Building the Electric Sternwheeler Tesla's Revenge

[newhaul]

Originally Posted by wildshore

Actually what you're seeing there is Floating Empire I, which was our original test bed. Tesla's Revenge will have a conventional barge hull.

[a64pilot]

The generator came from your not going to have enough bank or charge source for propulsion. This was posted in another thread to give an idea just how much power there is in just 700W, less than 1 HP and not nearly enough to move your boat for instance

https://www.youtube.com/watch?v=S4O5voOCqAQ

.
I am not proposing a generator to charge a battery bank to move your boat, that's inefficient, best to drive the boat directly from the Diesel engine.
However to use an example my little Nexgen 3500W generator at max output burns a half gallon of Diesel an hour that is electrically 5 HP, mechanically its much higher, just I don't know what off the top of my head, but in a slack wind condition you ought to be putter along at a quart an hour and make 3 or maybe 4 kts, and you really of course can use old Mcdonald's french fry grease as fuel, or any other well filtered cooking oil.
That isn't fossil fuel.
Unfortunately the cruising community has found that on average a wind generator just doesn't supply much power, especially not in a sheltered anchorage, where you will be all the time as I'm sure your not going out into the open ocean with 15 kts of wind.
However built right, your an almost perfect Solar collector without masts and rigging to shade them, make them tiltable and use a stern anchor too so that you can correctly position your panels and you can get a lot more power than a sailboat can.

If your going to move much at all, have you considered re-purposing an old sailboat? They can be had for free and nothing moves through the water with less resistance than a sailboat. Can the mast and rigging that you don't need and mount a large Solar array, due to it's ability to move through the water with little effort, you have a much, much better shot at making electric propulsion work

[minaret]

Commercially available off the shelf today at reasonable prices.


Efoy Comfort Fuel Cells




Ye olde fuel cell.

[minaret]

Amp Hours 210
Nominal Voltage 12V DC
Maximum Power 105W
Charge Current @ 12 V 8.8A

Nominal Consumption / kWh 0.24 Gallon
Weight 18.7 lbs.
Size 17.44"L x 7.95"W x 11.34"H
Operating Temp -4°F to +104°F


$5898.99



Yeah I know it's not much, but one must remember it runs 24 hrs a day soundlessly, rain or shine, wind or calm. A potential good addition to solar and wind.

[minaret]

Efoy Fuel Cartridge M10 - 2.64 Gallon





Fuel for fuel cell.



"Efoy fuel cartridges are real bundles of energy. They may not weight much but they are packed with energy. An M10 fuel cartridge, for example, weights only 19 pounds but contains enough fuel to produce 11.1 kilowatt hours of energy. "



Lets not forget they've been using electric's on things like tanks and submarines since WWII, often diesel-electric. Believe Ferdinand Porsche designed the first gas-electric tank.

[a64pilot]

6K for 100W is a lot.
You can make the argument that it is really more like 400W+ since it can run for 24/7 though, still, it's $6K
I bought 1250W of panels for $625, and his boat ought to have the real estate for a whole lot of panels.
I bought left over panels from a large installer and paid .50c a watt

The more I think about it, the more a "free" 30' sailboat makes sense, for electric propulsion and for the Great Loop and for expenses, already is a boat and has all the required systems in place already

[wyb2]

Jeez, we start with how paddle-wheels are crap, then we switched to why solar/electric is crap. Obviously props are the "right" way to drive a boat given modern tech, that's why almost all modern boat utilize it. Obviously combustible fuel is the "right" way to store energy on a boat given modern tech, that's why almost all modern boats use it.

Not all projects have to be about doing it the "right" way. If you end up with a functioning product that is fun to use and was fun to build, you've succeeded.

An all solar setup isn't about traveling fast or efficiently, it's about free fuel. Any sailor should be able to appreciate that.

Fair enough to point out the disadvantages of a given setup, but I don't think we need to dwell on them given the the OP has already built a "phase 1" version and seems pretty aware of the drawbacks.

My input would be, with this propulsion setup be very aware of the currents you might encounter. If you get into a current that is faster than your boat's max speed, it could be a serious hazard. Even seemingly under-powered sailboats usually have a max speed under power of 6.5 knts or more.

P.S. If anyone thinks a paddle-wheel is technically complicated, I invite you to fabricate a prop from scratch. I've actually done some very basic aluminum casting in my garage, there's quite a learning curve.

[bcboomer]

Originally Posted by minaret

"Efoy fuel cartridges are real bundles of energy. They may not weight much but they are packed with energy. An M10 fuel cartridge, for example, weights only 19 pounds but contains enough fuel to produce 11.1 kilowatt hours of energy. "

80 bucks a pop!!
That has to be about the most expensive way to generate power there is.

