630W Solar Array

[swiftibis]

Hello all,
I just upgraded my solar capability, and I wanted to share my rig on my Pearson 367.  The ketch owners might be jealous of my bimini configuration which appears well suited to an install like I've done, as the panels are unobstructed and out of the way. 

I started with 2x 120W, 12V used Kyocera panels, one of which was toast.  I had the functioning panel plugged into a Xantrex 60A PWM charger, and the setup did ok.  It generally pumped an amp into the batteries which was offset by the 3.5A out for the fridge unit, so roughly 4.5A in good sun.  This meant I could go from 5 days without charging to roughly 10, with power rationing in the evening. 

Anyway I just installed 2x 255W, 24V Lightway panels connected to a Blue Sky 50A MPPT charger.  Now, I'm aware that this is quite overkill but the panels were far less expensive at about 180$ each than even cheap 12V panels.  Conveniently, the panels are the same size as my bimini so I'm happy how they act as a rain guard (bimini fabric leaks), and they only weigh 17 pounds each more than a comparable 12V panel.  I strung the working 120W panel off the back of the bimini and tied into my davit stiffening bar.  I found I had far more power than I needed on my main bank of 4xTrojan T105 6V batteries from the 2 big panels, so I plumbed the small panel into my starting battery.  I might remove this eventually to save weight on the bimini.  I live aboard at a dock, but I've had my AC battery charger deactivated since I installed the rig.  The batteries drain down about 10% every night (I monitor with a Victron battery monitor) but are quickly recharged, even though it's been very cloudy and rainy lately.  I suspect these will work perfectly in the winter.  I've seen as much as 25A going into the batteries which is pretty good, and I also suspect it could be better if the batteries needed it.  So for a boat to sit at anchor, I feel like it's plenty of power to run all my lighting, fridge, laptop and really anything I might want to run off the inverter.

So, adding 90lbs on top the bimini is not something I'd generally prefer to do, but I've stiffened the frame up considerably and run a cross-support so my stiffeners bear the load instead of the bimini frame.  I haven't been in anything nasty offshore yet, but big motorboat waves don't seem to perturb the system much.  I think continued wave action may necessitate modifications to the design from a fatigue perspective.  If a big wave lands on top it might also be a bad thing.  I'm going to use grey sticky butyl and a strip of plastic to watertight the gap between the panels.  I absolutely need to drill holes where all those little worthless pintle set screws are and replace with thru-bolts or rivets, and that's on the todo very soon list.  My main regret is that I can't dismount the panels and bring them inside through the companionway (39" wide) if there's a hurricane, but I'll probably put them in somebody's garage and hope for the best.

Anyway I'm going on a 5 week cruise down to south Florida this winter.  I hope my efforts were not in vain, and that the system performs well in offshore waves.  If the whole bimini SS tubing thing fails me, I plan to build a double arch out of a wood like fir and then glass the hell out of it.  I actually wish I would have done that instead, it would have cost far less than the SS tube and fittings, and I'd have much more control over the load paths and would feel better about its structural strength.
Mike S
SV Tardis, Pearson 367 #26

Pictures available here:
https://drive.google.com/folderview?id=0BytoKu-zUfyrZV90RVJtQW1LTlE&usp=sharing

[SVJourney]

 You are right, THIS ketch owner is jealous!  

[Randy]

Looks great Mike. I like the dodger and bimini too. More photos please. I too have a sloop.

Randy
S/V Venture

[Della and Dave]

Looks really nice, and more importantly sounds like it works nice too.

[swiftibis]

Little update,
Since I installed the solar rig I could sell power to my neighbors.  I haven't used the battery charger once since my last post.  My batteries don't get below 85% and I am using power with reckless abandon. I live full time at a dock, and I run all lights and other things off the batteries.  The past few weekend trips I left the inverter turned on and despite flagrant use I always had ample power.  I was toying with the idea of stressing my inverter and using the AC water heater but that is a little crazy.  Anyway I am very happy with the production levels and I suspect it will do well throughout the winter.  Even with 4 days of overcast it still charged a few amps.
Cheers!
Mike Sytsma,
S/V Tardis 367 #26