During mid-May in La Paz, BCS Mexico, at 24 degrees North, the four solar panels produce power as follows:
9 AM - 10 amps
11 AM - 2 PM 25+ amps
4 PM - 15 amps
7 PM - 3 amps
The four solar panels are mounted on an aluminum arch built by Atlantic Towers in New Jersey. The arch is made from round 2" aluminum tubing. The tower is very strong, I climb on it to clean the panels.
The blue fitting on the stern, just above the swim step, is the mount for the Sailomat wind vane. When we are at anchor we remove one bolt and then remove the Sailomat. We can then use the swim step and ladder as needed.
We carry a 2 HP Suzuki outboard as a spare in case the 9.8 HP Nissan fails.
The shore in the distance is the El Magote anchorage and peninsula on the north side of the La Paz inner harbor.
In the picture to the right you can see the round Anchorlina reel that holds 180' of 2" webbing that serves as the anchor rode for the 22 pound Danforth that is carried next to the Anchorlina roller. We use 15' of 5/16" BBB chain with the Danforth.
The triangular set of stainless tubing sticking out aft from the arch is the hoist for the outboard. We use a 4:1 block and tackle with 1/2" line to raise and lower the 61 pound Nissan from its mount on the stern pulpit, just aft of the Lifesling.
We have a 35 watt light mounted on a swivel on the solar panel arch. That light can be seen on the far side of the arch. We can sit in the cockpit and read at night or we can work in the cockpit with a real BRIGHT light on.
Each solar panel has it's own junction box and is independently wired to the common junction box mounted on the bottom of the top rail of the arch. You can see the 0/2 battery cable hanging down from that box , just to the right of the backstay in the center of the picture.
Each solar panel can be connected or disconnected from the system independently of the others.
There is 20' of 0/2 battery cable connecting the common junction box to the 12V bus bar in the engine room. The battery cable runs thru the inside of the forward 2" tube of the arch, down thru the deck, and into the engine room.
This picture was taken while in the Chula Vista Marina, just south of San Diego. That is the fishing pier in the background.
I get lots of questions about the strength of the arch, the panel mounts, and the panels themselves. Folks seem to be concerned about the panels staying on the arch in strong wind and waves.
We have twice sailed offshore in more than 30 knots with gusts over 45 and waves of more than 10' with the boat heeling to 20 degrees. At no time did the panels look or sound like they were under any stress.
We have a lot of experience sailing Mirador in up to 55 knots of wind and the panels have never creaked or moved.
Mirador spent over eight hours on her side with the panels at 40 degrees to 40 knot winds gusting to 65 knots. After Mirador was refloated and securely anchored - we inspected all the panels and mounts and found absolutely no damage.
The picture below shows the extreme situation that would put the maximum possible stress on the solar panels and from which; the solar panels and arch suffered no damage. In the picture below, the wind is blowing straight onshore at 35 gusting to 45 knots.
Engineering calculations, (very rough!)< show that the total wind load on the arch and panel structure would be about 268 pounds in 35 knots gusting to 45 while heeled at 45 degrees. Even in 60 knots of wind with the panels at 45 degrees to the wind - the wind load is only 55 pounds per mount and there are two mounts per panel.