[wildshore]

Originally Posted by wyb2

Jeez, we start with how paddle-wheels are crap, then we switched to why solar/electric is crap. Obviously props are the "right" way to drive a boat given modern tech, that's why almost all modern boat utilize it. Obviously combustible fuel is the "right" way to store energy on a boat given modern tech, that's why almost all modern boats use it.

Not all projects have to be about doing it the "right" way. If you end up with a functioning product that is fun to use and was fun to build, you've succeeded.

An all solar setup isn't about traveling fast or efficiently, it's about free fuel. Any sailor should be able to appreciate that.

Fair enough to point out the disadvantages of a given setup, but I don't think we need to dwell on them given the the OP has already built a "phase 1" version and seems pretty aware of the drawbacks.

My input would be, with this propulsion setup be very aware of the currents you might encounter. If you get into a current that is faster than your boat's max speed, it could be a serious hazard. Even seemingly under-powered sailboats usually have a max speed under power of 6.5 knts or more.

P.S. If anyone thinks a paddle-wheel is technically complicated, I invite you to fabricate a prop from scratch. I've actually done some very basic aluminum casting in my garage, there's quite a learning curve.

A) thanks for that and B) I agree about the currents issue. in the short run, we're planning on a small aux outboard in case of emergencies.

[wildshore]

Originally Posted by wyb2

P.S. If anyone thinks a paddle-wheel is technically complicated, I invite you to fabricate a prop from scratch. I've actually done some very basic aluminum casting in my garage, there's quite a learning curve.

One of the basic ideas behind the project from it's beginning is that this thing has to be buildable by just about anyone, with limited, common tools.

Floating Empire 1 used largely recycled or repurposed materials, and we've lived aboard her full time, summer and winter, for three years now. It is possible.

[captlloyd]

Originally Posted by wyb2

Jeez, we start with how paddle-wheels are crap, then we switched to why solar/electric is crap. Obviously props are the "right" way to drive a boat given modern tech, that's why almost all modern boat utilize it. Obviously combustible fuel is the "right" way to store energy on a boat given modern tech, that's why almost all modern boats use it.

Not all projects have to be about doing it the "right" way. If you end up with a functioning product that is fun to use and was fun to build, you've succeeded.

An all solar setup isn't about traveling fast or efficiently, it's about free fuel. Any sailor should be able to appreciate that.

Fair enough to point out the disadvantages of a given setup, but I don't think we need to dwell on them given the the OP has already built a "phase 1" version and seems pretty aware of the drawbacks.

My input would be, with this propulsion setup be very aware of the currents you might encounter. If you get into a current that is faster than your boat's max speed, it could be a serious hazard. Even seemingly under-powered sailboats usually have a max speed under power of 6.5 knts or more.

P.S. If anyone thinks a paddle-wheel is technically complicated, I invite you to fabricate a prop from scratch. I've actually done some very basic aluminum casting in my garage, there's quite a learning curve.

Nice post, I agree with it all. People post ideas on the CF and some responders try to reinvent the whole thing. As an example, as a fabricator,I am sure for that size hull I could fabricate the paddle-wheel assembly in 2or 3 days. What the OP is proposing would be of no interest to me, but that is me. I for one look forward to progress reports on his project. I do agree that an auxiliary power source is a very good idea.

[Stumble]

Originally Posted by wyb2

Jeez, we start with how paddle-wheels are crap, then we switched to why solar/electric is crap. Obviously props are the "right" way to drive a boat given modern tech, that's why almost all modern boat utilize it. Obviously combustible fuel is the "right" way to store energy on a boat given modern tech, that's why almost all modern boats use it.

Not all projects have to be about doing it the "right" way. If you end up with a functioning product that is fun to use and was fun to build, you've succeeded.

An all solar setup isn't about traveling fast or efficiently, it's about free fuel. Any sailor should be able to appreciate that.

Fair enough to point out the disadvantages of a given setup, but I don't think we need to dwell on them given the the OP has already built a "phase 1" version and seems pretty aware of the drawbacks.

My input would be, with this propulsion setup be very aware of the currents you might encounter. If you get into a current that is faster than your boat's max speed, it could be a serious hazard. Even seemingly under-powered sailboats usually have a max speed under power of 6.5 knts or more.

P.S. If anyone thinks a paddle-wheel is technically complicated, I invite you to fabricate a prop from scratch. I've actually done some very basic aluminum casting in my garage, there's quite a learning curve.

