Electric Houseboat concept

[Finnigan]

We live on a all electric Morgan O/I33 (almost 4 years now) Although we are in the bay and not on a river with the current always going in the same direction we do get some good flood and ebb action It has been my experience that it takes a lot more power to get moving than it dose to keep moving. The Morgan is 16000 lbs and cruises very happy on average 4-4.5kts @ 35-37 amps @48vdc + or - 1kt for the currant. I would think that a 12000 lb house boat with 2 10-12kw inboards should have no trouble slipping along @ 5-6 kts for several hours depending on the battery bank. Power storage and charging are the main challenges I went old school and use lead acid 300ah @ 48 volts and am good for 35-40 miles on a charge. There are a lot of opinions about why it wont work but we are very happy with electric. If you are handy with tools and shop wisely you can build a nice 10kw system with flooded LA batteries for about
$6-7k each LI batteries will turn that into $17000 reel fast. Also solar to charge them aint gona be cheap 24 100watt panels That's why We use shore power and a gen set It takes the little Honda all evening and some times longer to charge it back up Good luck if you take the challenge
SV Finnigan SF Bay

[StuM]

Originally Posted by Finnigan

The Morgan is 16000 lbs and cruises very happy on average 4-4.5kts @ 35-37 amps @48vdc + or - 1kt for the currant.
...
use lead acid 300ah @ 48 volts and am good for 35-40 miles on a charge.

Sorry, but your figures don't make sense.

300Ah Lead acid - so good for maybe 150Ah if you want them to last.

35-37 Amps means that 150 Ah is good for about 4 hours.

4 hours @ 4-4.5 knots = 16 - 18 nm. Where does your 35-40 come from?

If you try to get 35-40 miles out of that battery bank, you would flatten it completely. A few cycles like that and the batteries would be dead.

[Stumble]

Originally Posted by StuM

Sorry, but your figures don't make sense.

300Ah Lead acid - so good for maybe 150Ah if you want them to last.

35-37 Amps means that 150 Ah is good for about 4 hours.

4 hours @ 4-4.5 knots = 16 - 18 nm. Where does your 35-40 come from?

If you try to get 35-40 miles out of that battery bank, you would flatten it completely. A few cycles like that and the batteries would be dead.

I could believe that range, you just have to slow down to about 2kn. A good rule of thumb is if you double the speed you need four times the power (so long as you are still below 1.34S/L).

The problem of course is that motoring at 2kn it will now take all day to do what should have been a 3 hour trip.

[Fishman_Tx]

Part 1

Originally Posted by alctel

Can't remember the name for the life of me but someone did exactly that - pulled off mast and rigging and installed a 'roof' of solar panel and an electric engine. Seemed to work out ok!

I thought about that! Plenty of dismasted junkers left over from Ike around here I could get cheap, if not free!

Originally Posted by StuM

Finally an electrically propelled vessel idea that has a reasonable use case!

Go for it!

(As long as you can afford the $100,000 or so that it will cost to get a workable system up and running)

Naah, don't think it'll get that expensive. I'm figuring $20-30k at most for the system to start. That's the reason I'll be using other than "marine" to get the price back into a reasonable range. Want to keep the total package at under $45k on initial installation and add extra panels and cells as I go. Maybe try to work my way toward fuel-less. Hell, at least get the basics. I got 4 years to do it before I retire and bail out. Plenty of older 40' barges for $15k+ out there and who says you gotta pay the asking price? Interior work I'll do myself. As long as it's structurally sound, remodeling the interior is no different than a house or trailer. Home Depot cabinetry, etc..

Originally Posted by a64pilot

In my opinion, you want to find an honest house boat, big boxy barge looking thing that has a flat roof the size of the boat, roof usually used as the place to grill out, big porch kind of thing but will provide huge Solar space. It's Solar capacity that in my opinion that will be the limiting factor, assuming you can live with mostly floating down a river using motor for steerage more than anything else, I think you could make it work. Forget wind, too expensive and not much wind where you will be anyway.
But as has been said, the gotcha is its gonna cost at least ten times what two 20 Hp or so outboards will, have less range, will be a Science experiment with that kind of reliability etc.
10 KW of Solar will cost more than $10,000 I think and we haven't stored that power yet, maybe 5K or so for batteries?
Run maybe every third day or so?

Forget electric outboards in my opinion as well, maybe you can get a couple of golf cart motors to work depending on vessel size, but forget automobile electric drive, Prius for example is actually I believe electronically controlled AC motors, being driven with about 300 VDC or so. I'm not sure about that, point is it's pretty technical and may not lend itself so well to being hacked, and that high a voltage and huge amperage has to be playing with fire.

Be foolish not to have a back up generator, but if it's big enough to drive the boat, then it will be less efficient than a lighter boat with direct engine drive would be, so I would think 3KW or so to run air conditioners and house loads but not drive the boat.

Exactly! Whichever hull provides the least drag and the best efficiency of propulsion. I'm specifically looking at single level, preferably without flybridge. The sundeck or overhead will be covered in panels, each NO LESS THAN 420w x 49vdc VMPP. I'm currently looking at the moment at AC-34 motors at Thunderstruck-ev.com for $3200 but not much for specs there.

Originally Posted by StuM

I'd budget about 10 times that for a big bank of Lithium batteries that can handle the 800 or so Amps your 10kW of solar can put out.. They make a lot of sense in this application.

Initially, lithiums are going to be too expensive, but would like to migrate that direction for the power the can provide.

Originally Posted by tkeithlu

Let's just conclude that you should do a lot of calculating and a lot of comparing costs before you invest money in this idea rather than in an outboard engine. That's much nicer than "What the hell were you thinking?", and we should all have dreams.

Oh, I'll be researching for a year minimum before I spend a dime, probably two. Hell, maybe more!

Originally Posted by Stumble

You do electrical work...

2 X 10kw motors X 8 hours = 160kwh that's your draw
8 X 420w X 6hours = 20.16kwh is your production

So basically for every day you spend on the hook not using any power with perfect solar capture you can motor one hour. Even at 10kn which is unlikely for a boat this size, you are still averaging 10 miles a day, less in current.

The reality is that solar simply doesn't provide enough power for propulsion. If you want to go this route then you need to start seriously looking at a large diesel generator to drive the electrical engines for anything more than in and out of a marina.

Bigger or heavier battery banks allow you to run longer when you do run, but also force you to dedicate more volume and weight to battery storage. It's a downward spiral.

Yeah but there are more than 6 daylight hours in a day and the bell ends of the curve must also be considered, say 30% avg per side of the mark. That's also why the backup genset. If I need to motor travel, then the gen can augment the solar to keep up with the draw. The goal is to become fuel-less eventually, but I don't see that as initially feasible.

Originally Posted by Stumble

Down river it would probably work fine, but going back up... Keep in mind that the Mississippi averages about 3kn, and routinely has a 5kn current. To make any headway your going to need to be able to maintain 6-8kn. That's a lot of power to provide from just solar panels.

Obviously it depends on the batteries and panels, but figure you could expect to operate 8 hours every 3-4 days. Assuming you can hit 6kn that means you are going to average 6 miles a day...

Originally Posted by valhalla360

I suspect, your 7kt cruise with 20hp, is a little optimistic for an inefficient houseboat hull. Scale that back to 5-6kts and it's probably doable but 6kts would likely be running full throttle.

As others have said the solar/battery power is just not enough to do anything meaningful. Plan on being a diesel/electric boat. Particularly if you want to wander the Mississippi, you need decent power and the ability to supply it continuously. 7kts won't get you up the Mississippi.

You apparently have the technical knowhow, so start running the numbers for power generated and power consumed. I think you will find it works fine (all be it more expensive) on some of the slower waterways but when you get to the waterways with faster currents and longer distances between stopping points, it will become a problem.

The rivers will be only a means to a destination. The highway from A to B. 10kts is what I want as a max capability at dead calm so that I can make at least a couple of knots in strong current going uphill. Of course, I have no intention of river runs at high flow times. Hell, the tugs are a misery in spring. Saw one literally pushed over and under a bridge in strong current AFTER he had already cut the tow loose. My Dad gave me a lot of knowledge on what NOT to do on the rivers and WHEN not to do it.

Originally Posted by Dockhead

I think you've gotten an excellent set of answers to your question! Running the numbers is the key.

If you're doing it for fun and for an engineering challenge, and have money to burn, go for it! I agree with Stu that this is the ideal application for such a system with large roof area and relatively small power requirement.

If cost is a factor, though -- run the numbers, do a budget, and you'll see that it will cost you probably 20x what a simple gasoline outboard would, and this will never ever pay for itself in fuel savings, not even in 100 years. And you will need the fossil fuel anyway because you won't get enough power from solar for all your propulsion.

You could go diesel-electric as someone suggested, but the big generator would be expensive and would be massive overkill for your other needs.

If you just wanted to play around with the technology, the most practical approach might be to have your gasoline outboard, but with a parallel electric drive with a more reasonable battery bank. You might cover a fair amount of your propulsion with the electric drive but need not design it to cover all of it, since you have the outboard. This will be much cheaper and more practical, and the economics would be better since you will probably save a fair amount of fuel, and get that with far smaller investment.

Also a large solar installation will definitely cover all your domestic power needs, and that is great and what existing solar technology already does well and economically.

10-15kw diesel outta do it. I have a 60 but I doubt it would fit. LOL!!

Originally Posted by Steady Hand

I agree with all of Dockhead's post above.
The large surface area of a typical houseboat roof would be a great "solar farm" for domestic needs, and a dependable and economical gas outboard would be good for those days when going is important.

I looked at the MOGU boat site, and while that boat looks appealing as a concept for a still water (no waves, few wakes) river (like some of the springs in Florida), I don't think the powering or range ability is appealing, as it seems more designed for short hops and on very mild waterways.

Pretty much what I'm after. I don't on making too many long one-shot trips. Just gunkholing along until I find a nice spot to spend a week, month, year... The best for me are small river backwaters, national forest frontages, canals, coves, slews, etc. Where ever people AREN'T. Hell, I'm really considering the Atchafalaya in Louisiana. Tons of square miles to get lost in.

Originally Posted by ranger42c

I'd like to see you get there from here. Given your probable freedom to "stay put" until weather and/or available stored electrical power are acceptable, I'd think you might be able to... or at least come close enough for your own comfort level.

A backup genset for electricity seems appropriate. A backup propulsion motor for emergency movements or heavy weather seems appropriate.

OTOH, both of those come with a requirement to store fossil fuel, in some TBD quantity. Given that requirement exists too...

Just seems reasonable to suggest you spec out your best solar/wind system -- maybe include something underwater that uses river current to generate electricity too (sort of like automotive regeneration -- and then once you have those specs all costed out... including the cost of that backup genset, that backup propulsion, and whatever fossil fuel tankage...

Compare all that to the cost of a genset, two (probably) appropriately-sized outboards (or maybe a single, that's just bigger altogether than the idea of an emergency thing), and (maybe larger) fossil fuel storage.

If you're satisfied with the cost comparisons, E Voila!

Wouldn't surprise me if the genset/outboard(s)/decent tankage comes in less expensive, but that's just a WAG.

But it also wouldn't surprise me to learn that a genset, 2 outboards, tankage -- and a big, honkin' solar farm, too, with appropriately-sized battery storage -- could in the end be relatively inexpensive living.

In that approach, you could probably grow the system incrementally: add more solar when you can, add more battery when you can, add a wind generator when you feel like dealing with the noise, etc etc etc.

Eleven guitars should be easy. I'd have to deal with drum kits, a keyboard, a baby grand, PA, too...

The outboard will probably be a single 130+ hp with external tankage, though I really don't want to keep gasoline on the boat. I'd rather keep it all diesel. The power system will definitely be overkill while static, but just think...I'll never be running the genny!

