Epic - Electric Hybrid Boat

[gride300]

tesla=an amazing machine.

[SkiTundra]

I emailed a friend who knows the yachting industry pretty well. He said that diesel/electric drive systems are gaining popularity in the larger yachts to the extent that he doubts any new direct drive systems will be built after about 2012. The energy efficiency of the systems is better than direct drive for many applications, they can distribute weight better and do a better job of isolating engine noise/vibration, and new battery technology has allowed them to get to where they can power the drive motors off of batteries for several hours per day. He doubts we'll ever see fully electric ocean yachts simply because of how much electricity these things use and the batteries that would require.

He said these are quickly moving to smaller boats as well (which to him is 50'). He thinks that if battery and motor technology continue their current pace of improvement that within a few years we'll start to see a majority of small inland yachts for lakes and rivers as completely electric. Once we begin switching to diesel/electric drive systems then the switch to grid charged batteries instead of diesel charged will be quick where it's possible simply because purchased grid power is about 1/8 the cost of diesel generated power. He said that they will have solar panels on top but that he doubts solar will advance enough to be a significant source of electricity. The solar is to help out a bit with recharging batteries and as an alternative for emergency power of critical electronics.

[Laptom]

Don't be to conservative or hated guys...

I think the idea is really good. Not a single diesel, lpg or gasoline engine can create the amount of torque that a single electric system of the same dimensions/weight can do. Will this system be perfect?! Off course not, people and technique are still in the tranfer phase. The technique is available. People don't want to pay $4,- a gallon for fun. The gasoline technique is really, really old... I know, if it aint broken, don't fix it. But energy will be the problem of 21st century and we need to move on to better techniques. So give this a chance, perhaps CC will follow.

[DanielC]

I have seen the Edison electric boat at a few boat shows in the Portland, Or area. If I remember correctly, the person at the boat show said it could run most of the day, AT IDLE SPEEDS. Go faster, and the running time drops a lot. I never did get any comments on how long it would run at a reasonable speed. Maybe that information is available on their website. My guess, double the speed, 1/4 the battery life. Double the speed again, 1/16 the battery life. If idle speed is 5 mph, wakeboard speeds you are in the 1/16 battery life area. I wonder how many slalom passes this boat could do before it needed recharging.
The amount of energy that is available from burning a small amount of gas, or diesel in a modern internal combustion engine is huge. The problem is not the motors to drive the boat, it is the batteries that supply the energy to the motor.

[SkiTundra]

Let's think about the energy thing. I can drive a Porsche at 70mph over the hill and through the woods to grandma's house 210 miles away on 10 gallons of gas. Hopefully grandma has a gas station nearby for my return trip. I can I can do the same in a Tesla (assuming grandma also has a recharge station handy). Tesla can power an electric car for the equivalent of about 10 gallons of 91 octane gas energy. How long can you ski on that 10 gallons?

[DanielC]

I can ski for about 2.8 hours, at slalom speeds, or I can pull girls on swivel ski for over three hours.
A little homework for you people who think an electric boat is the way to go.
Go get a motorcycle, and see how far it will go in just a cup of gas. Uphill and everything. After it dies, see how far you can push it. That will give you a real world demonstration on how much energy is in even a small amount of gasoline.
Now, to a boat. Get a row boat. Think you can ski with only one person rowing?
It is really easy to move things floating on water, as long as you move them very slowly. Double the speed, you will need 4 times the thrust to do that.
A car traveling on a level smooth road only needs about 15 horsepower to maintain a constant highway speed, and on an electric car, when it slows down, you can recover a good part of that energy by using the forward inertia to generate electricity, when you are braking. No such regeneration on a boat.
A diesel-electric yacht can gain some efficiencies by being able to run a diesel engine at its optimum rpm for efficiency, using part of the power for propulsion, and part for charging batteries, enabling the diesel to be shut off in harbor. But you are still not going to be able to have any useful range at any reasonable speed running on batteries alone.

[Sinkoumn]

Until we start building nuclear power plants I really don't want to hear about reduced carbon emissions from electric vehicles - displacing pollution from the exhaust of an engine to a coal-plant across town still doesn't change anything...

[SkiTundra]

Daniel, I think I'm missing something in your analogies. The Tesla generates 248 peak horsepower and 276 ft/lbs of torque. The Tesla drivetrain with stock batteries can propel a 2,700lb vehicle at 70mph for over 210 miles with no regenerative braking. EG, it does the exact same thing as 10 gallons of 91 octane gas in a Porsche of similar weight (the Porsche weighs 110lbs more). Now, 248hp is kind of weak for a towboat, until transmission loss is calculated in which case the much simpler transmission of the Tesla drivetrain allows it to produce more power to the wheels (or prop) with less hp. Also, my EX343+Transmission+38g Gas = 1843lbs. I believe the Tesla drivetrain (Batteries+Motor+Transmission) = 1320lbs. My guess is that the current technology Tesla drivetrain would be an approximate equal replacement for a 275hp PCM engine (perhaps a bit more powerful) and would provide the equivalent time on the water of 10 gallons of gas. A few more batteries might up that to 15 gallons of gas and would then be an equivalent weight boat.

BTW, the cost of that 210 miles (or 2 hrs skiing) in a Tesla is $6.06 vs about $19.10 in the Porsche.

