Pudgy solar dinghy

[IGBT]

Pudgy solar...hmm...
I was moving around some stuff in the pole barn and saw some new Renogy 100 watt solar panels we had from another project a couple years back that never were used. I stacked one on our Portland Pudgy then another and another until four of them seemed to fit almost perfectly.
Hello? What about having some little quick connect to fasten those down to the Pudgy and then feed that power back to our M17 while we are towing the Pudgy? These panels are about 15 pounds each, aluminum frame glass, pretty standard I guess, 3 years old but still new in box. I have 12 of them so it would be a fun test at least.
We still plan on 600 watts of flexibile CIGS solar on the boom tent, but this would give another 400 watts and perhaps a bit higher output per panel watt since there would be lower shading (if the Pudgy is being towed well behind the M17).
I could feed the power forward at 20V, 20 amps, 40V 10 amps or 80V 5 amps. (4p, 2s2p, 4s). I was thinking I could use a 12 gauge outdoor power cord, one of the more rugged ones, and cut the ends off. A safety idea I had was to make use of the three conductors in that wire (hot, neutral, ground) and implement a small relay at the panels in the pudgy, rigged in a way that 12V power applied over the third conductor would activate the relay and allow the solar panel power to flow over the other 2 conductors (20V, 40V or 80V). In this manner, any break in the cable would cause the relay to open, disconnecting the solar array from the wiring. Just an idea.
We might do a test of this next week, after the 107 degree Sunday.

 

[wpns]

Looks like a fun project if it doesn't bounce around enough to crack the panels.

 

[IGBT]

Looks like a fun project if it doesn't bounce around enough to crack the panels.

Thanks. The plan was to add some stainless eye hooks to the panel edges after hinging each two panels to each other (I have some of these 6 inch aluminum piano hinges from some other project which are perfect). This will create two hinged double panels which we would then use the eye hooks to lash down to the gunwale on the dinghy (it has some various attachment points).

My aim is to use this on the high power demand river system, especially when fighting current with our 6kW electric motor (not run at full power though). Should not be as much bouncing as a big lake or ocean, except when the half mile long barges go by on the Mississippi.

 

[wpns]

Thanks. The plan was to add some stainless eye hooks to the panel edges after hinging each two panels to each other (I have some of these 6 inch aluminum piano hinges from some other project which are perfect). This will create two hinged double panels which we would then use the eye hooks to lash down to the gunwale on the dinghy (it has some various attachment points).

My aim is to use this on the high power demand river system, especially when fighting current with our 6kW electric motor (not run at full power though). Should not be as much bouncing as a big lake or ocean, except when the half mile long barges go by on the Mississippi.

Can't wait for pictures!

 

[IGBT]

I put piano hinges on the edge of the four panels to make two hinged pairs. I found these 6 inch aluminum piano hinges in my parts junk box that evidently I had ordered 5 years ago from McMaster-Carr and never used. I have no idea what I bought them for back then but they were perfect for this, three per 100 watt panel edge to make a 200 watt hinged panel pair. I think this makes attachment to the pudgy a little bit easier as I was able to just put four total stainless steel eyelets on the panel pairs to attach to the Pudgy.

I have it set up in the yard today and had it feeding into my new Victron 150/35. I had discharged one of my 48V banks to 90% the other day for testing and it started charging with this solar Pudgy at about 270 watts. Not bad for not being directly pointed at the sun, in Washington state, with some smoke in the air from the Chelan, WA fire. Unfortunately, it charged up my 48V bank really fast and had hit full charge before the sun got to peak. Probably not going to see more than 300 watts out of the 400 watt panels in these conditions.

Hopefully will get it out on the river this coming Thurs or Friday. Thursday is sunny 86F but with 5 to 10mph winds and Friday is sunny 86F winds light and variable. To compare with our last 24nm trip up the river where we used 500 watts for 6.5 hour trip time, we really should go Friday, since we had no wind on the first trip not towing a dinghy.