Solar Panel

[Capt Sully]

Not sure if I want to do this, will cost around $700.00 for everything. Solar Panel rated at 85 watts with 40 Amp hrs. would like your views on this ? I'm thinking the 40 watts of power would be 40 watts produced for the day, guess the question on this would be just how much I would be using at a given time ? Just wonder what good this would do and what I could do with 40 amps ? Charging the battery bank would be one, and maybe the only thing ? never used one so I know nothing about them.

[kmclemore]

I have just that panel, and yes, it is helpful for charging the batteries... helps me to keep up with my fridge and nighttime usage of the lights. Having said that, it will hardly ever really produce those 40W... that's under optimal conditions - i.e. pointed directly at bright sunshine with no obstructions. So, unless you're willing to constantly tilt this puppy and move the boat around so it's facing properly, you're not gonna get those 40W... you'll probably get around half. All the same, just sitting face up you'll get a significant amount of energy from it, and it can be useful as an additional source of power, particularly on longer stays.

You'll need:
- the panel... Kyocera makes the best, I am told, and that's what I have.
- a mounting capability - lots of folks use the back rails, but I mounted mine to the slider, though it is blocked by the sails sometimes
- a charge controller (I used a Morningstar SunGuard SG-4, 4.5A controller)... works great, and prevents the batteries back-feeding through the panel at night.

[Hamin' X]

First, it is not 40 amp hrs, it would be 40 amps/12 hrs. That is assuming that you can keep the panel in full sunlight of midday strength and perfectly aligned at all times. Ain't gonna happen. Figure that you might get 50% of the manufacturer's rating.

~Rich

On Edit: Agree with Kevin.

[kmclemore]

And BTW, you can do this for a *LOT* less than $700.

43W Kyocera panel: $209.50
Morningstar Controller: $29.00
Mounting (estimate*): $100.00
Wiring: $15.00

Total: $353.50

That's half of your $700... so you have an extra $346.50 to go towards a nice Engel fridge!

(*That's if you make up a rail-mount... my mounting only took a few screws and some nylon bushings - about $6!)

[c130king]

Kevin,

Assuming the solar panel set-up in your previous post, what battery capacity would be appropriate to run a refrigerator? Would you need more than 2 x Group 24?

Thanks,
Jim

[Russ]

Is it a problem mounted on the main hatch? That is, would accidentally stepping on it destroy the panel?
I slide the hatch forward when working on deck and stand on it often, but I like the simplicity and neatness of this mounting.

--Russ

[kmclemore]

Is it a problem mounted on the main hatch? That is, would accidentally stepping on it destroy the panel?
I slide the hatch forward when working on deck and stand on it often, but I like the simplicity and neatness of this mounting.

--Russ

No, Russ, it's not a problem. First, there's still room on either side of the panel (fore and aft) to step over/around it, as you can probably see in the pics. Second, though I do not recommend it, my panel has been strong enough for me to stand on it very briefly (and usually by accident!)... I weigh 190lbs.

I used an old coiled hair-dryer power cord to connect the panel to the boat, thereby eliminating the problem of having a long, hanging wire up there. Attached at the forward edge of the hatch, it mostly rests up on the deck, just under the front edge of the hatch when closed. When the hatch is open, it stretches forward.

[flynfol]

Hi All,

I have been powering my off grid vacation home with solar for the past ten years. I thought about a solar panel for my Mac 25 ,but for my money decided on a 1000w inverter style generator(Honda). They are QUIET, lightweight and sip gas and I can take it out and use it elsewhere. I have an Iota battery charger that charges quickly(but not too quickly when on shore power and should work well with the Honda. Here in the midwest, we have these things called clouds and really bite into the solar output(unless it is edge of cloud). Using solar for keeping your battery charged while away......that would work well assuming no big load on the battery. An 80 watt panel will give you a little over 4 amps in the summer, in bright sun on average from 10 until 2. The panels lose alot of power when they get hot........in the sun My 500 watt array makes the best power this time of year on a clear day with cold wind blowing on the panels ( I do use mppt charge control which helps in the morning and late afternoon) but if you are depending on the output, you better have a plan B. Running the outboard for power is a big waste of gas, unless you have some high output alternator( check out Sumners mini genset). $700 seems a tad high for 80 watts, but then again 10 years ago, solar was about $2.75/watt. These panels are only made out of thin glass with the cells sealed from the back by a sheet of plastic......I wouldn't recommend standing on them AT ALL.(would you stand on your window?) There are some really good tutorials on solar at arizona wind and sun website (no connections) that can answer you questions. Don't get me wrong, I love solar power, but don't have the room on board for an array that I would need and can't count on sunny days.

