"the first real fast electric yacht in the world"

[MYStargazer]

http://www.cadiayachts.com/


Sadly not much info on batteries and range.


Thoughts?

 

[Whitelighter]

Unless I'm mistaken the donor boat is an Élan 48 Ht

So at least all the other bits are a known. Looks interesting.

 

[Grampus]

Can't help but think this is a totally unreal pipedream. If a boat needs a pair of 300 hp engines to push it along at say 25 knots then it will need the same power input regardless of the energy source.

The sad point is that the energy stored in a battery is pretty small compared with that stored in liquid fuel, for example, a car starter battery has about as much energy stored as a cupful of petrol and even with modern polymer batteries energy density capability is only a factor of about 3 or so better.

I just don't think this is a real world situation, the sort of performance you get from the likes of Greenline is what is avhieveable there is no magic, it's just physics.

(I am not against the electric vehicle ideal, I built my first one in 1973, but just look at the power and performance needs of cars to see how real world a powerful mobo can be.)

 

[Whitelighter]

But by the same arguement there are cars such as the tesla model S that out perform 300hp petrol cars and mange usable battery range (300 miles on the top spec car)

A boat has much much more room for batteries than a car so I don't see it as Unpheasable. The limitation is the cost if battery technology but that is coming down all the time. Think about the volume and mass of a couple of 8 cylinder diesel lumps. That's a lot of volume and weight for batteries. The drives are in the same place and electric motors are very compact.

 

[Andy Bav]

Website is an invitation to invest in a start up. Coincidentally the "stock exchange" you would purchase the shares is also a start up.... By the same founder...

If the technology can work. Great. As an investor... I'm out.

 

[Grampus]

Of course you can build a vehicle/vessel with given performance and range, but a boat needs about 200 miles range say, that's 20 knots for 10 hours, equivalent to around 400 kilowatts for 10 hours, or 4000 kilowatt hours of stored energy - pretty big battery bank.

Energy density of lead acid is about 50 Watt hours per kilogram and for the best available polymer batteries, about 150 Watt hours per kilogram. So for 100 Watt hours per kiolgram you would looking at 40 tonnes of battery.

Reduce the speed to 4 or 5 knots and the demand for power is minimal, hence the Greenline type specs of range and speed.

I think it is just a fishing expedition looking for gullible investors.

 

[jrudge]

Bulgarian company registered in Belize. ... neither really inspire confidence!


It is interesting the batteries "only" weigh 40 tonnes ( given a 65 foot boat weighs 30 odd anyway) can you imagine how big the charger would need to be!

The concept is interesting to a point. Electric cars are now a reality to a degree, but have the same problems. They are great for moderate distances, but lousy for long ones ... and given the recharge time is significant multiple hops does not really solve the problem either.

If marina hopping in the Med then great, but would you buy a boat that could only do say 50 miles?

 

[MYStargazer]

If marina hopping in the Med then great, but would you buy a boat that could only do say 50 miles?

Hopping distances far greater in Med than UK. Balaerics out of reach for starters.

 

[MYStargazer]

If marina hopping in the Med then great, but would you buy a boat that could only do say 50 miles?

Hopping distances far greater in Med than UK. Balaerics way out of reach for starters...

 

[rafiki_]

But by the same arguement there are cars such as the tesla model S that out perform 300hp petrol cars and mange usable battery range (300 miles on the top spec car)

A boat has much much more room for batteries than a car so I don't see it as Unpheasable. The limitation is the cost if battery technology but that is coming down all the time. Think about the volume and mass of a couple of 8 cylinder diesel lumps. That's a lot of volume and weight for batteries. The drives are in the same place and electric motors are very compact.

Jez, the Tesla won't give that sort of range unless running downhill. Real world range about 120 miles. Still quite usable for a car, but think how quickly a boat will consume energy at anything above displacement speed.

 

[wipe_out]

I just can't see it working as all electric and at speed.. The numbers just don't add up.. Hybrid yes, full electric no.. Not unless they have some miraculous new electricity storage facility and can harness lightning..

 

[Hugin]

But by the same arguement there are cars such as the tesla model S that out perform 300hp petrol cars and mange usable battery range (300 miles on the top spec car)

The Tesla car only achieves it's 300 miles range at modest speed. Even a supercar only need something like 15kW to roll along at 50mph. A boat like the one described here would get around 4 knots for 15kW..... obviously far from planing speed

A boat has much much more room for batteries than a car

True, but not really relevant.

The limitation is the cost if battery technology but that is coming down all the time.

No, the limitation is weight...... especially for a planing boat like this. Most of the Teslas have a 85KWh battery which allegedly weighs around 600kg. Even if you could find a billionaire that will pay whatever it takes you still cannot build a 30knots planing yacht with a range of, say 200nm..... impossible!

Think about the volume and mass of a couple of 8 cylinder diesel lumps. That's a lot of volume and weight for batteries. The drives are in the same place and electric motors are very compact.

Let's do the math. An Elan Power 48 is 18tons dry, add half fuel and water + 4-5 people + supplies and we're at 20tons. To achieve a 25 knots cruise you need around 450kW...... not a problem when you have 2 Cummins QSC engines and up to 1800 liters of diesel.

So out goes the Cummins diesels and the ordinary batteries = 2tons saved. Aiming for 20tons we can also in-calculate the removal of "half-fuel", so another 750kg removed. This gives us 2750kg for batteries, rounding up a little we can throw in 5 Tesla battery packages = 425kWh total. Of course the electric motors and power electronics also weigh something, but let's be generous today.

Assuming we start with fully charged batteries and can run them completely dry (not advisable at sea) these 5 battery packs gives us an approximate 57minutes endurance at 25knots; no reserves at all! And it's even worse at 30knots..... endurance now 39minutes... still without any reserves

Of course we can add more battery packs, but the weight goes up really, really fast at 600kg per 85kWh. It will require more and more power to even get this brick up on plane. It should be mentioned that the Tesla battery pack is by far the best available on the market with a specific energy density of 145Wh/kg. Other electric car batteries generally struggle to deliver even 100Wh/kg.

It's a pipe dream.

It might make sense to build a slender electric displacement yacht with a 10 knots max speed; but this fast electric yacht project makes no sense at all

 

[vas]

interesting stuff, thanks guys!

what would be the "contribution" of some solar panels in this equation?
Say 20sqm would help a 10kn slender displacement yacht of 50odd ft to ... ???

Recharge it's batteries in the Med sun enough to run the windlass twice AND move 400yrds to the other side of the bay once a day (sort of thing?)
ah and run 2 150lt fridges!

in a week charge enough to move 10nm at 4kn to the next marina/bay...

I guess unless el. production yield and storage systems improve dramatically, it's a non-starter...

cheers

V.

 

[Wiggo]

Interestingly, 2 654kW engines are using 1300 units per hour. Now the cost of leccy here is about 13-15p/unit, so even if it is 100% efficient and you're paying domestic prices in the marina (which we don't), it still costs £150-200/hour to run the thing, or not vastly different to the cost of the diesel version. Mid cruise, I can pop into a marina and put in another 1000l of diesel and pay for it in 15 minutes. Can't quite see this one recharging at that speed. And you're a bit stuffed next morning if the neighbour's aircon tripped the pontoon leccy...

 

[Hugin]

what would be the "contribution" of some solar panels in this equation?

Marginal. Hardly worth mentioning. Solar panels on boats are mostly a marketing gimmick aimed at those aspiring to a green image!

The Greenline 40 can be ordered with 6 solar panels more or less covering its entire (quite substantial) roof area. On a sunny day these panels yields an astonishing 1400W total. I don't know how fast an 8t boat can go on that, but I'd be surprised if it was more than 3 knots. The panels are optional, priced at 7000eur + VAT. For most boat owners that turns out to be some very expensive electricity.

Leave the solar panels ashore. They are more use there.

Say 20sqm would help a 10kn slender displacement yacht of 50odd ft to ... ???

Nothing really!

OTOH, that slender displacement cruiser becomes viable if it has a modest diesel generator as Range Extender

Some quick back-of-a-napkin calculations: LWL = 52ft, Beam = 13ft, Dry displacement 16tons including ~3 tons of batteries of the Tesla type (=425kWh). Propulsion: 200kW electric motor + 50kW Diesel-GenSet as Range Extender

6 knots require ~16kW = Battery range of 159nm
7 knots require ~21kW = Battery range of 141nm
8 knots require ~29kW = Battery range of 117nm
9 knots require ~42kW = Battery range of 90nm
10 knots require ~63kW = Battery range of 67nm
11 knots require ~102kW = Battery range of 45nm
12 knots require ~16kW = Battery range of 28nm

It's really just an estimate - the formula I used for calculations doesn't take into consideration that the hull stay slender as battery weight is added. Weight adds very little extra drag to a displacement hull as it just sink in a few extra inches.

Notice that the Range Extender alone will allow 9knots as long as there is diesel in the tank and 10 knots could be sustained for more than 24hours if the Range Extender provided the majority of the electricity.

Tesla's batteries are rumored to cost around $250/kWh (which doesn't mean Tesla will sell them for that), so $110.000 could in theory equip a boat like this with batteries. Expensive but not completely insane!

 

[MapisM]

Can't help but think this is a totally unreal pipedream.

+1.
Fully electric propulsion is still far from being practical in boats which are ideally suited for it, namely full displacement vessels.
It takes a great deal of optimism (and/or alcoholic beverages) to even think of using it on planing boats, where weight is #1 enemy...

 

[grumpy_o_g]

Given that a decent hairdryer seems to trip the electric in a lot of marinas, and that's assuming that no-one has unplugged your boat because it's 10 feet nearer their boat than the next free socket then I think there's a few other issues to resolve as well yet...

 

[longjohnsilver]

+1.
Fully electric propulsion is still far from being practical in boats which are ideally suited for it, namely full displacement vessels.
It takes a great deal of optimism (and/or alcoholic beverages) to even think of using it on planing boats, where weight is #1 enemy...

Absolutely, not a hope with current battery technology. As the company asking for investors well knows.

 

[oceanfroggie]

Seems an engineering joke. Another pipe dream that doesn't compute.

 

[MYStargazer]

Update on their website...

http://cadiayachts.com/events-and-n...ct-about-to-reach-a-new-stage-in-june-2014-14

Any day now, then!