Wyb2,

I assume that when someone posts here and describes their project they are looking for comment or commentary. I try, though I do no that always succeed, in providing honest critical review of what I think of the project. Sadly when it comes to electrical propulsion generally my critique I see almost always negative, simply because most people have no sense of the amount of power necessary to move a vessel. This isn't a critique of them, but of the technological limitations of available hardware.

The fact remains that batteries simply do not store a meaningfully amount of power. Their energy density is simply not high enough to drive a boat at meaningful speeds or distances. It doesn't matter how much I might wish otherwise the numbers don't work.

When you start with very low energy density, then it becomes even more critical to ensure that every part of the system maximizes efficiency since you don't have any excess power waste. So here the choice to use a paddlewheel exacerbates an already serious problem and gains very little from an engineering standpoint in return.

Very shallow and weedy water can be solved by using a long tail shaft like most of the Louisiana pirogues do. Even if they are fouled you just lift the prop out, wipe of the weeds and keep running. In shallow water you just tilt them up. They are also dead simple to build, and since the engines are air cooled you don't have to worrying about water return lines or corrosion. It's a pretty simple system.


As for the OP's design. Assuming 350ah of battery power, at 12v that's 2,100kw of usable power. Enough to run a 1hp engine for about 2.5 hours at full throttle. More realistically this works out to be about 1.5kw at the prop for about 1 hour before you need to fully recharge. A 36' boat being driven by 1.5kw is going to make maybe 1kn. So figure a full charge is good for probably a mile, followed by a day or so to recharge (we haven't discussed the solar array yet). This works out to an average speed of .04knots, or about 240 feet per hour assuming no wind, waves, or current.

Assuming we are ok with this speed to estimate fuel burn for an outboard simply divide the hp needed by 15 (for a modern 4 stroke, 10 for an old two stroke). In this case the 1.5kw=2hp, 2hp/15= .133 gallons per hour. So for the same power as all of those FLA batteries we need 2.1 cups of gas. In eight hours of run time we would have used about a gallon of gas.

So a five gallon jug of gas holds about as much usable power as 40 full charges of the battery bank. Wether that takes 40 days or 20 or an afternoon is just a function of the size of the solar panel array that can be placed on the boat. The bigger and more expensive the array is the less time.

So what's our maximum array size? Well the OP mentioned 38' long, so let's assume the vessel is 12' wide giving a maximum array size of 456ft^2 or 42m^2. Solar impact on the earth is about 1kw/m^2 and solar panels are about 20% efficient and we can assume about 5 hours of solar production per day, so let's figure 42kwh/day of production.

At our assumed speed of 1kn, and a power draw of 1.5kw/hr at that speed, the boat would consume 36kwh in propulsion a day. Leaving just a little left over for house loads and inefficiency I need the system.

So how big of a battery bank do we need to harness this much power... even ignoring float charge profiles, and just limiting outselves to just the 50%SOC for FLA batteries we need the capacity to store 84kw of power or 70 * 100ah 12v FLA batteries. With a predicted weight of 7,000lbs.



All of is is still assuming the very low speeds required, and reasonable prop efficiencies. Swap to a paddlewheel, and I really have no idea. But my guess is that an articulating paddlewheel is about 80% the effiency as a screw. A fixed one I should in the 60% range.

I do not consider this a safe or reasonable useage profile. And while I appreciate the goal, and think it's a very cool project the engineering numbers don't work. If I am wrong on the numbers please show me where I made my mistake, but I don't think so. No matter how I run the number so it comes back to the same problem, batteries are not energy dense enough to provide enough power to travel meaningful distances, and solar can't put back enough to save it.

[wildshore]

Originally Posted by Stumble

Wyb2,

I assume that when someone posts here and describes their project they are looking for comment or commentary. I try, though I do no that always succeed, in providing honest critical review of what I think of the project. Sadly when it comes to electrical propulsion generally my critique I see almost always negative, simply because most people have no sense of the amount of power necessary to move a vessel. This isn't a critique of them, but of the technological limitations of available hardware.

The fact remains that batteries simply do not store a meaningfully amount of power. Their energy density is simply not high enough to drive a boat at meaningful speeds or distances. It doesn't matter how much I might wish otherwise the numbers don't work.

When you start with very low energy density, then it becomes even more critical to ensure that every part of the system maximizes efficiency since you don't have any excess power waste. So here the choice to use a paddlewheel exacerbates an already serious problem and gains very little from an engineering standpoint in return.

Very shallow and weedy water can be solved by using a long tail shaft like most of the Louisiana pirogues do. Even if they are fouled you just lift the prop out, wipe of the weeds and keep running. In shallow water you just tilt them up. They are also dead simple to build, and since the engines are air cooled you don't have to worrying about water return lines or corrosion. It's a pretty simple system.