Fairwinds, John

[Duane Dunn, Allegro]

Ideally, the hatch is not a good location for a solar panel. I would think it's output would be degraded quite a bit by shadowing. It doesn't take a big shadow to reduce the output. Each of the cells in a solar panel produces a small amount of voltage. Groups of these cells are wired up in series to get to the usual ~14v output for charging. These groups are in turn wired in parallel to get to the full panel output desired. Even a small shadow of a line or wire will take the cells it crosses out of action reducing the output of the whole group below charging voltage and dropping the panel output. The hatch location is subject to all kinds of small and large shadows throughout the day and would rarely be at full output. You are far better off to locate the panel somewhere around the perimeter of the boat, ideally at the ends, and high so it is as shadow free throughout the day as possible. Even better is to have a mount that can be easily tilted to you can get the panel aimed at the sun as directly as possible. On our small boats, probably the best place is up on some sort of support high over the transom.

[Sumner]

Put the biggest panel you can mount and have money for. You can get a .....

http://www.solarblvd.com/product_info.p ... Panel.html

......40 watt from the guys in the link above for $135.00 I've dealt with them twice now and I'm happy.

They also have the controllers. I bought the 4.5 amp......

http://www.solarblvd.com/product_info.p ... oller.html

.................. and recently the 10 amp.......

http://www.solarblvd.com/product_info.p ... oller.html

....... morning star. If you think you might add to the system in the future get a bigger controller now, so you don't spend money twice like I have. I talked to morning star and they said to look at the short circuit amps on the panel or panels and add those up to size the controller.

I recently bought an 80 watt.....

http://www.solarblvd.com/product_info.p ... Panel.html

....... from them for $227 and if I can figure where to put it, maybe on the hatch I'll get another 40 or a 60.

I'm planning on mounting the 80 where.....



....the 40 is now and move it over the ......



....generator. As mentioned above the........



.......................... generator is our ace in the hole.

Jim on the battery question for the frig I'm not sure if I understand it or not, but more batteries are of course better to get you through periods of not charging, but if you can never catch back up with the demand (frig and other electrical devices) with your supply (panels or other means to charge) you will finally lose the war. I think what it all comes down to is how long will you be out. We take few trips, but are out for long periods of time and need to be able to totally replenish the batteries at some point, hence the generator. One last thing on the frig, make sure it is a real compressor type frig like has been mentioned in the "cooler post" on here if you are going to be out more than a day or so.

The best of luck,

Sum

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[Duane Dunn, Allegro]

I think in many cases our boats would be better off with a small 12v generator like the one Sumner made above. Small 120v generators put out very little 12v DC current and making 120v to supply a charger which converts it to 12v is inefficient.

While they are hard to find, I have located few sources for small direct 12v generators. If you know of any others I'd be very interested as I have a special little project I am working on for the boat.

1. My favorite
http://www.altenbatterychargers.com/bat ... ineup.html

They even have diesel versions
A key thing about these versions is they have both a bulk and a float voltage level. If you are going to run high current things (like I am planning to do) off them you can select the lower float voltage and simply use them like a battery.
This is the US distributor of the Christie Engineering product
http://www.christieengineering.com.au/

2.
http://www.epowerchargerboosters.com/page2.html


3.
http://www.batteriesareus.com/index.php ... ts_id=6730

[flynfol]

Iota makes switching type chargers which are quite efficient.( and because they are switch type , are more tolerant of lower A/C input voltage) They range in output up 100 amps... maybe more. You have to size them according to your battery capacity or risk battery damage from excessive charge current. The one I have on board is 30 amps and has smart charging built in(3 stage) and is just about right for a 105 amp/hr battery (when you include other things that are being operated on board). I do have 2 batteries which are switchable. I would love to have solar panels charging my batteries(QUIET is the word), but with 4 of us aboard it is not going to happen. They would have to hang off the stern. Placing a solar panel in anything but direct sun decreases its output tremendously(including small shadows). Are you adjusting the angle while on the hook? while tacking?

