I recently got an ODay 22, complete with a rat's nest of remnants of an old electrical system that I'll remove completely -starting again from scratch. While I intend to use this boat primarily for daysailing, I'd still like to have power onboard for VHF, GPS/nav, running/anchor/cabin lights if needed, etc. My outboard has no alternator hookup, and I'm on a mooring (no A/C access), so I've got to rely on a solar or wind system as my only power source. Since I'm a complete newbie at 12V marine wiring, I just picked up Don Casey's "Sailboat Electrics Simplified" book. It does talk about solar somewhat, but flavors it as a secondary charging source. After reading it I'm still not clear of exactly what I need to do (admittedly I'm a little slow on the uptake!) Does anyone know of any websites or articles that talk specifically about wiring small sailboats using only solar as their power source? Anyone with info or advice to share? I'm in the "research" mode right now, trying to learn all I can. I want to assemble a solid game plan before I start laying out cash for solar cells, appropriate batteries, etc.
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Some more reading.
Check out the site in the Related Link Ed. I think solar would be an excellent source of power. But only if you have enough battery capacity to last between charges. And with a small boat there may not be room for either one, enough batteries or enough solar panels. Do you have any opportunity to get to shorepower, ever? I think you would want a good battery charger for that occasional time when you can "plug in". An outboard with an alternator is probably something to add to your upgrade list. You will get a lot more good advice from this group than I can provide. Good luck.
Check out the site in the Related Link Ed. I think solar would be an excellent source of power. But only if you have enough battery capacity to last between charges. And with a small boat there may not be room for either one, enough batteries or enough solar panels. Do you have any opportunity to get to shorepower, ever? I think you would want a good battery charger for that occasional time when you can "plug in". An outboard with an alternator is probably something to add to your upgrade list. You will get a lot more good advice from this group than I can provide. Good luck.
Another Good Source
is Ample Power. See link. Their two books, Living on, and Wiring for Ample Power are very good to explain what you're looking for. If you do an energy budget, you'll know how much battery capacity you will need, and then how many batteries and how big. Finally, you size your solar array to handle that load on the batteries that you take out on any given day. A good source for energy budgets is West marine Advisor (westmarine.com).
is Ample Power. See link. Their two books, Living on, and Wiring for Ample Power are very good to explain what you're looking for. If you do an energy budget, you'll know how much battery capacity you will need, and then how many batteries and how big. Finally, you size your solar array to handle that load on the batteries that you take out on any given day. A good source for energy budgets is West marine Advisor (westmarine.com).
Solar Panel Setup
Under the "info to share" heading, one of the most difficult problems to deal with is where to place the solar panels. An easy solution is to hang them from the edge of the boat just forward of the pushpit. From the last stanchion to the pushpit put a 1" dia stainless pipe where the top lifeline was. Get a long and slender panel and attach it from the pipe so it can swing up horizontal or fold down out of the way along side the lifelines. The hinges can be made out of plastic with a 1" hole and screwed to the long side of the panels frame. Use a small rod or stick to hold the panel up in the horizontal position when in use. Two large panels, one port and one starboard, can provide a lot of quiet and efficient power.
Under the "info to share" heading, one of the most difficult problems to deal with is where to place the solar panels. An easy solution is to hang them from the edge of the boat just forward of the pushpit. From the last stanchion to the pushpit put a 1" dia stainless pipe where the top lifeline was. Get a long and slender panel and attach it from the pipe so it can swing up horizontal or fold down out of the way along side the lifelines. The hinges can be made out of plastic with a 1" hole and screwed to the long side of the panels frame. Use a small rod or stick to hold the panel up in the horizontal position when in use. Two large panels, one port and one starboard, can provide a lot of quiet and efficient power.
solar power
Ed; Will you be using 12V refridgeration, for more than a couple of days? If so, you'll need a lot of power, maybe more than solar can provide. If you use ice, your energy needs are greatly reduced. Do an energy audit. You may find a small Honda generator hooked to a single large battery will suffice. Good luck.
Ed; Will you be using 12V refridgeration, for more than a couple of days? If so, you'll need a lot of power, maybe more than solar can provide. If you use ice, your energy needs are greatly reduced. Do an energy audit. You may find a small Honda generator hooked to a single large battery will suffice. Good luck.
