Electric sportcruiser

GARYSJENKINS

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I have replies to my question of diesel or petrol, thanks
One thing that does not seem to be on the horizon are electric options. Unlike the car industry having a fixed date to stop supply of new petrol vehicles does the marine industry have a target. What, if any, engines are on sale or soon to market. Retrofitting deisel with electric coming along? Presume straight swap with outboards will be the first to arrive.
 

Freebee

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To use electric power means batteries and to have meaningful range the battery bank will be large and weigh a lot, weight carried on wheels is fairly easy to cope with ,big weight in a floaty thing is not so easy to cope with. Until battery technology makes batteries more powerful and light in weight its not going to be that viable.
 

BruceK

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what he said. Energy density gram for gram batteries fall far short of fossil fuels. I really doubt batteries will ever be more than a niche market in the boating world. A cleaner fuel type, LPG or similar far more likely.
 

ontheplane

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Yep, electric boats impractical until battery energy density massively increases, and even then, recharging totally impractical.

Can be done at low displacement speed, but once you move to planing speeds, it can't work yet - not sure it ever will.
 

oldgit

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Bit late ?
somebody better tell ths bloke...10 years ago
More electric speedboats under development than you can shake a stick at on Youtube



.......and those electric aircraft will never get orf the ground or course ?

How much fuel does the boat carry ? what do the fuel tanks/engine(s) and gearbox(es) weigh, no need for engine starter or domestic batteries either .
 
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Bouba

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While the option of electric/battery exists, it is eye wateringly expensive.
The future has to eventually include electric trucks. That is when we will get a cross over to boats and acceptable storage/cost.
 

ontheplane

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But charging will always be an issue.

So assuming a car does 40mpg (mid size diesel) and a boat does 2mpg (mid size diesel boat.

My electric car does 280m on a charge, so with the same size battery a boat might do 14m......

Scale up the battery to give a 250 mile range with a 20% margin (so a 300 mile range) it will need a 1340kwh battery - a 67kwh battery for my car is about £18,000. So the battery for the boat would be about £360,000........

A 1340kwh battery even on the fastest charger currently available in normal use in the uk is 150kw so it would take 7hrs to charge from 20-80% and then another 7 hours to charge the rest of the way - and you shouldn’t fast charge for more than about an hour.......

On a normal 7kw car charger it would take 191 hours......

If on a typical weekend half the boats in the marina went out and wanted to charge on a rapid charge overnight for the next day, let’s say 500 boats at 150kw, the marina would need a 75 Megawatt supply - so it would need something about 1/4 the power of Hinckley B hooked up directly to it!!!

Totally and utterly impractical - never mind the kind of cabling needed to supply that kind of power.

It would work as long as only 5 people a day used their boat, and then left it a week to charge......
 

ontheplane

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That MARIAN above, whilst very pretty, has a 150kw motor (about 170hp)) and a 175kwh battery pack, so at 2/3 power it will run about 90min.

But running off a standard 16a shorepower, will take 45hrs to recharge...... it will be cheap, costing about £20-30 to recharge depending on tariff - but is 90 minutes running per weekend enough?

If there were shoreside rechargers at say 350kw (the very very fastest you can currently get) it would do 20-80% in about 20-30min, so not so bad, but hard to set them up mid-lake?
 

[2068]

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Most diesel cruisers have something like a 8-10 hour endurance.
Electric boat batteries are x6 off that at the moment.
That might change in the future, but not anytime soon.

Hybrid powertrains are probably the way forward for cruising boats in the medium term.
 
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The energy density of batteries is so low that there is no practical solution for electric engines in boats other than little tenders, river day boats at displacement speeds and perhaps some small foiling day boats.

Even hybrid things like the Greenline 40 will do about 4 knots on electric for about 3 hours so a range of 12NM going at a crawl. So essentially useless for anything other than niche uses like a river boat.

Just for fun let's do some quick math on the 150hp electric outboard that is available. It is 90kW nominal so at cruise it will deplete a 90KWh battery in an hour. The 85kwh battery pack in a Tesla weighs 540kg.

So you have a powertrain weighing 700kg plus. You have an endurance of 1 hour at cruise (imagine this engine on say a Haines Hunter 20 foot planing boat maybe 25knots at its nominal power).

