Vertical solar panel

ctva · 4 Aug 2024

I’m with onesea. We have vertical panels, 2x100w at the spray dodgers. Never get in the way when sailing or at anchor or in the marina. No windage. Can tilt with a small length of rope to the back stay if needed. No ugly structural metal work required.

This has been discussed before, Solar Panel Question... shows a pic of my set up.

We are on the west coast of Scotland, not the sunniest place and they have worked brilliantly. This summer we have been running two fridges (long story

) with no issues.

thinwater · 4 Aug 2024

Spray dodgers are rare here, so yes, windage here. No windage for you. Also, the original topic related to getting full sun on both sides, which would have meant mounting them vertically on deck, not a railing. Obviously impractical. That is what I was getting at, not railing mountings, which are well proven in their utility.

Remember, one size does not fit all. On a cat, I have never been short of flat space. Different. The idea of having to move panels seems like a pain to me. I wouldn't do it most of the time. Also a different subject.

I don't think anyone mentioned that vertical panels run cooler (0.3% per C) (better convection and one case where more wind exposure helps). Even more important in more southerly areas. A minor correction, but it all counts.

In the past, panels were expensive and maximizing output was everything. Now that panels are $1-1.50 per watt, in real money, they are incredibly cheap. Perhaps it sounded like I was anti-vertical. Not true. I explained why they are not better than flat on a boat (they can be in a solar farm), but that does NOT mean that I think placing them anywhere they are out of the way is a mistake. So what if they put out 1/2 what an optimally positioned panel might. They cost many, many times less than they used to. Rigid panels are most durable, but semi-flexable panels can last well if mounted to rigid surfaces, such as a cabin side. They are also very light and easy to mount on stiff surfaces without compound curvature. You will also need multiple controllers, but they have become cheap as well. There will be more wiring, but it will be smaller gauge.

If I used spray dodgers that would be a great place.
I would look at the cabin sides. I might even have windows I wouldn't mind blocking.

The main consideration is that they are in a place where they are safe from damamge. It would be great to see more builders incorporate this into their thinking. Boat with panels integrated right into the deck are neat, but what a royal pain they would be to replace in 15-20 years. Most likely, they become abandoned in place. Sloped surface where you don't walk offer interesting possibilities.

thinwater · 5 Aug 2024

Two interesting graphs. The output of solar systems summer and winter, in Germany. The project related to large grid farms on agricultural land. Note that shading from adjacent rows of panels was not included, which seems odd.

Two interesting take-aways:

A mix of vertical and inclined panels smooths power production through the day. Important for grid systems, not so much for sailors.
Vertical is better in the north (very few US sailors are this far north but many UK sailors are) and in the winter (few of us cruise in the north in the winter). Inclined is better in the south and in the summer.

I think the point is that the best orientation depends on the project, and that both vertical and inclined are the right answer sometimes. Clearly, now that we have bifacial panels for not much more, we will be seeing a lot more vertical farms. Perhaps not on boats, but on agricultural land the improvement is obvious. And there are other advantages (construction and maintenance). Snow coverage is a big factor in some areas; inclined panels must be steep enough for it to slide off and flat can fail for long periods.

Cool. Thanks to the OP.

Summer