhere else.

 

[Mistroma]

Not currently, for any sizable boat I agree but I expect as new technologies develop, particularly given significant investments in chemical energy conversion to generate electricity (batteries) and other similar sources (fuel cells) I think EBs may stack up sooner than we might think! I applaud those that are dipping their toes in. Interesting debate but one for the future perhaps.

Yes, it probably needs to be chemical conversion and therefore a fuel rather than a battery. Diesel releases a lot of energy per kg or litre. Batteries are not in the same ballpark at present and unlikely in the foreseeable future, if at all.

I won't quote MJ/L or MJ/kg, engine efficiencies etc. and just take some real life figures instead. Perhaps someone would like to check my very rough calculation to point out any glaring errors.

A 13.5kWh Tesla Powerwall weighs 125kg. and that's about the same weight of approx. 147 litres of diesel.

My Yanmar engine will take about 50 hours to use that amount of diesel if run at my usual cruising speed with about 12 hp at the prop. (equivalent to 9kW)

If these figures are correct:

125kg battery will give ~1.5 hours cruising​

125kg diesel will give ~33 hours cruising​

The battery would need to improve by a factor of 22 to match diesel. Other battery technologies aren't massively better than ones used by Tesla, don't expect a ten-fold improvement by switching brand.

You are still carrying around a 125kg battery when out of power and all diesel consumed. I realise that a diesel engine is going to be heavier than an electric motor and that offsets the weight to some extent.

Alternative fuels have problems but do seem more promising than a rapid improvement in battery technology on the scale required. Most likely candidates are generally based on hydrogen in one form or another (hydrogen, ammonia, hydrazine, lithium borohydride, etc.). All of these require development to overcome inherent problems. I know there are other technologies but at least the ones I mentioned just use oxygen from the air rather than carrying it around as part of the fuel.

 

[John100156]

...Even your efficient aircon doesn’t stack. It might one day. But it doesn’t now....

There are other forms of cooling that could be considered to generate chilled water on a boat, and we could all probably better manage cooling (which I don't), without suffering too much, not just electric powered reverse cycle heat pumps of course; perhaps Lithium Bromide absorption chillers, that use waste heat to drive a generator instead of a compressor. So how could we generate enough heat? Easy when motors are running but at anchor? PV to resistive heating elements perhaps, also is there by chance any sun around to heat water when the cooling is needed? Buggered at night, unless sea temps are cooler....

Of course, I am just playing around with all this so as to stimulate and encourage debate (sorry OP). We would need to consider the energy balance(s) carefully (not viable yet) and the cost of developing systems; much cheaper to continue to use diesel and heat pumps, no current major financial incentive WHILST we have the former energy source available to leisure boats, ignoring the obvious...!

I too think H2 and other gasses will play a major roll in our future, I have said this for many years, after all, it is the most abundant gas in the universe and we sail our boats on a fair amount of it, cost of generation an issue? Getting cheaper? For those that may be interested, I just designed and completed the services design to the VoC labs shown below for ICL at the Hammersmith, I used an H2 generator rather than cylinders (reduced fire risk and gas detection an alarms required), I piped H2 and other gasses into various labs, note the glass vessel of H2O in close proximity to the Peak stack, the latter also included a synthetic air generator:



I am glad that people are seeking now to develop new technologies and EB's which should be encouraged IMHO I share many of the concerns raised as I have said, but I believe like most things, solutions can and will in time be found!

 

[Bigplumbs]

That sour faced Gretta like Extinction rebellion and those other idiots do far more to turn people away from their cause than for it

Sitting on the M25 the other day waiting for the Police to move the silly sods made us totally against the whole thing. If we are expected to save the planet for the spawn of those idiots then I am out

 

[vas]

Yes, it probably needs to be chemical conversion and therefore a fuel rather than a battery. Diesel releases a lot of energy per kg or litre. Batteries are not in the same ballpark at present and unlikely in the foreseeable future, if at all.

I won't quote MJ/L or MJ/kg, engine efficiencies etc. and just take some real life figures instead. Perhaps someone would like to check my very rough calculation to point out any glaring errors.

A 13.5kWh Tesla Powerwall weighs 125kg. and that's about the same weight of approx. 147 litres of diesel.

My Yanmar engine will take about 50 hours to use that amount of diesel if run at my usual cruising speed with about 12 hp at the prop. (equivalent to 9kW)

If these figures are correct:

125kg battery will give ~1.5 hours cruising​

125kg diesel will give ~33 hours cruising​

The battery would need to improve by a factor of 22 to match diesel. Other battery technologies aren't massively better than ones used by Tesla, don't expect a ten-fold improvement by switching brand.

You are still carrying around a 125kg battery when out of power and all diesel consumed. I realise that a diesel engine is going to be heavier than an electric motor and that offsets the weight to some extent.

Alternative fuels have problems but do seem more promising than a rapid improvement in battery technology on the scale required. Most likely candidates are generally based on hydrogen in one form or another (hydrogen, ammonia, hydrazine, lithium borohydride, etc.). All of these require development to overcome inherent problems. I know there are other technologies but at least the ones I mentioned just use oxygen from the air rather than carrying it around as part of the fuel.

calcs look ok and I agree what all that.
just for the record I'm building a circa 8kWh LifePO4 battery for my mobo, it's going to be 50odd kg (well 45 for the cells, and I give another 5kg for a case and bms)
so, you'd gain 25kg going my route (and a bit of dosh as whole exercise will be at circa 1400euro!) ?
if it goes well (should do!) I'm thinking of converting my jetrib to electric in a year or two (and have it in standby as a range extender for the house batteries as well ?

V.

