Solar Install Part 1: Planning

So after spending at least a year whining that my battery bank is too small, I can’t generate power etc etc I’ve decided to FINALLY do something about it, spurred on by the discovery of $130 6V 220 AH batteries at the local costco (they don’t put them on the website).

So, first stage is to buy and install 2 6V batteries, giving me a battery bank of 220AH, as opposed to the old 70AH. Tripling the battery bank for $260 – not bad! Not the long term solution (that’s 400AH lithium) but it’ll tide me over for a year. Hahahahahaha ‘tide’, get it, hahahahahaha *tumbleweed*

Now the hard part – working out where to put the solar panels.

For the longest time I planned on fixed solid panels on an arch. This of course, meant building an arch, an expensive and difficult project that continually got pushed back because seriously, building a stainless steel arch sounds like SUCH a huge pain.

Until I had a brainwave! Semi-flexible panels have CRASHED in the last couple of years, now under $2 a watt. I grabbed two of these 100 watt panels  and am going to mount them directly on the deck! Again – long term I will have an arch with more solar (I can probably cram 400 watts on there) but this will do for now, as my power consumption is really low.

I plan to mount these two panels in two places – one on the ‘slopey bit’ where the cabin roof turns into the deck, and the other on the cabin roof just before that.

solar

I’ve circled in red where the panels will go.

Now, these are not optimum (esp the front one) but they are low cost and should put out enough power to really help out. And for less than 400 bucks, its hard to go wrong!

I got this controller  with this display

Max 20 amps, which should cover both panels, again for under $200. I went for an MPPT controller as for a bit more, it really optimizes the panel output.

ANYWAY, this is all the plan, I’m sure it will have to be modified when everything arrives and I measured it wrong or something else super dumb as I subscribe to the ‘measure once, cut wrong’ philosophy of workmanship.

Long term plan is still to have 400AH of lithiums with 600+ watts solar but this setup should get me around the island in August.

 

Matt

7 Comments

  1. Nice!
    I don’t want to be the voice of doom… but any shading on the panel (like a line or even a flag shadow, not to mention sails!) reduces there output drastically!
    I know, real bummer.

    • Yeah I saw that, but figured if it was the difference between 0 amps and a small amount, I’d at least try it. There are at least a couple hours each day where they would be uncovered – I think! (think being the main word here)

      I am not going to permanently mount them at first, for that reason. If they REALLY suck, I’ll move them elsewhere.

      Man, trying to find a good spot half makes me wish I had a powerboat with that flybridge! (not really)

  2. I am going to ad some more bad news to your solar plan. We currently have two of these panels mounted on our bimini with Velcro. Performance wise we are happy but need to get to 400 watts to really cover our daily use and add a small watermaker. But that’s not the issue.

    From what I have found all of these cheaper semi-flexible panels come out of the same factory in China. Grape, Renogy, HSR, etc. they just get different stickers and boxes. We have the Renogy ones. Several of these companies have stopped selling these panels and at least two have began a recall process.

    The issue is the panels can heat up and cause damage or fires. I spent a lot of time talking to Renogy about this and apparently the issues that their panels had was a fire started on a Bimini in an installation like mine and a deck that was melted and discolored in an installation like you are talking about. From what I gathered the cause is three fold. First improper installation where the panels flex against a hard point like a bow in the bimini. This has been known for a long time and the higher end companies like solbian have literature about the installation to not install them in this manner. The second issue is the lack of air flow in on deck installations. You need food air flow to keep the panels cool. The third issue is internal shorts in the panels. Again Solbian has warned about this in the Chinese knock off panels. I thought they were just using their additional quality control as advertising but it appears to be more than that.

    Sorry to bring bad news. I found out about this issue the day before we crossed over to the Bahamas. When we get to the USVI we plan to change our solar setup and return these panels under the recall.

    Good luck and fair winds.

    Oh and on the tower, most of the towers we see out cruising are aluminum not SS. Many of them are the tower in a box kit from Atlantic Towers in New Jersey. We wish we got one before we left the states. Pricey but less than a custom made one unless you can do your own welding.

    • Hey Jesse,

      I actually think I recall reading about that issue on your blog last year! (Also, that’s a nice looking wiring install/run)

      It’s a big worry for me – I think for now I am going to use 3M industrial velcro to install, and then monitor the temperature. If it’s getting real bad, (or is too shady), I have a back up plan involving swivel mounting off the life lines, though this is not a ‘set and forget’ install. I have a IR temp gun, so I will definitely be checking.

      Did you notice any temperature problems with your setup? I will check out that tower box kit, thanks!

      • I monitor my panels with an IR gun and haven’t noticed any temp increases.

        It is a problem. I was willing to accept some quality problems and performance issues by going with the cheap panels. But now that it’s safety issues I am more concerned. I am still not convinced that the issue isn’t an install one.

        For your setup take a look at Sundowner Sails Again. They used a thin plastic sheet to add a little pit of the stiffness. That could work for your install plus give a little protection to the hull.

        Good luck

        • So the IR gun doesn’t show an increase? Hmm.

          Your install looks very well done, so I’m not sure its an install issue. I’ll look at SSA install – that plastic sheet sounds like a good idea. Also wondering about putting some kind of heat insulating/protection material under it.

          Anyway, a lot to think about. I really think I will do a temp install using industrial velcro and monitor the situation. When do you pick up your new panels?

  3. Howdy from dirt in Montana. I was a cruiser wannabe, so I do understand more about your world than you would expect. I will not start commenting on all of the blogs owned by people who click my solar blog, but if you send an email we can talk as I have time. Two things learned along the way: Lack of cooling under panels raises their temp and heat causes a drop in voltage that can kill the ability to charge. Don’t know about any fire issue. The other is that a shadow across a 36 cell panel that shades 4 cells will shut it completely off. Running lengthwise, the same direction as the shadow makers, is better for this. People I hear from on sailboats generally need to double their systems so that when one side is shaded the other still works.

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