As for the OP's design. Assuming 350ah of battery power, at 12v that's 2,100kw of usable power. Enough to run a 1hp engine for about 2.5 hours at full throttle. More realistically this works out to be about 1.5kw at the prop for about 1 hour before you need to fully recharge. A 36' boat being driven by 1.5kw is going to make maybe 1kn. So figure a full charge is good for probably a mile, followed by a day or so to recharge (we haven't discussed the solar array yet). This works out to an average speed of .04knots, or about 240 feet per hour assuming no wind, waves, or current.

Assuming we are ok with this speed to estimate fuel burn for an outboard simply divide the hp needed by 15 (for a modern 4 stroke, 10 for an old two stroke). In this case the 1.5kw=2hp, 2hp/15= .133 gallons per hour. So for the same power as all of those FLA batteries we need 2.1 cups of gas. In eight hours of run time we would have used about a gallon of gas.

So a five gallon jug of gas holds about as much usable power as 40 full charges of the battery bank. Wether that takes 40 days or 20 or an afternoon is just a function of the size of the solar panel array that can be placed on the boat. The bigger and more expensive the array is the less time.

So what's our maximum array size? Well the OP mentioned 38' long, so let's assume the vessel is 12' wide giving a maximum array size of 456ft^2 or 42m^2. Solar impact on the earth is about 1kw/m^2 and solar panels are about 20% efficient and we can assume about 5 hours of solar production per day, so let's figure 42kwh/day of production.

At our assumed speed of 1kn, and a power draw of 1.5kw/hr at that speed, the boat would consume 36kwh in propulsion a day. Leaving just a little left over for house loads and inefficiency I need the system.

So how big of a battery bank do we need to harness this much power... even ignoring float charge profiles, and just limiting outselves to just the 50%SOC for FLA batteries we need the capacity to store 84kw of power or 70 * 100ah 12v FLA batteries. With a predicted weight of 7,000lbs.



All of is is still assuming the very low speeds required, and reasonable prop efficiencies. Swap to a paddlewheel, and I really have no idea. But my guess is that an articulating paddlewheel is about 80% the effiency as a screw. A fixed one I should in the 60% range.

I do not consider this a safe or reasonable useage profile. And while I appreciate the goal, and think it's a very cool project the engineering numbers don't work. If I am wrong on the numbers please show me where I made my mistake, but I don't think so. No matter how I run the number so it comes back to the same problem, batteries are not energy dense enough to provide enough power to travel meaningful distances, and solar can't put back enough to save it.

Greg, thank you for your input.
We are building a paddlewheel boat as we like their performance, especially at low speed and with high torque motors, the simplicity of construction, and the way they suite what we want to do with the vessel.
I disagree with you regarding the energy density of batteries, and I think Elon Musk would as well. The intial project will use glass mat cells, with lithiums in the future as soon as the rest of the system gets up and running.
The motor will likely be running at 48V or higher off 800AH of battery with a minimum of 600 watts of solar panels.

The boat we are building is not 36', it's 20', and extremely light on the water, and this is an experiment to see what we can make work.

We are not burning any fossil fuels because we're tree huggers, do not own cars, and are doing everything in our power to keep every ounce of the wretched stuff in the ground.

Don

[sammyo]

Set it up with a notch for a long sculling oar in the stern with a spot to stand and with practice you'll probably make better speed than a paddle.

[wyb2]

For the most part, I actually think you are right. I think you made a couple of assumptions that make the picture look a little bleaker than it is.

Originally Posted by Stumble

Wyb2,

I assume that when someone posts here and describes their project they are looking for comment or commentary. I try, though I do no that always succeed, in providing honest critical review of what I think of the project. Sadly when it comes to electrical propulsion generally my critique I see almost always negative, simply because most people have no sense of the amount of power necessary to move a vessel. This isn't a critique of them, but of the technological limitations of available hardware.

Fair statement

The fact remains that batteries simply do not store a meaningfully amount of power. Their energy density is simply not high enough to drive a boat at meaningful speeds or distances. It doesn't matter how much I might wish otherwise the numbers don't work.

I would caveat that with "lead-acid" batteries. Different chemistries have been dramatically improving battery energy density over the past few decades, however they all cost more money. There's a reason a Tesla can go 300 mi on a Li-Ion battery pack, and a reason it costs $90K.

When you start with very low energy density, then it becomes even more critical to ensure that every part of the system maximizes efficiency since you don't have any excess power waste. So here the choice to use a paddlewheel exacerbates an already serious problem and gains very little from an engineering standpoint in return.

