TKO Electric / Solar Concept

Indeed, somewhat of a struggle!

If we assume that the boat runs at 50% power for the four hours required endurance, then that's a 36 kWh usable energy battery. If using deep cycle lead acid, then usable energy will be at best 80% of rated energy, preferably down around 60% of you want best battery longevity. This means the minimum battery capacity needs to be around 45 kWh. If the battery is deep cycle lead acid, then the battery weight alone is going to be around 1400 to 1500 kg (roughly 3100 to 3300 lbs).

If the batteries made up 50% of the total proposed hull displacement of 1300 lbs, then they would only have a usable energy of around 7 kWh or so, enough to cruise for around 45 minutes at half power.

 

ELECTRIC DESIGN by TKO

Design

6 batteries at 240 lbs total
2 motors at 50 lbs
6 PMA's at 12 lbs total
---------------------------------
(1) 6 batteries run the Motor
a. The shaft turns and drives a sprocket that turns the PMA generators
b. The shaft is also connected to the prop
c. We suggest a larger props - as long as it is turning, you do not have drag problems.

(2) 6 PMA generators
a. as they turn they easily produce 12 volts
b. as RPMS increase each one can produce up to 1000 watts
c. These charge the batteries, as well as run electric on the boat
d. The design allows the motors to run while PROP nuetral / not engaged, thus charging while standing still
e. Each PMA is individually attached to the batteies, thus no excessive wiring is needed

Note: Each PMA generator output is unregulated. You should be sure and run a 20 or 30 amp fuse on the output to prevent damage to the unit if your load becomes excessive. Also, consider using a charge regulator so your batteries don’t become overcharged. ** On our test stand with one 12 Volt battery connected one PMA produced 15 Amps at 2000 RPM.

Engines: Please see IKANOSTECH.COM
PMAs: Please see WINDBLUEPOWER.COM

Your feedback is welcome.

 

Let's work through some rough numbers and see what pans out:

240 lbs of deep discharge lead acid batteries at around 30 Wh/kg energy density gets you a total stored energy of around 3.3 kWh, and a usable energy of around 80% of this at best, so you have just 2.64 kWh of energy available.

You have two 9kW motors, that if run at 50% of maximum power will drain that 2.64 kWh of available energy in around 18 minutes, even without the added power drawn by the PMAs.

Using generators driven by the same motors that are powering the boat is NOT adding energy to the system, it's subtracting it, making the endurance and efficiency worse by drawing more power from the batteries.

The bottom line is that there's nowhere near enough stored energy in these tiny batteries to run such a system for very long unless you introduce another prime energy source, like a fossil fuel generator (which would turn the boat into a hybrid).

 

Imho, it's more like:
- 300 lbs for 6 batteries, but you'll need much more, as Jeremy Harris is trying to tell you.
- 40 lbs for motors
- 400 lbs for wind turbines (10 x these for a total of 6 kW - where do you put them?)
- 10 lbs for wiring
- some 10 lbs for electronics,
for a total of around 750 lbs for the basic equipment indicated by you. Leaves just 550 lbs for the structure of a 21 ft boat, a pretty fragile number.
You should always try to stay on the safe (heavier) side when estimating weights. By doing so, the disappointments will be smaller when the boat is built.

The wind turbines shown at windbluepower.com will give up to 600 W. If you need 1 kW wind turbines, then you'll have to use something like this: http://www.hummerwind.com/hummer_1kw.htm - 140 lbs weight each. It's 840 lbs for 6 WT's.

So the point is - the initial power and energy storage estimates look wrong, as well as the initial weight estimate. Actually the boat type is wrong - a planing boat needs as little weight as possible and is very sensitive to any weight increase, which is incompatible with what hybrid (solar or wind electric) option gives.

Check this thread too: http://www.boatdesign.net/forums/powerboats/another-hybrid-success-43764.html, with some data taken from comparative sea trials of an existing hybrid vs. conventional boat. The conclusion - the added weight and losses of the hybrid drive has made the fuel efficiency worse, when compared to the "basic" (non-hybrid) version of the same boat.

