Angle of solar panels

[GordMay]

Originally Posted by colemj

... If I could tilt my panels so that they were normal to the incident of radiation throughout the day, then I am pretty sure I would produce more than 0.6% extra power...
... BTW, I do understand azimuth - but that really isn't relevant on a boat.
Mark

The 0.6% figure is relative to panels fixed at due south. Certainly, tracking arrays can be more productive than fixed (but randomly moving) arrays.
When calculating the types of variations that fixed panels, on a moving boat, would present; the math gets (too) complicated (for me) - hence my suggestion to google azimuth. There are sites that show the math.

[captain58sailin]

I have been thinking about the angles regarding installation of my solar panels, and due to the nature of vessel movements, and my disinterest in moving the panels around every time the vessel changes heading, I am going to stick with flat mount with enough angle to keep the rain running off and be happy with the production as is. My solar panels will be serving a dual purpose, keep the rain off of me when trolling for fish and producing power, I will learn to live within the confines of the power production and be satisfied.

[colemj]

Originally Posted by MarkJ

Its sue as hell not from the west!

In the SW Caribe tropics, we get many weeks of West winds in the summer. And South winds also.

Mark

[colemj]

[QUOTE=GordMay;1742927]the math gets (too) complicated (for me)

The math isn't very difficult:
1. Find the sun
2. