Solar Powered Canoe

I have been lurking around here for a bit and this is my first project.

I had a 14' old town canoe with an old refurbished Minn Kota 36lbs trolling motor, and a worn out battery that I got on CL several years ago for dirt cheap.

Now I have made several upgrades:
Minn Kota Endura Max 40 (with the built-in digital PWM controller)
55amp hour deep cycle sealed battery
300 Watt solar panel
MPPT charge controller
Cheap Chinese watt/amp/volt meter between the battery and motor
upgraded APC 12X8P prop
40 amp DC breaker

I have taken it to the water twice now and I am impressed with the results as timed over a 1,000 foot course:
At 100 watts I can hold 2.8mph, 200 watts will get me 3.9mph, 300 watts 4.2, and if I open the throttle wide open with the APC prop, I pull 475 watts and can max out at 4.6mph. (The original minn kota prop would max at 320 watts at 3.7mph) Looks like I may be up against my hull speed over 4.5 mph. The hull speed estimation of 1.34xsqrt(14') is around 5 knots, however my canoe is quite wide and banged up so I expect a little less.

The panel/mppt combination is doing great as well. I have only been out in the mid to late mornings, (Texas is a bit hot in the afternoon) but I am still reading 240 watts around 11 am from a flat orientation. Even the occasional cloud only drops to around 80-100 watts, which is still good for 2.8mph from above.

I spent several hours on the water, and the power gauge read 60+ amp hours consumed, while my battery was still above 12 volts by the time I got out of the water. So the 300 watt panel is working as intended, the MPPT is doing a great job and if I keep the load and supply power balanced my battery doesn't draw at all! The only weak link is the Chinese power meter. It was rated for 100amps, but only has 12 gauge wire. Over 300 watts, those get quite hot. Are Chinese amps different? :wink:

Next up I plan to make a run down the Brazos river from Whitney dam to Waco in one day. It is 36 miles, and usually an overnight trip, however with plenty of sun and a constant 4-5 mph with current, I should make it home with plenty of time to spare.

Next steps:
I am trying to get javaprop to work for me to refine the prop selection. So far I can not get the downloaded app or in browser to play nice. In the mean time if someone wants to run the numbers for me and help me select the closest OTS APC prop, well that would be great: I would like to get the maximum speed/efficiency for 300 watts with my stock motor.

Much later after I learn all the basics, I am going to work on reducing weight, and increasing speed, cut the battery size, custom build a lighter panel, work on system efficiency, a more slippery boat, etc...

Also is there a solution for regulating motor power to keep the battery above a safe voltage? For example, if the panel is producing 100watts, and the motor is drawing 300 watts, I would like a system to cut back on the power to 100 watts once the battery hits 50% SOC. I have no idea what that system would look like or even how to Google such a device. I have looked all over the forums but have not found an answer. Right now I must monitor power production, power consumption, and a battery voltage that is being buffeted by being pulled from and charged at the same time. HA.

Thanks!
EBAO

Video Link
http://youtu.be/IpBpYCHk3P0?list=UUDFA9vJBF5bMErgXiLAbXCg

Impressive little setup..

Sounds to me that your "sweet spot" is 2.8 mph at 100watts consumption.

IAN

Yea pretty sweet man I am impressed. I have a few canoes my old town is a 169.

I used to power a flat back coleman years ago , but anymore I just paddle. Creeks here are a bit smaller.

I am waiting for some type of pole mounted motor electric of course that's not so obvious or heavy but not holding my breath either.

Anyway love what you have going on that's choice.

The easiest recommendation I can give for prop size is just to buy a couple ( considering their low cost ) of different sizes and try them out.
The 12x8 is obviously too big, ( I wouldn't use anything that draws more watts than the stock prop ) and I would also stick to sizes where the pitch is about 2/3rds of diameter just like your 12x8 is.

Either 11x7 and 10x6 or 10x7 are likely going to be the winners.


Please keep us updated on your progress, this is an interesting thread.

Dean

That's a nice project.
I think the little wattmeters for R/C are not made for continuous use. Here in the UK I am using a Neodym wattmeter (currently available from Modelmaniacs) to control a brushless outboard conversion; the spec says 75A continuous, 100A burst. It even has a built in servo tester and I use this to control the ESC. Doesn't look or feel like quality but it has worked for me and doesn't seem to get hot.
Do you have a problem with weeds in your river?

Yes I plan to try out a few different size props, I have a few on order.

My little chinese watt meter just reads current, does not control the motor. I will look into yours.

The Brazos does not have a lot of weeds, just reeds and a little moss. I can give a burst in reverse to clear prop. My biggest concern is the occational submerged log. Hitting one of those going 4mph is scary, part of the reason my motor is on a hinge now.

Hopefully I can take it back out soon, maybe next week.

Looks like fun except having the summer sun beating down on you. Unless you're fishing where it would get in the way. I'd find a way to get that solar panel giving me shade despite being more unruly in the wind, even if it meant adding some more panel area to offset the extra aero drag, and pontoons that don't touch the water until it lists over enough....Maybe hinged legs to be able to lower it forward like you have it now.

To crudely solve the issue of wanting to run lower power when the solar output is lower, simply install a bypass and run straight off the panels only unless you lose sun.

Do you know what kind of throttle signal is sent to the internal motor controller? I ask because you may be able to get a Cycle Analyst to do exactly what you want. Connect the panel output between the motor and battery, and then the CA's shunt would go between the battery and the solar panel connection to measure the net energy out of the battery. With the battery capacity set in the CA, it has the ability to cut power back to a desired level when the battery reaches the DOD you choose.

EBAO, just saw your post and pic. I checked out your video on U Tube, heck I watched it 4 times

I found this site by doing a Google Search for 'solar powered canoe'

I've messed around with solar boats for a few years and am almost done with my 3rd. I'd like to tell you about it if I may. I don't mean to hijack your thread so I'll post a link to a Yahoo Group I started for solar powered boats. Mine is Only Solar but most of the members use the solar in conjunction with a battery.

Hope you and all interested check it out. I'm going to look at the rest of this site. Gary
https://groups.yahoo.com/neo/groups/LittleSolarBoats/conversations/messages

What MPPT are you using? I'm considering integrating semi-flexible monocrystalline panels and an MPPT into a velomobile build. I should be able to fit 400W on there, though less than will receive direct sun at any point. It would be great if I got as much output as you are right now.

It's amazing how even just 100W can add up when that's all day long.