Can anyone tell me of a good solar panel for use on sailboat to keep my nav system powered while sailing? Thank You
solar panel
- Thread starter MIKE1009
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Mike what is your power requirement?
Look at the name plates on each piece and add up the "amps" that is the way you can determine what size solar panel you will need. Then you need to determine where you have space for a panel and what size you can make fit. I don't believe that there are any bad systems but there may be some that are better.
Look at the name plates on each piece and add up the "amps" that is the way you can determine what size solar panel you will need. Then you need to determine where you have space for a panel and what size you can make fit. I don't believe that there are any bad systems but there may be some that are better.
You will still need a battery
You can't run boat electronics off a solar panel without a battery because the no load voltage can get too high. As soon as you switch something on - poof! I find a small 5-10 Watt 10 year old panel left out all week keeps my battery fully charged.
You can't run boat electronics off a solar panel without a battery because the no load voltage can get too high. As soon as you switch something on - poof! I find a small 5-10 Watt 10 year old panel left out all week keeps my battery fully charged.
A battery charger is cheaper
As bay sailor said you will still need a battery and unless you are powering an autopilot and radar even a 50 AH (Read car) battery will last quite a long time running just nav equipment. A solar panel is going to be costing like $70 and the auto parts store has chargers for $25.
As bay sailor said you will still need a battery and unless you are powering an autopilot and radar even a 50 AH (Read car) battery will last quite a long time running just nav equipment. A solar panel is going to be costing like $70 and the auto parts store has chargers for $25.
Well Mike...
even though your question is a bit technically incorrect...the issue for you is keeping your battery charged via solar while using your instruments. If you have a 10amp draw from your instruments then you need a panel that can provide 10 amps at 14V (charging voltage) or roughly 140 watts in direct sunlight. Of course this will only provide this amperage while unshaded by your sail and in direct sunlight. Depending on your ACTUAL instrument amperage use you could need more or less. That said...that is NOT a practical way to use solar panels...i.e. for replenishment while underway. What you really need to do is get a battery bank that can STORE the amps you need and then get a solar panel that will keep those batteries topped up when the boat is not in use. Figure about 1/3 of the rated wattage will be the average amp hours per day you will get from a fixed panel to send to your batteries. (100 watts=33 A/H's). First step is figuring out how many A/H's you need to use each weekend...then doubling that to properly size your battery bank.
even though your question is a bit technically incorrect...the issue for you is keeping your battery charged via solar while using your instruments. If you have a 10amp draw from your instruments then you need a panel that can provide 10 amps at 14V (charging voltage) or roughly 140 watts in direct sunlight. Of course this will only provide this amperage while unshaded by your sail and in direct sunlight. Depending on your ACTUAL instrument amperage use you could need more or less. That said...that is NOT a practical way to use solar panels...i.e. for replenishment while underway. What you really need to do is get a battery bank that can STORE the amps you need and then get a solar panel that will keep those batteries topped up when the boat is not in use. Figure about 1/3 of the rated wattage will be the average amp hours per day you will get from a fixed panel to send to your batteries. (100 watts=33 A/H's). First step is figuring out how many A/H's you need to use each weekend...then doubling that to properly size your battery bank.
Wind generators are cost effective however
If you are sailing then there is wind and a wind generator will at least supply some of your power requirements. If you check out the $$/watt wind generators win hands down over solar. Course an alternator is an order of magnitude cheaper still but that would be motor sailing. For the record, a chart plotter, GPS, wind instruments, depth sounder, knot meter and clock will probably be drawing less than 3 amps. If you leave them all on all day and night then you would need a system that supplies 3*24=72 AH every day. If you are using a wind generator then 3 amps is easy as long as the wind is above 10-12 kts. So the only varerable is how big a battery do you need to cover windless days. You might choose to motor then so even that goes away. If you use a solar panel then 3 amps is easy to achieve but you have to collect all 73 AH during the day. So 73 AH / 10 hours = 7.3 Amps average while the sun shines for 10 hours a day. That is 7.3 Amps * 14 Volts = 102 watts solar panel size minimum. Factor in cloudy days and you would be looking at 150 watts. Factor in that it is lying flat and getting shaded for parts of the day and you are starting to see 200 watts. And you still have the battery to get you through the night and cloudy days. It gets fairly complicated as you are designing a system (generator-storage-loads) and all the parts interact in weird ways. What kind of sailing are you planing on doing (day-sail, over-night, cruising)? If you want help designing your system email me at roosaw@verizon.net. I did this for my boat and have some experience as a systems engineer.
If you are sailing then there is wind and a wind generator will at least supply some of your power requirements. If you check out the $$/watt wind generators win hands down over solar. Course an alternator is an order of magnitude cheaper still but that would be motor sailing. For the record, a chart plotter, GPS, wind instruments, depth sounder, knot meter and clock will probably be drawing less than 3 amps. If you leave them all on all day and night then you would need a system that supplies 3*24=72 AH every day. If you are using a wind generator then 3 amps is easy as long as the wind is above 10-12 kts. So the only varerable is how big a battery do you need to cover windless days. You might choose to motor then so even that goes away. If you use a solar panel then 3 amps is easy to achieve but you have to collect all 73 AH during the day. So 73 AH / 10 hours = 7.3 Amps average while the sun shines for 10 hours a day. That is 7.3 Amps * 14 Volts = 102 watts solar panel size minimum. Factor in cloudy days and you would be looking at 150 watts. Factor in that it is lying flat and getting shaded for parts of the day and you are starting to see 200 watts. And you still have the battery to get you through the night and cloudy days. It gets fairly complicated as you are designing a system (generator-storage-loads) and all the parts interact in weird ways. What kind of sailing are you planing on doing (day-sail, over-night, cruising)? If you want help designing your system email me at roosaw@verizon.net. I did this for my boat and have some experience as a systems engineer.
Sun power
I have two 5 watt solar panels (from Canadian Tire) mounted on the top of my 23 Gramp Pop-top. (One might have been enough but i liked the look of two, and i didn't want to run out of "gas"
They have served well to keep my battery charged & on-call for lights, radios, depth sounder, lap-top et al. Can't always plug in a charger. But sun-catchers are always there...
I have two 5 watt solar panels (from Canadian Tire) mounted on the top of my 23 Gramp Pop-top. (One might have been enough but i liked the look of two, and i didn't want to run out of "gas"
They have served well to keep my battery charged & on-call for lights, radios, depth sounder, lap-top et al. Can't always plug in a charger. But sun-catchers are always there...- Status