Sinkoumn, aren't there 2 Nuclear plants within about 50 miles of St Paul? I'd guess you're using Nuclear generated power for your computer to post on this board.

[zapada]

I can see both points of view. Daniel makes a good point in that gasoline provides far and above more joules of energy per mass than any other available source. Plus gasoline is so portable and availability at this point very good. I'm no expert on how Tesla maximizes the power of electic motor and drivetrain, but they do a great job at it. There is a chance that this is the way of the future, even in the inboard boat industry. I would also say that the energy required to push a boat through water is significantly more than what is required to push a car down the road. The resistance of water makes to comparison too difficult. It would be like driving your car up to a concrete wall and then doing a burn-out for hours on end. Simple physics will show that if you drive a car down the street and then put it in neutral, you will coast for a while. If you attempt that same experiment in a boat you will almost immediately stop. Correct me if I'm wrong, but there are certain things that just work better with light, energy rich gasoline. It will be extremely difficult to move aircrafts off of Jet A fuel, and it will be difficult to move performance boats away from joules rich gasoline.

[SkiTundra]

Power delivered is power delivered though. The prop doesn't care if that power comes from an electric motor or a gas engine. It just sees hp, torque, and RPM's for some period of time.

[Laptom]

Sinkoumn,

Power plants on coal, diesel or other fuels are way more efficient then your power plant in your car. It makes a different when running a car on electricity and getting that power from a coal power plant.
Although I agree with you that to be really efficient, clean and independent we need to find other ways of generating energy. I don't think nuclear energy is the correct anwser, but perhaps for a small interim period.

[bscott]

Isn't the entire US Navy powered by electric motors? Granted, they've got Nuclear reactors for electricity, but they do seem to be able to do it without electrocuting too many folks.

The electric motor propulsion is for emergency or as a backup. Not very efficient or fast. The primary propulsion is from steam powered turbines.

[bobchris]

you boys don't have a clue what your talking about, you really need to understand what a hybrid actually consists of, and that they can run as long and fast as you want as long as there is fuel for the APU that recharges the battery pack and also drives the induction motors if needed. Do you really think that a hybrid bus is being recharged every loop it makes around the city every hour on the day maybe call NYC transit authority and ask them how they do it and how well their class 6 buses are working out for them

Also last time I check the US navy uses gas turbines aka jet engines to power genartors to power electric drive motors, now they do use steam to launch planes on the carries, but steam hasn't been used for propulsion for some time now.

And yes I have a very good understanding how electric vehicles are designed & built and the differences between that and a Hybrid application. Been there designed that, rode in them all day long without ever pluging it in to charge.

[SkiTundra]

bscott is partially correct. Many subs are powered by steam turbines (the steam coming from the nuclear reactors). These are primarily used on UK subs such as the Swiftsure and Trafalgar class subs. Others use the steam to drive generators to produce electricity for electric propulsion which is somewhat quieter and more controllable than direct steam propulsion. Many US subs use a combo system with electric and steam turbines on a single shaft, the electric used as primary and when quiet/control is critical and the direct steam used for high speed. Magnetohydrodynamic propulsion (see Hunt for Red October) is also apparently coming online and uses nuclear>steam>elecgenerator>electricity propulsion.

[DanielC]

The Tesla car, that can travel approximately as far, on batteries as your Porsche does on gasoline, probably only needs about 25 horsepower to move it at a steady 70 miles per hour. Sure, you have over 245 HP available, on the Tesla, but you are not using it.
How fast do you think a 2350 pound 20 foot boat would go with a 25 HP outboard on it?
Although power delivered is power delivered, electric motor HP and gas motor are different in practical use. Most electric motors produce maximum torque when stalled. A stalled gas motor produces absolutely no torque. Yes, I know the difference between HP and Torque. No RPM. No Hp, but the torque of a stalled electric motor will still get you moving.
By the way, there is an electric 1200 Datsun running around some drag strips around here, that has beaten many, many big block V-8 cars.
I do not see an electric power train, and batteries in a boat being able to supply the same running time and speeds as a gasoline power train, and fuel tank. Especially if you are trying to keep similar sizes and weights.

I am in favor of nuclear power. France makes a lot of their power from nuclear energy, why can 't we. I believe there would be a lot more nuclear power plants if the first use of nuclear power was not to end World War Two, a war we DID NOT START!

I am not so sure about the efficiencies of burning a fossil fuel to make electricity. Again based on my experience here in Oregon, the fossil fuel burning power plants are located in eastern Oregon, away from the population, and the electricity is moved through wires, at a loss, to western Oregon. I think it would be more efficient to start encouraging new construction to use Natural gas for household heating needs, rather than burning gas to make electricity, to move the electricity several hundred miles, to inside the home, to make heat again.

Make no mistake about it, I am all for the reduction of fossil fuels I use. That is one reason I use an Aerostar van for a tow vehicle. It moves my boat more economically than a big full sized SUV can. not as fast going up a hill, but I can give that up.

Worst case scenario. My boat uses 3.5 gallons of gas per hour. I get four people for a half day of skiing. Four hours of boat actually running. 14 gallons of gas, $60 dollars for the day, fuel costs, at last Summer's prices. Divide by the four people, $15.00 per person.
What does a 90 minute movie cost? How about a live show at a theater? How much for a Concert? Do you think your wife or girlfriend (or male counterpart) could go shopping for half a day, and spend only $15.00?