So you have an engine that:

- Weighs 700kg (the full weight all the time)
- Goes about 25NM and then is completed depleted at planing cruise speeds.
- Will then take 2 -10 hours to charge and obviously can't be done on the water
- Based on the current premiums of tender electric motors vs outboard will costs 2.5-3x the price of a petrol outboard.
 

oldgit

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The average majority of small speed boats.
Spends 99.99 % of its time either moored/ on trailer or in the dry stack.
It is launched and whizzes off a very short distance, indeed possibly only at few miles, goes round in circles, might stop for an uncomfortable bouncy beer and sandwich before setting of back home again, its back on the trailer/ dry stack and home for week/ month/ next year depending on weather.
On the rare occasions of decent weather it might repeat the exercise. ?
The only real endurance required would be for waterski-ing schools etc .Simple to get a charging point to the pontoon ?

Audi BEVs will get 350 kW ultra-fast charging
Currently, Audi is introducing its first all-electric model - the e-tron - which will be able to charge from 0 to 80% in around 30 minutes. That's at 150 kW of power, which is industry-leading level for passenger cars. Also, the on-board charging (3-phase at 22 kW is swell too).
However, 150 kW is not the goal, but just a temporary level for the first two cars - the e-tron and e-tron Sportback (2019).
The third model - Audi e-tron GT - built on a second BEV platform and equipped with tech from Porsche, will be capable of charging at 350 kW.
80% state of charge should be achievable in 12-minutes.
 

ontheplane

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Yes but again running cables for these 350kw chargers is major - its seriously hard.

At work we wanted a 150kw charger but there simply wasn't the electrical infrastructure to do it - we had to have 7.2kw instead!

The cables are thick, you need a special type of feed and the 350kw will only work on the new 800 Volt batteries.

At the moment, it might work for displacement boats (on a canal I know some hire boats are electric but its for 3mph for 6hrs a day and they can only then moor at dedicated moorings not anywhere they like....

We are not gonna get there soon. I think Hydrogen fuel cells might work better - ability for longer range and quicker refill.
 

gordmac

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350kw at 230v supply is over 1500 amps!
Electric motors may work for sail boats as, in principle, they should sail most of the time and will be used to going very slowly.
 

ontheplane

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350kw at 230v supply is over 1500 amps!
Electric motors may work for sail boats as, in principle, they should sail most of the time and will be used to going very slowly.

Correct - the cables to the units are like small trees. I think actually you can only have a 350kw charger straight off a high voltage supply, not 230v
 

ontheplane

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But charging will always be an issue.

So assuming a car does 40mpg (mid size diesel) and a boat does 2mpg (mid size diesel boat.

My electric car does 280m on a charge, so with the same size battery a boat might do 14m......

Scale up the battery to give a 250 mile range with a 20% margin (so a 300 mile range) it will need a 1340kwh battery - a 67kwh battery for my car is about £18,000. So the battery for the boat would be about £360,000........

A 1340kwh battery even on the fastest charger currently available in normal use in the uk is 150kw so it would take 7hrs to charge from 20-80% and then another 7 hours to charge the rest of the way - and you shouldn’t fast charge for more than about an hour.......

On a normal 7kw car charger it would take 191 hours......

If on a typical weekend half the boats in the marina went out and wanted to charge on a rapid charge overnight for the next day, let’s say 500 boats at 150kw, the marina would need a 75Gigawatt supply - so it would need a Hinckley B hooked up to it!
 

Assassin

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While the option of electric/battery exists, it is eye wateringly expensive.
The future has to eventually include electric trucks. That is when we will get a cross over to boats and acceptable storage/cost.

Electric lorries are already dismissed as a fantasists dream as lories operate on cargo capacity in both cargo weight or volume and often a combination of the two and an average electric lorry would require both fuel tanks removing and replacing with batteries plus another 8 tonnes of batteries in the trailers just to give them a range of 200 miles running at the current limit if 44 tonnes and this reduces the cargo weight by 8 tonnes and the cubic capacity by the volume of the batteries so no hybrid or electric powertrain would be viable on a boat.
 
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