value of "tilting" solar pannels

[kevinnem]

So I am looking to insall a set of solar panels off the back of the boat (26x).

I am questioning the value of adding some tilting functionality to them.
Firstly, I live in the north, about 51 latitude. and that means a "land based" panel would be tiled at 40 degrees to start with. with a boat that is healing over maybe 10 degrees (wobbling all the time, and that might help or hurt); I would quickly be getting only 50% of the sun power on them, and that is if the sun is on beam, if it is behind, or in front -- more issues.

The question is , should I look in to a way of being able to tilt the Pannels left right, and fore/aft, to compensate ( at least partly) for this issue?

If the sun is mostly ahead of me, I would think that there would be so much shade from sails that it is not worth consideration, but what if I am on engine power, or just at anchor , hanging out for lunch or something?

if wind blows mostly horizontally across the water, and I have the panel off the back of my boat - how much wind would it catch, is it an issue you think?

What are your thoughts? Needless complexity? great way to improve the power on the boat by many % points? Will it make boarding harder, harder to launch, and retrieve?

[mrron_tx]

Kevinim It sound like You are thinking ...actually overthinking.....that solar panels must be aimed directly at the sun to work Yes.... They are at optimum while aimed that way..... but on a boat that underway....unless You install some kind of gyroscopic sun tracking system....they will rarely ,if ever , be directly into the sun. I have My panels mounted on the mast support....level on the trailer.....and even when parked in My shop , with the doors open, they make voltage You might just experiment and see what works best for You Dauntless.

[kadet]

If you sail a long steady course all the time and spend a lot of time docked in the same spot I would say yes the hassle is worth it to get the extra power. As my boat unfortunately spends most of it's time on the trailer in the front yard I installed them for optimal power when sitting there as the variable sailing conditions I sail in did not make it worth the hassle to make it adjustable. For longer trips I have planned for the future I am going to carry some portable folding panels that I will put up while at anchor for some extra power.

While under motor power why do you need solar? Your motor will be making more power than solar can ever match. How long do you anchor for lunch? 1 maybe 2 hours?

So if you have a 100watt panel that can make a maximum of 5 amps in ideal conditions you might get 10 amps out of it instead of 5 at 50% capacity. With a 100amp batter that is only 5% extra. You don't say what motor you have but my E=TEC has 25amps available for battery charging so the drive in and out of the channel to the boat ramp produces twice that amount of power. (I know that is overly simplified but will do for a quick explanation)

So you will need to consider how you use your boat, how much extra electrical power you need and how short you will be to decide whether it is wort the hassle or not. As I only sail for only a couple of days every couple of months with the longest a 2 day overnighter this arrangement works for me it may not for you.

I have an 80 watt panel off the mast crunch tilted at about 25%, obviously it adds to the boats windage but with the bimini high freeboard etc.. I have not noticed any different in the boats windage, it's still bad

[Obelix]

We got an adjustable 100W panel mounted above the mast crutch, but use it in the horizontal position while underway or on the trailer. We tilt it only when appropriate while tied up to a beach or while docked without shore power. I have to agree with Kadet, there is not much difference in windage since we keep the bimini up most of the time.



Obelix

[Sumner]

I have one of the panels, a 40 watt...


http://purplesagetradingpost.com/sumner ... de-33.html

.... that can tilt fore/aft and flat but did it mainly for the winter sun where the trailer is parked and have it tilted up then. The snow doesn't stay on it and it still produces way more than is needed to keep the batteries up when the boat is sitting there.

I wouldn't go through the trouble to do this on the water as it just isn't worth it on the water to be messing with it,

Sumner

============================
Our MacGregor 26-S

Our Endeavour 37

Our Trips to Utah, Idaho, Canada, Florida

Mac-Venture Links

[mastreb]

Tilting mounts get complicated pretty quickly, and if you're looking at it in terms of dollars, you're probably best off to simply get two fixed 100 watt panels rather than one panel that tilts. That way you make the appropriate amount of power even at 50%, and it costs the same or less than a complicated tilt that will be prone to breakage and finger mangling.

Doubling your generation works at all regular boat angles underway too. There's no simple way to keep a panel tilted at the sun while the boat is underway anyway.

[Russ]

Agree with above.

I've never tested the increase in power when perpendicular. I have the panel tilted slightly facing south when in the slip all week. Otherwise, it's flat. No point in trying to get crazy with it.

Right now, it's on the hard and tilted 45 degrees to let snow fall off. I have a 12v fan that runs for several hours each day to keep air moving below.

