I'm currently working on planning out a solar
system for my (power) boat
. I'd also like to add an inverter
to the system, although I haven't decided yet if that'll happen this winter along with solar
or if the inverter
I think I've decided on going with Victron gear
for pretty much everything. Inverter will be a Multiplus 12/2000/80. And I'm thinking of going with the Cerbo GX + touchscreen to tie it all together. And a smartshunt for monitoring (to replace my current
Blue Sea SoC meter). The house bank is currently 2x L16 AGM
6 volts (400ah at 12 volts). I think I'll be up for new batteries
next season, but I don't expect to change the basic design of the house bank unless I can somehow stomach the (almost double) cost of 3 of the L15+ 4V Firefly batteries
(and then have to rebuild
mounts for them).
The big question is around how to configure the solar panels
. I have a slightly awkward space for solar panels
(on the cabin
top forward of the windshields). The space is basically 90" x 100", but the catch is that I need to maintain a walkway up the center and across the windshields to access the windshields for cleaning
, etc. So I've figured I basically have a pair of 36" x 84" spaces to fill with panels
. This unfortunately restricts me from just using a pair of big 300+ watt panels
, as they're all too wide to leave an adequate walkway. And the 200-ish watt panels are all too big to fit 2 of them per side, but just 1 leaves a good bit of space un-used.
Within the available space, it seems like the most solar I can fit is 600 watts, in the form of 6x 100W panels. The 100W poly panels from Newpowa are 35.83" x 26.57", so I can fit 3 per side, basically consuming a 36" x 80" space.
So the question comes down to how to wire the panels and what charge controllers to use (definitely MPPT). I've come up with a few choices:
- 2 series strings, each with a Victron 100/30 controller
- All 6 panels in series on a single Victron 150/45 controller
- 2 series strings in parallel on a single Victron 100/50 controller
- 3 series strings, each with a Victron 75/15 controller
The last 2 options are a little cheaper than the first 2, but we're only talking about a $100-ish spread between the cheapest and most expensive option, so cost isn't a big driver.
Shading isn't a significant concern. The forward pair of panels on each side should never experience shading other than from a person walking past (unless we're at a dock
with tall stuff around us, but then we're probably plugged in anyway). The panel on each side closest to the windshield may get some shading at very low sun angles, but will be un-shaded through most of the day.
Based on those controller and wiring
layout options, what does everyone think the most effective option will be?