1 - 20 of 63 Posts

Allmayer-Beck

·
Registered
Joined
·
5 Posts
Discussion Starter · ·
Dear Community,
My name is Maximilian Allmayer-Beck and I am consulting a start up from Barcelona, which is working on an alternative way of generating energy on sailboats. The newly developed technology allows you to generate energy from the movement of the boat, store it and later on of course use this energy. Furthermore the device is waterproof, salt resistent and very low maintenance is needed. The whole device consists just of a box with two cables coming out. You can store the box for example under a bed and just plug in the cables to your battery.

However, what would really interests me now is how big such a device could be?
a) 100x40x40
b) 75x30x30
c) 50x30x30

How much it could weight?
a) 30 kg
b) 20 kg
c) 15 kg

How much power it should be able to produce?
a) 0,5 A ( = 6 watts)
b) 1 A ( = 12 watts)
c) 1,5 A ( = 18 watts)

Concerning the last point you have to keep in mind that solar power can produce more watts but only for a few hours a day whereas this device can produce power during 24h.
Any other feedback would be also very kind!
Thanks a lot!

tommays

·
Registered
Joined
·
4,304 Posts
I have a high quality bare minimum solar system which peaks out at 2.5 amps and combined with my really low energy needs works out fine on a 29' boat that lives without any shore power on a remote mooring

It also keeps my two battery's very happy even during the winter when the boat is on the hard and NOT moving

The next step for us would be a small Engel drop in refrigeration unit which then raises the energy budget massively at which point I would have to add a bunch of stuff

capecodda

·
Registered
Joined
·
1,862 Posts
Max, good luck with your project.

You'll find if you search around that many cruisers are using 50 to 200 or more Amp hours per day particularly if they have DC refrigeration (lots of variation around this based on climate and particular systems). Mostly 12 volt systems so you can do the power calculations.

Given the choices, even at 1.5 amps running 24 hours, you'd be making us 36 Amp hours. Not meeting all the needs, but making a good dent.

I don't think the size or weight is an issue if you can find a place to get the system low as to not greatly upset center of gravity. If I'm guessing right about your technology, the thing counts on rocking motion of the boat. If that's so, I think you'll find that most cruisers are sitting in the calmest harbor they can find most of the time, then taking a big trip, then sitting still again. That may be the biggest issue (again, if I'm guessing right about how it works).

Many of us wish there was a way to generate power without a wind generator, plugged into a dock, a solar panel, or some sort of engine running. Appreciate any effort to accomplish this.

Bene505

·
Joined
·
3,843 Posts
It must be perfectly quiet.

The worst sound is one that comes from a rocking motion. You lay in your bunk, the boat rocks, and you hear a loose item go click, or a can roll in the cupboard, or a pot lid make a small bang. Then with every rock you dread what's coming, like the Chinese water torture. You know it's coming... here it comes... click!... then rock the other way... then rock back, here it comes... click!

The click seems loader than it is because you expect it and everything else is quiet. You dread it each time as you try to sleep. Even though it's a small click or bang it's the loudest thing on the boat. And hear it comes... CLICK!... then rock the other way... then rock back, here it comes... CLICK!... then rock the other way... then rock back, here it comes... CLICK!... then rock the other way... then rock back, here it comes... CLICK!... then rock the other way... then rock back, here it comes... CLICK!... then rock the other way... then rock back, here it comes... CLICK!... then rock the other way... then rock back, here it comes... CLICK!... then rock the other way... then rock back, here it comes... CLICK!... then rock the other way... then rock back, here it comes... CLICK!... It's madness I tell you, madness!!

You get the idea.

Regards,

denverd0n

·
Registered
Joined
·
1,474 Posts
Well I think the obvious answer to how big and how heavy would be, it depends. I'd be willing to put up with a bigger, and heavier, device if it produced more electricity. If it is the size of a box of tissues, weighs little, and costs little, then I won't mind if it produces little electricity. If it takes up the entire space under a berth, weighs a ton, and costs thousands, then it had darned well better produce almost all the electricity that I need!

·
Joined
·
626 Posts

Don L

·
bell ringer
Joined
·
6,293 Posts
However, what would really interests me now is how big such a device could be?
a) 100x40x40
b) 75x30x30
c) 50x30x30

what are the units of measurement here, inches, centimeters?