[Chinook]

I have a pair of flexible 50 watt panels. They're quite compact (about 24"x24" each), and very light weight. I mount one with snaps on the sliding hatch cover, and the other attaches to the top of the dodger with a pair of coarse toothed zippers. When I'm anchored or at a dock, I am able to unzip the dodger mounted panel and rezip it to one side or the other, depending on where the sun is. I can also unsnap the hatch mounted panel and place it outside the dodger if the hatch is closed, or angle it somewhat to one side or another. I can't precisely quantify how much this benefits output, since all I have is a digital voltmeter, and no amp meter. However, when I reposition one or both of the panels, particularly in the morning or evening when sun angle is low, I see a significant jump in the voltage reading on the voltmeter.

[DaveB]

I live in SW Florida, have 2-40 watt panels on bimini and not worth the effort. Best to have twin Trojan 6 volt golf cart batteries for house.
The solar does work with low demands, It will keep my 65 quart Edgestar fridge running 6-8 hrs during the day.This is the most hottest time the frige runs, many set temps at 10 degrees during high solar and shut it down in evening to turn back on at 45 degrees in morning, this is in SW Florida.
I have done this many times at outside temps were 90 degrees, water temps 87 degrees.

Dave

So I am looking to insall a set of solar panels off the back of the boat (26x).

I am questioning the value of adding some tilting functionality to them.
Firstly, I live in the north, about 51 latitude. and that means a "land based" panel would be tiled at 40 degrees to start with. with a boat that is healing over maybe 10 degrees (wobbling all the time, and that might help or hurt); I would quickly be getting only 50% of the sun power on them, and that is if the sun is on beam, if it is behind, or in front -- more issues.

The question is , should I look in to a way of being able to tilt the Pannels left right, and fore/aft, to compensate ( at least partly) for this issue?

If the sun is mostly ahead of me, I would think that there would be so much shade from sails that it is not worth consideration, but what if I am on engine power, or just at anchor , hanging out for lunch or something?

if wind blows mostly horizontally across the water, and I have the panel off the back of my boat - how much wind would it catch, is it an issue you think?

What are your thoughts? Needless complexity? great way to improve the power on the boat by many % points? Will it make boarding harder, harder to launch, and retrieve?

[DaveC426913]

I'm imagining a gimbal mount to keep it level, and a compass to keep it pointed at the sun.

But I'm highly skeptical it would ever work.

[shanker]

I believe there is significant value in having some sort of adjustment on your solar panel. Just from readings on my multi meter, I found that it would be worth the while to come up with something. I'm not an electrical guy but my research and testing told me to pursue something. My Hunter has a spot for the mast crutch that I do not use while sailing. I came up with a simple system that really makes a difference to recharging my batteries. I did have access to a mill and lathe to make my knuckle piece out of aluminum. I had other ideas for the knuckle but with some access to machinery, I went with this plan. The bracket was made on a water jet, again I'm lucky, but it would be very easy to do something much simpler. If anything else this may inspire you to do something.

When I had my Mac I was thinking of using the mast crutch by simply removing the roller at the top and coming up with an attachment there that can easily pivot. Just a little adjustment goes a long way for solar.

My plan always was to upgrade to a larger panel which I have since done. I bought a 40 watt (thanks Sumner) and it works great. It literally takes me 30 seconds to make an adjustment. I can get that morning sun, the afternoon and late in the evening. It stays aft of the boat and out of the way of the cockpit, cabin top and nosey guests . I'm very happy with this mod and it makes a difference.

http://forums.hunter.sailboatowners.com ... ht=shanker

[133bhp]

I have a 10watt on the table top for trickle charging which gives around 400-500 ma more or less any position within reason in summer. Only In short dark winter days I add the other one at the marina, tilted to the sun. which keeps it floating around 12.9v (100a/hr batts). I rotate both down underway and doesn't hinder movement. .

[kevinnem]

Shaker! He I am in Calgary, usually sail out of ghost lake, .. I assume you usually hit up sylvan? We should head out some time.


So I understand that it would be needlessly complicated to have a compass informed system that tracks the sun , that is not what I am trying to do.

I think I will utimaly go one of 2 ways.
A hinge system that allows me to use a port/starboard tilt, .. or a fore/aft --- but not bot at the same time.

Or a simple fore/aft one like is shown a few posts ago, I like that simplicity.

I will keep you advised of how I make it.

Kevin.