solar panels

[john churchill]

i am thinking of putting a panel on my boat. i have found a United Solar model US32 panel that will fit. will 32 watts be enough to keep the batteries topped up while running cabin lights and either nav lites or the anchor lite? other than that my power needs are minimal. any installation tips? i am planning on putting it on the stern rail.



jchurchill@erols.com

[Tom]

i am thinking of putting a panel on my boat. i have found a United Solar model US32 panel that will fit. will 32 watts be enough to keep the batteries topped up while running cabin lights and either nav lites or the anchor lite? other than that my power needs are minimal. any installation tips? i am planning on putting it on the stern rail.

Keeping batteries "topped up" isn't the way to think of it. During the night hours when you'd be running nav lights or an anchor light the solar panel won't be putting out anything, thus your house battery will run down. The next day when the sun comes up and you shut the lights off the panel will start replacing the energy used. Most nav and anchor lights have a 35 watt bulb. During the night while they are on they will withdraw 35 watts per hour from your battery. The next day your solar panel will replace the energy at 32 watts per hour. Your battery will come back during the day and by the next night will be almost topped up. Of course if you use cabin lights, leave the VHF on, run the auto pilot or the cassette player etc., you won't be able to replace the energy used in one daytime cycle. Most of us find that we have to run the engine a little bit also to help out.

Depending on what you have,the alternator can put out maybe 20 amps or more -- which is 240 watts per hour which is about 10 times what your solar panel will provide, so a little kick from the engine helps make up the deficit. When I'm cuising I run the engine for a half an hour each morning while I'm getting the anchor up. That's when the battery is at its maximum drain so the alternator really puts out and helps replace the energy you've used during the night. I think yu'll be pleased with how well the panel works.

As far as installation goes I've been tld you should locate it where no shadow falls across the panel thwartships. The shadow interrupts the flow of electricity so I've been told. Lengthwise a shadow isn't as important. As far as mounting goes I used a pair of rail clamps from west marine. They fit your rail and have a thumbscrew at one end to that yu can tighten or loosen them. To them I attached a piece of L shaped do it yourself aluminum the width of the panel. I set the panel inside the L and screwed through the aluminum into the end of the solar panel. It's worked well and I can tilt it to receive maximum sun. Consider also putting a regulator between it and the battery so you don't over charge the battery by accident.



TacCambria@thegrid.net

[shaft]

John,
Be sure to install a rectifier (if it isn't built into the solar panel) or else you will discover the "discharge after dark syndrome".
Best wishes. Hope to see you this Groundhog Extravaganza.
MRB



thebobers@erols.com