How much it could weight?
a) 30 kg
b) 20 kg
c) 15 kg

if the power produced was worth it none of these weights are an issue to me

How much power it should be able to produce?
a) 0,5 A ( = 6 watts)
b) 1 A ( = 12 watts)
c) 1,5 A ( = 18 watts)

at such low output the unit would have be almost free as I could add another panel to my solar at less than \$1/watt

Concerning the last point you have to keep in mind that solar power can produce more watts but only for a few hours a day whereas this device can produce power during 24h.

true, but that is why I have batteries to store the power so I don't really care if I'm not making power at night
What happens to power output when it is calm out since it requires movement?

Allmayer-Beck

bobmcgov

·
Joined
·
1,142 Posts
I would really like to see some numbers coming from the little box with wires. There are lots of issues with accelo-generators that have quashed this idea for, oh, the past 150 years. The basic idea works -- and it works well on very small scales (self-winding watches) and very large scales (tidal generators). The keys there are minimal output energy requirements (wristwatch) or extremely powerful energy inputs (a few million tons of moving water).

Work is work: a force applied over a distance. To reap watt-hours from an accelo-generator, you need a very heavy weight, or a very large input acceleration, or a really long stroke. Preferably all three. One horsepower (~750W) is equal to lifting 550lbs one vertical foot in one second. Let's say the weight in the box is 15kg (33#), the pendulum stroke is 8", the acceleration under frisky conditions is 0.5g, and the conversion efficiency factor is 50% (that's extremely generous). Back of the envelope calcs suggest 2.75 watts out of such a device., or 0.2A.

Now where do you put it? Boat motion is greatest outboard and at the ends -- but you don't want heavy stuff or accelerated masses on the ends of your boat, or outboard. There's the issue of hysteresis: the device is going to lag behind the phase motion of the boat, esp. in erratic seas, cutting efficiency further. Most boats spend most of their time in a marina or harbor, chosen and designed specifically to minimize motion from waves.

It's a neat idea, I guess; but I'm always deeply suspicious of fractional horsepower electrical generating devices, especially on boats. How about doing what inventors used to do: Build the magic box, put it on a sailboat, show us third-party verified power outputs when attached to an actual load, and then go looking for someone to capitalize & manufacture it? I'll be thrilled if it works, might even buy one, but til then it's just mo' RE vaporware.

capta

·
Master Mariner
Joined
·
9,480 Posts
Since I've got a bigger boat than many on here, size it not much of a concern to me. If this unit is a one time install, requiring no maintenance and removal/repair/re-installation, then weight isn't a big factor either. My daily energy use is probably not that much different from a smaller cruiser, so it comes down to output. If your unit will produce a maximum of 1,5 A ( = 18 watts) underway, what could it possibly produce in a calm anchorage or mooring? For most cruisers, I doubt that 1,5 A ( = 18 watts) 24/7, even at anchor, would be worth a whole lot of money or the space.
Should you be able to get an average of 10 amps of 12 volts in a calm anchorage or mooring, then I think everyone here would scrimp, save and sell their mother in law, to get one aboard.

Allmayer-Beck

·
Registered
Joined
·
5 Posts
Discussion Starter · ·
First of all, thank you so much for your quick response and the valuable feedback you gave me so far! In order to quickly response to a few things now:

[email protected] Bene55 --> Yes, the device is absolutely quite without making any noise!
2. @capt vimes --> thank you very much for the link!
3. In order to answer the rest of the questions I will talk to my technical team tomorrow and I for sure can provide you with more details by then.

Thanks again for now!

krisscross

·
Registered
Joined
·
4,170 Posts
How about installing it outside or under your boat, under water? Then the weight would not matter much, and any noise would be easier to take. You could place 2 on both sides of the hull for maximum movement and balance.

Allmayer-Beck

capt vimes

·
Registered
Joined
·
626 Posts
How about installing it outside or under your boat, under water? Then the weight would not matter much, and any noise would be easier to take. You could place 2 on both sides of the hull for maximum movement and balance.
more wetted surface, more drag...
honestly - the best place to put such a device would be the mast top...
there you have the biggest movements and accelerations in all directions...
if it would not be for the weight punishment placing it high up...

·
Sea Sprite 23 #110 (20)
Joined
·
3,217 Posts
more wetted surface, more drag...
honestly - the best place to put such a device would be the mast top...
there you have the biggest movements and accelerations in all directions...
if it would not be for the weight punishment placing it high up...
But.. if mounted to the area with the most amount of movement, it would not need as much weight to get the same amount of energy (assuming a weighted pendulum effect is going on)

Allmayer-Beck

krisscross

·
Registered
Joined
·
4,170 Posts
more wetted surface, more drag...
honestly - the best place to put such a device would be the mast top...
there you have the biggest movements and accelerations in all directions...
if it would not be for the weight punishment placing it high up...
How about a nice torpedo shaped weight at the bottom of a keel? Might actually improve sailing and have plenty of movement.

