[C320-list] Solar panels on bimini

[danny jensen]

Scott,
My solar project is documented here along with others. I have a video also.

https://c320.org/mediagallery/search.php?keywords=solar&mode=search&swhere=0

Here are some of my thoughts:

   1. My victron MPPT controllers are tied to my battery via my charger
   wire run so I did not need to make a long run to my battery from aft to
   midship.
   2. Shading is a big issue at anchor. Need separate MPPT controllers I
   think.
   3. Flexible panels are generally not a good idea for durability long
   term. Furthermore, I don't have 200w of load when I'm not on the boat. The
   flexible panels  live in the forward cabin and I rig them for my trips. I
   have 2 x 200w flexible solar panels.  I strap 1 to the top of the dodger
   and one is strapped on the depending on the direction of the sun. . If I
   needed to keep my battery alive, while away, I would consider a small rigid
   small (10-50w see this link
   https://www.altestore.com/store/solar-panels/alte-solar-panels-p40768/#ALTS-10W-12P
   )  panel mounted so l could stow it quickly and use the flexible . I would
   consider hanging the small panel off the stern pulpit with magnum bbq
   hardware so you could change the tilt at different times of year and just
   run an mc4 extension cord to it using existing vent holes
   4. I have MC 4 connectors I stow in my line bag after they run through
   deck near the port locker and use MC4 extension cords when deploy the
   panels. I use the autopilot and I need the extra power of 1 100w flexible
   solar panel on the dodger while sailing on longer trips
   5. I have a solar sub panel in the port locker. See pictures.
   6. 200w on most summer days is enough and I don't need to run my engine
   except for creating hot water.
   7. Provide your number and we can talk more if you like.

Danny

On Tue, Mar 5, 2019 at 12:24 PM Scott Thompson <surprise at thompson87.com>
wrote:

> I have a new bimini on order (now under construction) and want to have
> solar panels installed on top of it. I'm getting ready to order panels.
>
> In anticipation of this, a few years back I installed a Victron MPPT 15
> solar controller and ran wiring to the stern. I've had a lightweight but
> not flexible panel tied to the top of my old bimini for the last few
> years and it has done a fine job of keeping the batteries topped off
> when we are not on board. (Surprise lives on a mooring and is rarely
> connected to shore power.) Now I'm looking to increase the total amount
> of solar power collected, as well as making the installation more
> permanent and less ad hoc. This leads to a few questions:
>
> Have any other 320 owners done this? If so, what is documented about the
> experience? Any tips? Dos and donts? Brands or designs that work well or
> do not?
>
> The bimini has three sections aft of the middle bow, divided by two
> zippered slots so that it can go around the split backstay. I'd like to
> install three panels. The middle section is much larger than the other
> two, and therefore has room for a larger and higher output panel. I had
> been planning to add three panels -- one in each of those sections of
> the bimini -- wired in series for a maximum total voltage of 36 volts
> approximately) that will be stepped down to normal charging voltages by
> the MPPT controller. This is supposedly the advantage of MPPT
> controllers over older designs -- that you can harvest more energy by
> converting excess voltage to amps through the step down process.
>
> However, I've been warned that I shouldn't put different sized panels in
> series -- that the power will be limited by the smallest panel if I do
> -- and that it's not a good idea to wire panels in series in any case
> because a shadow on one panel reduces the output of the other two as
> well. These same sources suggest that a better way to do it is to wire a
> separate charging circuit for each panel, meaning three MPPT controllers
> and three cables running up the backstay to the bimini. I'd rather keep
> it simpler. Does anyone have any thoughts about the best approach here?
> I'm not too worried about shadows on the panels given that the boat is
> usually on a mooring and so the only shadow to worry about is from the
> mast. So perhaps my best approach is to keep the three panels wired in
> series but size them equally, which means giving up some area on the
> middle one.
>
> Any related thoughts or advice will be welcome. Thanks.
>
> --
> Scott Thompson
> Surprise, #653 (1999)
>
>