Ok so I always hated the way solar panels look attached to the back.
So I removed the 65W panel I had and replaced it with two flexible 50W panels. Bonded them down and you can step on them. They probably will be kinda slick when wet but they are in a place that you can avoid.
Only went out for an hour or so and the voltage never dropped below 13v. Had radio, GPS, Autopilot all powered up.
I am having difficulty getting the controller voltages set up the way I want. If I were to do the controller over now I would go with the Victron Energy controller and put the panels in series.
I'd love to do that but that is exactly where I stand to raise the mainsail on our . I wonder how much "standing on" they can take?
High heels are probably not good, For the solar panels! My guess is they will stand well to standing on them. I walked across them all day yesterday just to get the feel and they never moved and felt solid.
High heels are probably not good, For the solar panels! My guess is they will stand well to standing on them. I walked across them all day yesterday just to get the feel and they never moved and felt solid.
For a mounting under the main sail vs. off the stern I'd factor in some fairly large differences in expected output. Shading from the main or lines even running across the panel is going to hurt performance. Even with shading a panel can probably put out it's rated 17-18 volts but the amps it puts out (the important part) is going to drop way down. Measure the amp output and then partially shade the panel with a line or the sail and watch the amps go down.
The same situation is also a killer if you run two panels in series as partial shading on one will kill also the output of the other as it limits the current running through both. Putting panels in series on say a houses roof that never receives shading can have some benefit in that you can run a smaller wire from the panels to the controller without line loss. On a boat I'd stay with them in parallel. Then if you get shading on one you would still get a higher amperage output from the other,
The same situation is also a killer if you run two panels in series as partial shading
Wouldn't attaching two solar panels in series actually double the voltage at the end, just like it does with two batteries? If that is the case, that would be harmful in a different way, too, since controllers are oftentimes rated for 12 or 24 volts. So putting the resulting 24 volts through a 12 V controller would also seem to be a bad idea.
Just wondering....
My two panels are in parallel. Besides, they were advertised specifically as being somehow "fool-proof" against partial shading (which, like Sumner pointed out, most other panels are not...)
The same situation is also a killer if you run two panels in series as partial shading
Wouldn't attaching two solar panels in series actually double the voltage at the end, just like it does with two batteries? If that is the case, that would be harmful in a different way, too, since controllers are oftentimes rated for 12 or 24 volts. So putting the resulting 24 volts through a 12 V controller would also seem to be a bad idea.
Just wondering....
My two panels are in parallel. Besides, they were advertised specifically as being somehow "fool-proof" against partial shading (which, like Sumner pointed out, most other panels are not...)
My upgrade was more for aesthetics and performance (not solar, less wind drag on the stern). The 65W panel was suffecent for me on the stern. That is why I did 100w on the deck. As far as shading one panel reducing the output of the other panel is not correct if you have a pass thru diode on the panels. When I removed the conector block from the back of the panel I removed the pass thru diode. Not an issue since they are in parallel. Probably their "fool-proof" design. In series the max voltage would be 40v+ that is why you have to use a MPPT controller that can convert the higher voltage to current not just bleed it off.
For example I have enough power daytime, but in the morning and later afternoon it could be more.
So I guess 2 seriall mounted panels in combination with a MPPT controller could help to produce power in these times. And the shade of the main probably will not harm so much.
Ok was out at the lake yesterday afternoon and did some checking. The sun was at about 45 deg. This is the pic of the shading.
One panel has a corner shaded that does affect output. Other panel is in close to full sun. I had radio, GPS, autopilot NMEA 2000 powered up that included wind indicator, GFS10, GMI20, RC42, AP24, speed depth and temp sensor. Battery was still charging at a .1a or so. Boat sailed well and ended up crossing the finish line within 4 seconds of a Macgregor 26d and a Cat 30. With the time conection should have ended up 2nd overall. The Person 30 did well since there was 2 reaching legs. The Cat 30 did well also but hit a mark and had to go around again.
Catigale is probably close, but possibly on the high side. I will have to do some checking. With all electronics going not including autopilot surges. I am 2 o 3 amp of draw. As long as one panel is in sun at least a 45deg angle it has been able to keep the charge/discharge real close to 0.
. I wonder how much "standing on" they can take?