Allmayer-Beck

capt vimes

·
Registered
Joined
·
626 Posts
How about a nice torpedo shaped weight at the bottom of a keel? Might actually improve sailing and have plenty of movement.
issue is that the keel (ballast) does not move very much...
it is quite close to the center of gravity around which the boat revolves, jerks, yaws and pitches (or should i write Bitches, since i used the term jerk as well... )...

manatee

·
Registered
Joined
·
1,033 Posts
more wetted surface, more drag...
honestly - the best place to put such a device would be the mast top...
there you have the biggest movements and accelerations in all directions...
if it would not be for the weight punishment placing it high up...
I like the top-of-the-mast idea. Make mine the 'Deluxe' version, combination bird-repeller and active radar repeater, something to make a Cal 22 look big as an aircraft carrier to all those big boats with lousy watchkeeping standards.

Allmayer-Beck

krisscross

·
Registered
Joined
·
4,170 Posts
issue is that the keel (ballast) does not move very much...
it is quite close to the center of gravity around which the boat revolves, jerks, yaws and pitches (or should i write Bitches, since i used the term jerk as well... )...
I would think that the movement of the keel bulb would be similar to the movement of the top of mast, just along a smaller radius, but with the same momentum. Classic lever/pivot point situation. It is likely the momentum that is translated into electricity in those kinetic energy gizmos, not merely the radius of the movement.

Allmayer-Beck

bobmcgov

·
Joined
·
1,142 Posts
I would think that the movement of the keel bulb would be similar to the movement of the top of mast, just along a smaller radius, but with the same momentum. Classic lever/pivot point situation. It is likely the momentum that is translated into electricity in those kinetic energy gizmos, not merely the radius of the movement.
Nope. Teh box does not care how heavy or light the item it is attached to is. The controlling momentum resides in the weight (piston, pendulum, whatever) inside the magic box. What matters is acceleration, which is the rate of change of velocity, which itself is a combination of speed (a scalar) and direction. So the more an item changes speeds and/or direction, the greater its acceleration. The masthead and the keel bulb have the same period; that is, they complete one cycle of pitch or roll in the same length of time. But the top of the mast experiences far greater acceleration.

Now, take that acceleration and multiply it by the mass of the pendulum in the gizmo, and you have a force (F=ma). Multiply that force by the distance the gizmo's weight can shift within the bounds of its box (called 'stroke'), and you have F x d=Work; divide that by time, you have power. Multiply that power by time -- usually a different unit of time than time used to measure power itself -- and you have energy, like amp hour or watt-hour, which is what you store in yo' batteries. So a typical scenario (ignoring dissipative losses) for the OP's magic box might be:

Battery Juice = ((m*a)*d/t1)*t2 = ((15kg*4.9m/sec^2)*0.3m/2sec) = 11 Watts; 11 Watts*24 hours/day = 264 Watt-hours, or 0.26 kWh/day.

That's about what you would see from one 50W solar panel operating 5 hours a day.

Isn't physics fun?

weinie

·
Registered
Joined
·
601 Posts
Nope. Teh box does not care how heavy or light the item it is attached to is. The controlling momentum resides in the weight (piston, pendulum, whatever) inside the magic box. What matters is acceleration, which is the rate of change of velocity, which itself is a combination of speed (a scalar) and direction. So the more an item changes speeds and/or direction, the greater its acceleration. The masthead and the keel bulb have the same period; that is, they complete one cycle of pitch or roll in the same length of time. But the top of the mast experiences far greater acceleration.

Now, take that acceleration and multiply it by the mass of the pendulum in the gizmo, and you have a force (F=ma). Multiply that force by the distance the gizmo's weight can shift within the bounds of its box (called 'stroke'), and you have F x d=Work; divide that by time, you have power. Multiply that power by time -- usually a different unit of time than time used to measure power itself -- and you have energy, like amp hour or watt-hour, which is what you store in yo' batteries. So a typical scenario (ignoring dissipative losses) for the OP's magic box might be:

Battery Juice = ((m*a)*d/t1)*t2 = ((15kg*4.9m/sec^2)*0.3m/2sec) = 11 Watts; 11 Watts*24 hours/day = 264 Watt-hours, or 0.26 kWh/day.

That's about what you would see from one 50W solar panel operating 5 hours a day.

Isn't physics fun?
well that ends that!

·