[Fishman_Tx]

Part 2

Originally Posted by Finnigan

We live on a all electric Morgan O/I33 (almost 4 years now) Although we are in the bay and not on a river with the current always going in the same direction we do get some good flood and ebb action It has been my experience that it takes a lot more power to get moving than it dose to keep moving. The Morgan is 16000 lbs and cruises very happy on average 4-4.5kts @ 35-37 amps @48vdc + or - 1kt for the currant. I would think that a 12000 lb house boat with 2 10-12kw inboards should have no trouble slipping along @ 5-6 kts for several hours depending on the battery bank. Power storage and charging are the main challenges I went old school and use lead acid 300ah @ 48 volts and am good for 35-40 miles on a charge. There are a lot of opinions about why it wont work but we are very happy with electric. If you are handy with tools and shop wisely you can build a nice 10kw system with flooded LA batteries for about
$6-7k each LI batteries will turn that into $17000 reel fast. Also solar to charge them aint gona be cheap 24 100watt panels That's why We use shore power and a gen set It takes the little Honda all evening and some times longer to charge it back up Good luck if you take the challenge
SV Finnigan SF Bay

Would you mind giving me some specs on your system? Here or PM. I'll take all the ideas I can get!

Originally Posted by StuM

Sorry, but your figures don't make sense.

300Ah Lead acid - so good for maybe 150Ah if you want them to last.

35-37 Amps means that 150 Ah is good for about 4 hours.

4 hours @ 4-4.5 knots = 16 - 18 nm. Where does your 35-40 come from?

If you try to get 35-40 miles out of that battery bank, you would flatten it completely. A few cycles like that and the batteries would be dead.

True that! Don't want to use any more than 40% but a good smart controller will warn you when you get to your mark.

Originally Posted by Stumble

I could believe that range, you just have to slow down to about 2kn. A good rule of thumb is if you double the speed you need four times the power (so long as you are still below 1.34S/L).

The problem of course is that motoring at 2kn it will now take all day to do what should have been a 3 hour trip.

And that's the rub. Getting the right balance of power output/speed vs. power input and the capability of the hardware within a doable price range.

[Fishman_Tx]

For example. Nice candidates...
1979 Kayot Houseboat - 42' Houseboat for Sale in Greenehaven, Arizona

http://www.everyboat.com/boat/3685-1...boats-islander

[Finnigan]

Dont want to miss lead anyone that is interested in EP systems but just relaying personal experience
Last weekend we went out and had to motor the whole trip we did 40.48 miles 34.5 nm @an average of 4.2kts I will admit that I was pushing my luck using 270ah of the 310 that we left the dock with average draw was 33amps. I wouldn't suggest such a stunt until you are very familiar with the system
Our batteries are 3 years old and the maker (US Battery) states 700 cycles to 80% DOD Trojan states 1500 cycles @80% DOD if I was rich I would like some Rolls
They are industrial deep cycle scrubber batteries and not Cost Co or Sams Club GC2s still running them down to 14% is probably not leaving much room for error I have the low batt warning light set @ 80% DOD
Good purpose built flooded batteries are a lot tougher than they get credit for but you do have to take care of them not drop them in the bilge and forget about the till there is a problem (monthly watering equalizing cleaning and checking all connections) LI would provide more cycles (they say 2000) with less weight but @ 5-6X the cost
I will say that when I was tearing out the Perkins everyone ask what are you doing and that wont work now they ask if we are going out this weekend and if I don't have to work I get to say yes
SV Finnigan

[StuM]

Originally Posted by Stumble

I could believe that range, you just have to slow down to about 2kn. A good rule of thumb is if you double the speed you need four times the power (so long as you are still below 1.34S/L).

The problem of course is that motoring at 2kn it will now take all day to do what should have been a 3 hour trip.

All day and most of the night

But if he can keep a 16000lb O/I33 making 2 knots on 7 Amps @48V (336W or less than 0.5HP), he's doing very well. Even Torqeedo don't claim that sort of performance

[StuM]

Originally Posted by Fishman_Tx

Yeah but there are more than 6 daylight hours in a day and the bell ends of the curve must also be considered, say 30% avg per side of the mark.

We see exactly this comment all the time from people who are not actually using solar and are dreaming about a "free energy life".

They always forget than in the peak hours, they are very rarely going to get anywhere near 100% of the theoretical output. So the 5-6 hours used in the calculation is a simplified figure which averages out the factors of sun angle, hours of sunlight, cloudiness etc over a full day.

In other words, the bell ends of the the curve are already included in that figure.

Even if you have 14 hours of daylight, you will still only get about 5-6kWh per day out of 1kW of panels at best.