Agree

Very shallow and weedy water can be solved by using a long tail shaft like most of the Louisiana pirogues do. Even if they are fouled you just lift the prop out, wipe of the weeds and keep running. In shallow water you just tilt them up. They are also dead simple to build, and since the engines are air cooled you don't have to worrying about water return lines or corrosion. It's a pretty simple system.

Sounds like one way to solve the problem.

As for the OP's design. Assuming 350ah of battery power, at 12v that's 2,100kw of usable power. Enough to run a 1hp engine for about 2.5 hours at full throttle. More realistically this works out to be about 1.5kw at the prop for about 1 hour before you need to fully recharge. A 36' boat being driven by 1.5kw is going to make maybe 1kn. So figure a full charge is good for probably a mile, followed by a day or so to recharge (we haven't discussed the solar array yet). This works out to an average speed of .04knots, or about 240 feet per hour assuming no wind, waves, or current.

Well 350 ah of capacity is an assumption, the OP was thinking 400-800. All I would say here is that rated shaft power on an outboard does not equal propulsive power. Toqeedo gets away with recommending about 1/2 the power of an "equivalent" 4 stroke outboard. Of course this is a prop-to-prop comparison, as you say later the paddle-wheel adds another layer here, and not in a good way.

Also that 2hp (1.5kw) makes 1knt is an assumption, maybe it's correct, I don't know. But would 2knts be possible? Change that assumption and go to 800 ah of capacity, and now we are looking at 4-5 miles on a charge with no incoming solar. Not how I would want to travel, but now it seems possible.

Assuming we are ok with this speed to estimate fuel burn for an outboard simply divide the hp needed by 15 (for a modern 4 stroke, 10 for an old two stroke). In this case the 1.5kw=2hp, 2hp/15= .133 gallons per hour. So for the same power as all of those FLA batteries we need 2.1 cups of gas. In eight hours of run time we would have used about a gallon of gas.

Sure, gas is definitely more energy dense.

So a five gallon jug of gas holds about as much usable power as 40 full charges of the battery bank. Wether that takes 40 days or 20 or an afternoon is just a function of the size of the solar panel array that can be placed on the boat. The bigger and more expensive the array is the less time.

So what's our maximum array size? Well the OP mentioned 38' long, so let's assume the vessel is 12' wide giving a maximum array size of 456ft^2 or 42m^2. Solar impact on the earth is about 1kw/m^2 and solar panels are about 20% efficient and we can assume about 5 hours of solar production per day, so let's figure 42kwh/day of production.

yeah and that is using every square inch of the boat, likely reality is significantly less.

At our assumed speed of 1kn, and a power draw of 1.5kw/hr at that speed, the boat would consume 36kwh in propulsion a day. Leaving just a little left over for house loads and inefficiency I need the system.

This assumes traveling 24hrs straight, quite a change from the 1 hr limit earlier. If you change the assumption to say, making a max of 5 hr hops, your requirement has just dropped to 7.5 Kwh/day. Intended use makes a huge difference. Don't get me wrong, this is still a lot for lead-acid batteries (625 ah/day at 12v), but all of a sudden we are in the realm of possibility (if not practicality).

So how big of a battery bank do we need to harness this much power... even ignoring float charge profiles, and just limiting outselves to just the 50%SOC for FLA batteries we need the capacity to store 84kw of power or 70 * 100ah 12v FLA batteries. With a predicted weight of 7,000lbs.

Using my change from above this is 13 x 100ah 12v batteries, so 1,300 lbs @ 100lbs each (or 900 lbs @ 70 lbs each, which is the shipping weight on amazon). Again - practical? Not really. Possible? I think so.

All of is is still assuming the very low speeds required, and reasonable prop efficiencies. Swap to a paddlewheel, and I really have no idea. But my guess is that an articulating paddlewheel is about 80% the effiency as a screw. A fixed one I should in the 60% range.

If 60% is correct, that would just about cancel out my gas-to-electric-based-on-Torqeedo-marketing factor from above, so maybe back to comparing them 1 to 1.

I do not consider this a safe or reasonable useage profile. And while I appreciate the goal, and think it's a very cool project the engineering numbers don't work. If I am wrong on the numbers please show me where I made my mistake, but I don't think so. No matter how I run the number so it comes back to the same problem, batteries are not energy dense enough to provide enough power to travel meaningful distances, and solar can't put back enough to save it.

So no, I don't think you're numbers are wrong, just that changing some of your (reasonable) assumptions to my (I hope also reasonable) assumptions changes the outlook to "possible".

Of course feel free to point out any issues with what I've said. I may or may not respond, I actually really enjoy this sort of thought experiment, but at the end of the day internet debates can eat up way too much time.