I dislike hearing running engines while sailing or anchored, and the Honda 1000 is the quietest running generator I have ever heard(not heard:) ). Any of those generators above produce alot of noise.

I built a Briggs powered alternator years ago as a plan C for my cabin and built a voltage regulator from a schematic from a website(my minor in college was electronics/avionics) which works wonderfully. You can control voltage and current output from an externally excited alternator. You can put alot of hurt on a battery by slamming 100 amps into it if your alternator and engine are capable and your battery is discharged.

Fairwinds.....and sunny skies,
John

[Russ]

Well, I ordered an 80w solar panel (and controller) and I'm trying to figure out where/how to mount it.

I really like the hatch idea (if it would even fit), but I'm afraid I'll either break it or trip on it. But it would be easy to mount.

Reading all the comments above, I think some sort of bracket off the aft mast support is the way to go. While in the slip (most of the week) the stern of the boat is facing South and I could tilt the bracket to achieve a better angle.

Now I just needs Sumner's fabrication skills to come up with a bracket to attach to the mast support.

--Russ

[Sumner]

.......... Placing a solar panel in anything but direct sun decreases its output tremendously(including small shadows). ...........Fairwinds.....and sunny skies, John

Hi John, yes, no matter where you place the panel it probably isn't going to be optimal, but it will help. By adding the 40 watt panel we went from running the generator about 40-50 minutes a day to 10-20 and sometimes even skipping days.

........I dislike hearing running engines while sailing or anchored, and the Honda 1000 is the quietest running generator I have ever heard(not heard:) ). Any of those generators above produce alot of noise........

We usually aren't near anyone and if we were I'd be very careful about running ours. Still saying that it is almost impossible to hear from over 100 feet away and quite comfortable sitting next to it with the exhaust going down near the water. Still I might try my hand a muffler making. The one that came on the Honda is quite good, but it isn't as quiet as their small generators. Yet the small generators aren't putting out 5 HP and can't charge a battery at any where near the amperage as the alternator can on ours. If we think we are going to be near anyone at night we charge while sailing and sometimes do it then anyway.

The real noise with ours comes from vibrations. These boats are like really big drums and sitting in the cockpit with the generator running is not that bad, but the noise from the vibration down below is bad. I'm going to try changing the mounts and see if that helps. Still the solar panel is a lot easier on the ears .

..........I built a Briggs powered alternator years ago as a plan C for my cabin and built a voltage regulator from a schematic from a website(my minor in college was electronics/avionics) which works wonderfully. You can control voltage and current output from an externally excited alternator. You can put alot of hurt on a battery by slamming 100 amps into it if your alternator and engine are capable and your battery is discharged.....

This site...............

http://homepower.com/files/webextras/mark8.pdf

..... has a couple plans for making field controllers to do what you are talking about. I've considered making one, but don't really know if I would gain much in our situation where we only need to run the generator 15 minutes a day or so now. I'll see what happens with the new frig and computer/chartplotter. If I think it might help I might go that way, but like you said "you can put a lot of hurt on a battery" and I don't want to have to monitor it the whole time it is running.

Things are working pretty good now and hopefully better with more panels. Thanks for reminding me about the charge regulator . I think there is no one good answer to this question as the way we use even the same model boat is so different,

Sum

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[kmclemore]

I also have a Honda 1000 generator on board, to supplement the panel. The Honda puts out about 8 amps at 12v (96watts). It is indeed quiet, but as noted does produce vibration if placed on deck. I solved the vibration problem by suspending it on bungees... they go down from the bow pulpit, through the generator's carrying handle, and back up the the pulpit... works a treat. The generator stores nicely under the cockpit's aft seat.