Those of us who rely on solar are well aware of this in practice.

[StuM]

Originally Posted by Finnigan

Dont want to miss lead anyone that is interested in EP systems but just relaying personal experience
Last weekend we went out and had to motor the whole trip we did 40.48 miles 34.5 nm @an average of 4.2kts I will admit that I was pushing my luck using 270ah of the 310 that we left the dock with average draw was 33amps. I wouldn't suggest such a stunt until you are very familiar with the system

I assume that your "310"Ah capacity is the rated capacity which would be at C20. You were discharging them at above C10, which means they probably were only capable of producing about 290Ah or less in that scenario.

IOW, you almost certainly ran you batteries down to less than 10% SOC and had very little reserve. They are not going to last much longer if you keep doing that

[ranger58sb]

Originally Posted by Fishman_Tx

The outboard will probably be a single 130+ hp with external tankage, though I really don't want to keep gasoline on the boat. I'd rather keep it all diesel. The power system will definitely be overkill while static, but just think...I'll never be running the genny!

I dunno if that would be a benefit around here; most of our Summer, AC is sorta mandatory, and I've read ACs aren't gonna work from batteries (solar, inverters, whatever). If true, genset would be important...

That does bring up another thought, though. Consider costing out a small diesel, maybe with jackshaft to an outdrive or some such... to compare against the 130-hp gas outboard option... and to see about how it all might work with diesel auxiliary propulsion and a diesel genset. That would at least maybe address the gasoline-on-board issue. Then compare all that cost do your electrical set-up plans, too.

-Chris

[ranger58sb]

Originally Posted by ranger42c

That does bring up another thought, though. Consider costing out a small diesel, maybe with jackshaft to an outdrive or some such... to compare against the 130-hp gas outboard option... and to see about how it all might work with diesel auxiliary propulsion and a diesel genset. That would at least maybe address the gasoline-on-board issue. Then compare all that cost do your electrical set-up plans, too.

I forgot to peck out Part II of that idea...

I think ZF or somebody like that (and likely others) make electric-driven azipod drives... sorta like an outdrive under the boat... or like an electrically driven version of the Volvo/IPS or Cummin/Zeus pod drives.

Maybe consider doing the math on something like that, driven from a genset when necessary (as when you don't have enough stored in batteries, or when weather or sea states dictate). Or maybe two gensets, maybe both of equal size, or maybe one larger than the other.

-Chris

[valhalla360]

Originally Posted by Fishman_Tx

Naah, don't think it'll get that expensive. I'm figuring $20-30k at most for the system to start. That's the reason I'll be using other than "marine" to get the price back into a reasonable range. Want to keep the total package at under $45k on initial installation and add extra panels and cells as I go. Maybe try to work my way toward fuel-less. Hell, at least get the basics. I got 4 years to do it before I retire and bail out. Plenty of older 40' barges for $15k+ out there and who says you gotta pay the asking price? Interior work I'll do myself. As long as it's structurally sound, remodeling the interior is no different than a house or trailer. Home Depot cabinetry, etc..

For $45k you can have a fully functional houseboat that will have a resale value. By the time you do your conversion and add the extra panels, you probably have covered several years worth of fuel.


Exactly! Whichever hull provides the least drag and the best efficiency of propulsion. I'm specifically looking at single level, preferably without flybridge. The sundeck or overhead will be covered in panels, each NO LESS THAN 420w x 49vdc VMPP. I'm currently looking at the moment at AC-34 motors at Thunderstruck-ev.com for $3200 but not much for specs there.

If you want efficiency, you don't want a houseboat hull, particularly if you want to go above 4-5kts.


Yeah but there are more than 6 daylight hours in a day and the bell ends of the curve must also be considered, say 30% avg per side of the mark. That's also why the backup genset. If I need to motor travel, then the gen can augment the solar to keep up with the draw. The goal is to become fuel-less eventually, but I don't see that as initially feasible.

6hrs is already including the tails of the curve.

The rivers will be only a means to a destination. The highway from A to B. 10kts is what I want as a max capability at dead calm so that I can make at least a couple of knots in strong current going uphill. Of course, I have no intention of river runs at high flow times. Hell, the tugs are a misery in spring. Saw one literally pushed over and under a bridge in strong current AFTER he had already cut the tow loose. My Dad gave me a lot of knowledge on what NOT to do on the rivers and WHEN not to do it.