 

[vas]

I think the point perhaps is that if we want to tackle climate change, we may need to do things differently. That might mean:
- using smaller boats - who needs a boat more than 40 foot or so?
- not travelling at such high speeds
- not running air conditioning but having natural ventilation
- not running stabilisers all night
Perhaps displacement catamaran might help with some of these

Nobody pretends that doing exactly what we do today would work with a switch to electric. But we can enjoy boating in more environmentally way by changing things, and being more modest in our aspirations. And we might even find it is as much if not more pleasant

tbh, whilst I don't disagree with what you say (although I think your first suggestion is plain silly, it's like saying why have more than 2kids, and who needs a seven seater car, and why have more than a 3bed house!)
EVS started picking up once they got good enough to use as your normal ICE car. OK, there's a price premium and crappy charging services around, so still mostly a city/small range vehicle. and it took some years, and dont forget a car can and in many cases is a means to doing your normal daytime job an essential apparatus...

Now, the boats we are talking about are 99% NOT essential (I hope you don't expect us to believe that fishing fleet is going to get rid of diesel anytime soon), so somehow you expect us to alter a leisure activity to the extent that it's not leisure anymore! Why and who you think is going to follow? and at what premium?
Get a sailing cat, fit 2-3kw of solar, get 300kg of lithium batteries (say 50kWh worth of energy storage) two 30odd kW el. motors and go your merry way, many wont!

 

[Mexican]

I think that not enough is being said about hydrogen fuelled ic engines - there are currently trials being conducted by multiple companies with JCB already producing engines to power diggers and heavy machines - no emissions, fill time of tanks the same as diesel and not hours, with possibly fewer environmental concerns in manufacture and with possible performance closer to what we have now...........battery lobby winning?

 

[vas]

I think that not enough is being said about hydrogen fuelled ic engines - there are currently trials being conducted by multiple companies with JCB already producing engines to power diggers and heavy machines - no emissions, fill time of tanks the same as diesel and not hours, with possibly fewer environmental concerns in manufacture and with possible performance closer to what we have now...........battery lobby winning?

safety of storing hydrogen I thought was the greatest setback. Any new developments there?

 

[Mexican]

Not sure of any safety developments vas - but with time I guess safety 'gets sorted'. I can recall my dad who lived on a boat in Cannes in the 50's saying he would never have gas on a boat or a petrol powered boat due to the preponderance of explosions/deaths due these-due to various reasons!

I just think that this may be a better option for those wishing to maintain what they have in terms of performance and ease of 'refuelling' and stay boating for any length of time and not worry about charging our batteries every hour or so!

 

[Rwc13]

”tbh, whilst I don't disagree with what you say (although I think your first suggestion is plain silly, it's like saying why have more than 2kids, and who needs a seven seater car, and why have more than a 3bed house!)”

But all actually not silly questions in a world that surely must start to recognise sooner of later that the rate of population growth has been and is unsustainable, and where pure show off consumerism (where size/price/speed etc is not really driven by need) is likely to become very much less socially acceptable.

Whether we like it or not, change is coming for boats as the technology evolves to get closer to meeting the demands of customers - which it will - as with EVs. That change will either be driven by the consumer or by regulation eventually. So I think we should be encouraging rather than disparaging of those investing in new technology as they are most likely to be responsible for us being able to continue this leisure activity into the long term future.

 

[henryf]

If you’re happy to go slowly there is something called a sailing yacht. You can also go slowly in your current boat and use minimal amounts of fuel. With optimal tides in the Solent our 50ft flybridge can manage 9 or even 10 knots for around 15 litres of fuel per hour. Factor in the carbon footprint of building and scrapping huge batteries possibly 2 or 3 times in the boat’s lifetime and I wonder how much of a saving you’re really going to make in the real world.

We also have the ability to go 30 knots when the need arises or we are dividing usage between 12 charter guests.

Talk of doing away with air-con and improving air flow is fanciful in places like Thailand. Similarly try boating without heating in the UK! You might manage an overnight stop on batteries but the whole point of slower cruising is that it takes days and weeks not hours. You need to cope with 2 or 3 weeks on board.

Do all electric cruising boats have a place? No. Does hybrid technology have a place? Possibly but you need to make sure you aren’t just jumping on a bandwagon for no material gain.

I think we are a long way off in terms of technology at the moment. I would be looking at like someone like JCB who are essentially dealing with the same issues the marine industry faces. They seem to favour hydrogen internal combustion engines. That would be where my money went in the short to medium term.

 

[henryf]

If you’re happy to go slowly there is something called a sailing yacht. You can also go slowly in your current boat and use minimal amounts of fuel. With optimal tides in the Solent our 50ft flybridge can manage 9 or even 10 knots for around 15 litres of fuel per hour. Factor in the carbon footprint of building and scrapping huge batteries possibly 2 or 3 times in the boat’s lifetime and I wonder how much of a saving you’re really going to make in the real world.

We also have the ability to go 30 knots when the need arises or we are dividing usage between 12 charter guests.

Talk of doing away with air-con and improving air flow is fanciful in places like Thailand. Similarly try boating without heating in the UK! You might manage an overnight stop on batteries but the whole point of slower cruising is that it takes days and weeks not hours. You need to cope with 2 or 3 weeks on board.

Do all electric cruising boats have a place? No. Does hybrid technology have a place? Possibly but you need to make sure you aren’t just jumping on a bandwagon for no material gain.

I think we are a long way off in terms of technology at the moment. I would be looking at like someone like JCB who are essentially dealing with the same issues the marine industry faces. They seem to favour hydrogen internal combustion engines. That would be where my money went in the short to medium term.

An interesting article about hybrid Hydrogen / diesel technology as a retrospective conversion on diesel engines.

How Hydrogen Is Making Diesel Better