You Don't Need Much
Your electrical needs should be quite minimal. My nephew has a Cape Dory 25 and uses a flexible solar panel 10" x 20" (0.3 Amp) to charge his battery and works well for him. I also designed the electrical system for AMERICAN STAR a trans Atlantic 23' row boat with 70 W solar panel to charge 2 32 AH batteries. Daily needs were 14 AH with 11 AH to make water - needed every day for the 60 - 90 day race across the ocean. System was designed with no factor of safety due to weight and space limitaions. Worked just fine. To size the solar panel and battery you will need to determine what you think could be the most you might use in a day in amp hours -and select a battery at least 5 times or so daily needs. Can assume a solar panel will produce rated output times 4 hours per day (allows for cloudy days and less than optimum angle to the sun). FOR EXAMPLE Using a 0.3 amp solar panel you would have 0.3 A x 4 hours = 1.2 AH per day average. In any one day you might run lights, VHF, GPS and use 8 AH. In this case the battery capacity would be 40 AH and would be fully recharged in less than a week. Consider putting two batteries on board and only install one - the other on board just in case. If the primary battery went dead - hook up the other and recharge primary at home. Also a lantern for cabin light - gives light, helps keep things dry and doesn't use electrical power.
Your electrical needs should be quite minimal. My nephew has a Cape Dory 25 and uses a flexible solar panel 10" x 20" (0.3 Amp) to charge his battery and works well for him. I also designed the electrical system for AMERICAN STAR a trans Atlantic 23' row boat with 70 W solar panel to charge 2 32 AH batteries. Daily needs were 14 AH with 11 AH to make water - needed every day for the 60 - 90 day race across the ocean. System was designed with no factor of safety due to weight and space limitaions. Worked just fine. To size the solar panel and battery you will need to determine what you think could be the most you might use in a day in amp hours -and select a battery at least 5 times or so daily needs. Can assume a solar panel will produce rated output times 4 hours per day (allows for cloudy days and less than optimum angle to the sun). FOR EXAMPLE Using a 0.3 amp solar panel you would have 0.3 A x 4 hours = 1.2 AH per day average. In any one day you might run lights, VHF, GPS and use 8 AH. In this case the battery capacity would be 40 AH and would be fully recharged in less than a week. Consider putting two batteries on board and only install one - the other on board just in case. If the primary battery went dead - hook up the other and recharge primary at home. Also a lantern for cabin light - gives light, helps keep things dry and doesn't use electrical power.
Same problem witg O'Day Mariner
Ed: My previous boat was a 19 ft. O'Day Mariner without any electrical system. I purchased a Honda outboard 8 hp with a built in alternator. I bought a deep cell battery and installed it forward of the porta-potty. I also installed a voltage gauge in order to see if my battery was being charged. I purchased a small portable solar panel from the local marine supply (around $30) and I would connect it to the battery during the week. When running at night the battery would take care of my running lights and my mast lights . It would also take care of my vhs radio and any other electrical demands. If I saw the gauge showing less volts, I would start my outboard and recharge the battery. This type of system works very well with a small demand. I wish you luck.
Ed: My previous boat was a 19 ft. O'Day Mariner without any electrical system. I purchased a Honda outboard 8 hp with a built in alternator. I bought a deep cell battery and installed it forward of the porta-potty. I also installed a voltage gauge in order to see if my battery was being charged. I purchased a small portable solar panel from the local marine supply (around $30) and I would connect it to the battery during the week. When running at night the battery would take care of my running lights and my mast lights . It would also take care of my vhs radio and any other electrical demands. If I saw the gauge showing less volts, I would start my outboard and recharge the battery. This type of system works very well with a small demand. I wish you luck.
Keep it Simple
Your needs sound similar to mine on a Cat 22 where I get by nicely with a 10 amp flexible solar cell which I connect intermittently as needed to keep above 12v on the deep cycle battery. As Ed S. suggests, you could also pull out the battery once in a while and charge on shore (like in your garage) with a small charger. If you store the boat or leave it on mooring for a few months unattended, this would also be an option, or you might want to leave it attached on the boat to a very small trickle solar cell. Dick
Your needs sound similar to mine on a Cat 22 where I get by nicely with a 10 amp flexible solar cell which I connect intermittently as needed to keep above 12v on the deep cycle battery. As Ed S. suggests, you could also pull out the battery once in a while and charge on shore (like in your garage) with a small charger. If you store the boat or leave it on mooring for a few months unattended, this would also be an option, or you might want to leave it attached on the boat to a very small trickle solar cell. Dick
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