Cheers

 

PMAs Perminant Magnet Alternators

PMAs are only 6" by 6" and they deliver a bang for the buck

The DC-512 model is best suited for motor driven applications when used in a generator setup. Reaches 12 Volts at 650 RPM The chart below represents actual output on a test stand. Voltage readings were recorded with the circuit open (No Load) while Amperage was recorded with the output shorted (Max Load). Your system setup will determine what output you will see in the “real world”. For example a dead battery will pull much more current similar to the shorted output reading than will a fully charged battery. Also the voltage will rise until it meets the voltage of your battery and then level off as the battery is “absorbing” the excess voltage as it charges. This unit can handle up to 10,000 RPM. The output is unregulated. You should be sure and run a 40 or 50 amp fuse on the output to prevent damage to the unit if your load becomes excessive. Also consider using a charge regulator so your batteries don’t become overcharged. On our test stand with a 12 Volt battery connected the PMA produced 40 Amps at 2000 RPM.

 

Ok, my fault, I didn't understand you correctly. No wind turbines, just the generators taken from the producer of wind turbines, connected to the IC engine shaft. Is that correct? The problem of the increased weight on a planing craft remains.

And one other question still puzzles me - why? Why charging batteries from an internal combustion engine, and then discharging them again into electric motor and props?

 

Are we at all sure that these generators are to be coupled to another prime mover, though? Clearly there's nowhere near enough stored energy in the proposed battery pack to run the boat for more than a very short time, but if there's to be an internal combustion engine driving the generators then one has to ask why bother with the electric drive at all?

I've worked on a small series hybrid drive, with a buffer battery, and it wasn't very efficient, probably about the same as a hydraulic drive I think. The only advantages it gave were being able to position the engine/generator set up in the bow, with the small battery pack aft. The electric motor was slim enough to fit under the sole, which happened to make life a bit easier in terms of the layout of this particular boat.

 

Proven results from LOON pontoon boat

I will post the proven results from the LOON pontoon boat.

My intent is to augment the design with (2) 12 HP that produc equal to 48 HP deisel each. These motors were tested by NASA ...

 

In what sense are 12 HP electric equal to 48 HP diesel?

 

Could you just clarify the total energy sources that you intend using, please?

At the moment, it looks as if the only energy source you have is the charge in the fairly small deep cycle battery array, yet you have mentioned the use of generators and I'm not sure where you're going to get the energy to drive the generators from.

The Loon boat data illustrates the energy problem for an electric boat well, as although it has a large solar array (a 1000 W array takes up around 5 m², or around 54 sq ft) it still needs charging, even though it only has a 4.1 kW peak motor. Even the big solar array can only provide around 1/3 of the power the boat needs at cruising speed. Note also that, like all electric cruising craft, it is a slow speed vessel, something that's essential to allow the use of the small motor. The Loon also has a pretty big battery array, around 10 to 12 kWh I believe, which is about three times the capacity that you're proposing.

 

None at all. It's a complete myth that arose back when people first started using direct drive electric motors of relatively low power and thought they out-performed their true power rating. It turned out to be rubbish, as the only efficiency gain was in not needing a gearbox, yet it still gets quoted as if it were true by people who should know better.

There's no practical difference in terms of motive force between a properly matched 12 hp electric motor and a properly matched 12 hp diesel or petrol engine - all will give the same performance if using a transmission and prop that's correctly matched to the boat.

 

Thanks Jeremy. I wanted to hear that from TKO, just to make sure he understands the concept of HP and how to evaluate the effective power a boat needs to move at a certain speed. I am not taking it for granted after all this discussion, as I am not taking for granted that the concept of energy/fuel efficiency (and how to evaluate it) is well understood by the designer of the boat.

 

I'm struggling to understand where TKO plans to get the energy from to drive this boat, TBH, as the battery bank clearly doesn't have enough capacity, a deck mounted solar array on that size of boat would only provide a small percentage of the energy needed and we don't seem to have any indication as to what sort of energy source is going to drive the PMAs that have been suggested as a additional power supply.

 

Proven use of the same motor in catamaran's 35 feet long in open sea conditions show this motor is equal to 48 HP deisel. My boat will be 21 feet long and have 2 motors

 

Sorry, but all that shows is that the 48hp engine installation was grossly inefficient, probably with a poor choice of propeller, as that's usually the greatest source of lost power in any powered vessel. Power is power, there's no difference between 1hp produced by an electric motor and 1 hp produced by a diesel engine; they are both 746 watts.

Getting back to your boat, can I ask again where your primary energy is coming from?