A pair of 10kw engines, isn't going to give you anything close to 10kts. You are probably looking at 10 times that amount of power.

The rivers have currents year round. A slow times, the Mississippi can run 3-4kts. If the pair of 10kw engines optimistically gets you 6kts, you run into the problem of "can you make the next anchorage during daylight?"



10-15kw diesel outta do it. I have a 60 but I doubt it would fit. LOL!!

The 60 would be marginal to get any kind of speed.

Pretty much what I'm after. I don't on making too many long one-shot trips. Just gunkholing along until I find a nice spot to spend a week, month, year... The best for me are small river backwaters, national forest frontages, canals, coves, slews, etc. Where ever people AREN'T. Hell, I'm really considering the Atchafalaya in Louisiana. Tons of square miles to get lost in.


Once you are there, it's fine but getting from one area to the next is where you will run into problems.

The outboard will probably be a single 130+ hp with external tankage, though I really don't want to keep gasoline on the boat. I'd rather keep it all diesel. The power system will definitely be overkill while static, but just think...I'll never be running the genny!

Once you pay for the outboard, $45k for the electric system could buy a genny and run it for decades.

If this is just a project to show it can be done, have fun but if you think you will be saving anything in the end, you are going to be disappointed.

[Fishman_Tx]

Thanks guys!

..but one last time...
The point of this whole op is to go fuel free as much as possible. Everything can be run off DC, so lets not argue feasibility as that point has already been proven and is moot. This is about a retired liveaboard with not much money to live on after the fact and needs to be as free as possible from extra expense, specifically and especially fuel. I'll move as I feel the need to move within the bounds of the system installed or adjusted as it is upgraded. This IS NOT an engineering exercise, it is a means to an end and I will make do with what I can afford within the specification.

Now how about some ideas and constructive commentary?


Ranger
Re: diesel outboard: if I could find one reasonably priced, it's what I'd prefer. No gas on the boat if i can help it.
On outdrives: any form of electric drive is to be considered as long as it can replace a minimum of 40hp diesel.


StuM
Re: bell curve. Ok I see that. I only assume 50% of actual rating at best from get-go. Anything above that is a bonus. At AT&T we engineer everything to 50% and upgrade at 85% capacity. This allows for system load growth and for surge loads so that we can get 15-20 years out of a genset or DC plant installation instead of outgrowing it in 5-8 years. Yes, we have outgrown too soon and all too often as the company pinches pennies harder and harder and goes cheap on equipment.



Now the next question:
Which is the most efficient hull vs propulsion hp and why?
1. flat barge bottom
2. shallow v
3. deep v
4. shaped nosed pontoon

[Stumble]

You have competing needs. The most efficient hull shape is a long narrow hull. Basically a sailboat hull that has been stretched. Ideally it would have a l/b in excess of 15/1. The ll shapes you mention are all planning or semi-planning hulls and are horrifically inefficient at displacement speeds. The exception being a flat barge, but it is just as bad in different ways, it pushed a wall of water in front of it. Probably the best from an efficiency standpoint is the pontoons, but they have minimal load carrying capability and are fragile. Not what I would want to live on at all.

Assuming a big battery bank, and thus the weight, your only good option is to go with a sailboat hull, cut off the keel, they layer the batteries in the bilge.


I seriously don't understand this project however. If you are concerned about the cost of fuel, you will never pay back the conversion cost to electric. If you just took the cost of doing the conversion and put it into AAA bonds you would make enough in interest to cover the fuel bill on a diesel. By the time you count in the battery replacement costs every 8-10 years you will be far ahead.

But assuming this is the plan, all engineering and financial reality aside.... Buy mid weight sailboat hull that is the longest and skinniest you can find. Rip everything but the structural bulkheads out, cut off the keel, and start adding back batteries until you get close to the loaded max displacement of the hull. Then build a frame over the entire boat for solar panels.

This will give you the maximum possible range. With a top speed dependent on length, but assuming a 40' boat, around 8kn with a 30kw motor.