400 Watt Bimini

[waterdog]

I almost forgot.   The solar panels have a pretty cool charge controller system.   I wired the three panels in series.    That gives 63 Volts going into the charge controller.  Which is great.   Big Volts means smaller Amps which means I didn't have to run massive wires to the charge controller.   The charge controller actually does an inversion to AC and then converts back to DC.  The idea is to always run the panels at the maximum power output while still giving the batteries the correct charge voltage.   Disconnect the two and don't make charge voltage sunlight dependent or run the panels suboptimally.   Supposed to be a really efficient way to go.    It has full three stage charging plus a programable equalization function.   

And the part I really like is that it has a load shedding feature.   There's a 20A circuit that shuts off if the battery drops below a threshold voltage and starts up when it's above another threshold.   So it's possible to connect load like refrigeration to the load controlled circuit (this serves the load from the battery - it's independent of the panels - would work even if plugged into shore power.)   

So we could leave refridgeration on and go exploring inland.   In the worst case scenario, we come back to some smelly food but we won't have killed the house bank.   

I'm going to bury my shore power cord in some deep, low, unreachable place.   

[Craig Illman]

Steve - Looks like a nice place for a sea gull nest. 

Craig

[Hawk]

Steve,
Nice set up on the solars. Cold Coronas forever.
On another equipment note, I recall you changed out your autopilot...what did you install and from whom?
Thanks,
HAwk

[waterdog]

Hawk:

I bought a Raymarine X5.  Unit failed with less than 10 hours.   Gearbox dead - fixed under warranty.  I'd like to say all kinds of things about this unit that I probably shouldn't say in a public forum.   I will say this is a lightly built unit which I think is marginal for our boats.  For that matter I wouldn't put it in a 30 foot boat.   Wouldn't buy the same unit again.  I don't have the time to rip it out and put in something different.   

Now my solar panels are Kyocera 130s.   Arrived in perfect condition.   Met their specifications and impressed me!   

[Hawk]

Steve,
Thanks for the tip on the pilot as I'm desperately trying to get my 4000 up and running to avoid X5s, S1s etc.

By the way was that you waving at me on Sunday morning as we passed out front of Centre Bay in 20 knots...unfortunately right on my nose and late for son#2s baseball playoff game. You had a nice run going though.
Hawk

[waterdog]

Hawk,

Yes that was me waving.   We were happily cruising along at 6 knots with the genoa.   I didn't even bother taking off the mainsail cover - I figure with all those solar panels we look like lazy cruisers anyway.  We might as well act the part. 

Steve 

[Hawk]

Thought so. Although, it was a little early in the morning to have your Margarita blender plugged directly into the new solar panel power source, wasn't it?
Though you have to get used to the Mexican life style somehow!
Hawk
 

[tonywright]

Steve

Your installation looks and sounds impressive. Some questions for you:

1) Was the overall electrical design your own, or was it supplied by the manufacturer of the panels?
2) How did you fabricate the connections to the bimini frame?
3) How easy would it be to remove the panels for maintenance/winter decomissioning?
4) By having them in series, does this mean that if one panel fails the whole system is offline?
5) Did you reinforce the standard bimini frame in any way?
6) Any concern about the additional loads on the bimini frame when heeled in a blow? (A couple of us in the club have discussed installing panels in this location, but assumed we would need some kind of reinforced arch.)

Thanks

Tony

[waterdog]

1) The panel manufacturers really only supplied the specifications.   If you do some reading, you will likely be drawn to MPPT charge controllers.  Outback and Bluesky are a couple of names that seem well regarded.    I used a BlueSky 3024i.   Believe it or not, connections to the controller and the settings for the controller are identical for 12V and 24V batteries and series or parallel installation.  It really doesn't matter what you connect to it, the controller will figure it out.   It is not a complex design.    The biggest issue was sizing the system and I followed the same philosophy as my anchor design.  You can't have too many electrons.  I assumed doubling my current cruising load (tropics for the fridge, fans, watermaker) and did the math which crudely was as follows:   

100 Amp hours per day
@ 12V
= 1200 Watt Hours
/ 8 hours of strong daylight
= 150 Watts Capacity
* 3  (the fudge factor)
= 450 Watts

390 Watts met the asthetic criteria.
The fudge factor allows for inefficiency (I am not going to adjust panels to face the sun and clean them every day) & extra load (because you never know). I don't have much data yet, but I think this was a very conservative design.   No Honda generator will be in my aft locker. 

