Adding solar power

Marathon FL
Posted by Bill

We debated back and forth about adding solar to our boat. We have a Honda 2000i companion generator that we use to charge our battery bank when we aren’t tied to a dock and shore power, but with our current battery bank, we need to charge at least once a day and can’t leave the boat for longer than one day. There is much debate as to the economics for solar, but after dealing with battery issues for 5 months, anything that keeps the batteries happy is worth consideration. We opted with flex panels rated at 135 watts. We purchased 3 panels, which generate 8-10 amps per hour each at optimum condition, and normally will give us a total of around 120 amp hours per day. This is close to what we use each day, so at best, we will only have to charge the batteries a few times per week when we are not attached to shore power. We got the one panel in stock and backordered the other 2.

We worked with a company called SALT – Solar, Air and Land Technologies, here in Marathon. They have a great reputation in the cruising community, and one of the owners keeps his boat here in Harbour Cay Club where we are staying. Double bonus. We looked at fixed panel solutions and flex panel solutions, both using Sun Power cells. Sun Power has a 23% efficiency rating and will work at better angles to the sun than most other panels which have an average 18% efficiency rating. They cost more but the price per kilowatt hour per square inch of panel is better than anything else out there. The fixed frame panels were going to require major modification of our bimini frame with substantial cost involved just to mount them. Flex panels can be mounted directly to the canvas bimini cover and can be bent to a moderate curve radius. We chose to sew industrial grade Velcro to the bimini with a wrap around flap to velcro to the top of the panel. The panel is attached with velcro to the top and bottom of the panel. In addition, we installed grommets to the corners of the panel and anchored them to the bimini, if for some reason the velcro doesn’t hold (overkill in retrospect). Here are pictures of the process…..

First Tricia sewed strips of canvas for the base velcro and velcro flaps:
At each corner, she sewed a tab where shock cord can be run through to anchor the panel to the canvas:
This is how it looks installed on the bimini frame:
Here is the back of the panel:
And the final installation:
There is a Morningstar Tristar 30 MPPT controller that controls the charge power to the batteries. This is the remote meter that shows how much amperage is being generated:

The total cost of the system is around $2,600. I’ll report later on how much power we are seeing on average. If you want more information or detail, just leave a comment or email me.

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