2) I have two bars that support the panels mounted on a standard bimini frame.   The bars bend around and have a nut welded in the end.  Bolts pass throught the bimini frame and into the bars.   The design allows for the bars to rotate forward or back so that I can make adjustments on the bimini and still level out the panel array.   The panels themselves mount to the bars with straps bolted to the panel frame.   I have neoprene pads so nothing rattles.   The bar ends are nicely finished and have fittings that mate to the round surface of the bimini tubing.

3) 12 nuts.   3 electrical connections.  Maybe 18 minutes.

4) Yes!   But don't let that dominate your decision criteria.   Parallel installations are much more vulnerable to shading.  A mast shadow across a panel could drop the voltage for entire installation below your charge threshold and give you zero output.    That could happen daily.   The likelihood of my system going down with a panel with a 20 year guarantee is small.  If it did happen, I would have ten minutes of wiring work to do bypass the bad panel.  (Following the 2 hours of diagnostic work to figure out what the problem was.)  I wouldn't even consider wiring the panels in parallel.

5) Yes.   It's 1 inch tubing (common anyway).   There are no straps.  I have struts aft which lock it up both fore and aft and side to side.   I have struts forward for extra support.   There is some movement side to side at the forward part of the bimini if I push it.   It may wobble on it's own in winds at 30 knots plus (didn't budge in 20 the other day).   I will fabricate some blocks that will go around the backstay bridle and lock it up entirely.   

6) Yes.   I used standard bimini type hardware and it still has set screws in the fittings.   I don't like set screws in end fittings and plan to drill and through bolt before going down the coast.   Once that is done, I will not be worried in anything up to 40 knots.   And once it gets to 40 knots I'm going to have a whole bunch of other things on my mind other than my bimini, like how to gain leeway because every damn port down the coast has some unsafe bar in a breeze...

[waterdog]

I had a thought.  One thing that is annoying is the 400 different opinions that you run into and the mythology that you have sort out before you do a system like this.   You'll bump into somebody at a boat show who will tell you that the sweet spot for solar is 80 Watt panels.   Best bang for the buck etc.  And they were, three years ago.   You would kind of just like to know what to get and where is the cheapest place to get it that has good service and not spend a month researching and sorting it out.   So here's the skinny:

Kyocera panels - 130W x 3 - buy them here: http://store.solar-electric.com/   they have inexpensive shipping options $538 ea
BlueSky 3024i controller- $345
Add a circuit breaker, some cable and shipping for $200
Have your favourite boat guy fabricate some bars and add some struts with standard end fittings (for this you may have to sew a bosun's chair and redo the cushions in your rigger's boat - cash is also a viable means of payment in many jurisdictions).
Make your own mounting straps out of stainless steel - I used the solid part of hose clamps.

Warning:  I think this will yield a great kit that fits well in a C34 for typical+ electrical loads.   But...   I moved the split in my backstay up to accomodate a perfect fit on my panels.  I don't know how wide the split is on a MKII.  Might be perfect or a little wide.   Cut some pieces of cardboard and throw them on your bimini to test the fit before you order.   You won't fit a panel between the split on the backstay of a MKI.   But you're really tired of bumping your head any way, so add a riggers bill to your total and get it done!

[Terry Forshier]

without reading all the thread and just looking at the end product I think you might have just put up the sloar and figured a way to connect them to keep the  rain out and forget the canvas.

[waterdog]

I actually started with the thought of making the panels the bimini, but couldn't think of an easy way to make it drip free.   I couldn't join the panels directly to each other without going to a rig without a backstay.  Maybe the gaps between could be filled with pool noodles and silicone...

[Bob Kuba]

Added to the Wiki
http://www.c34.org/wiki/index.php?title=Solar_Power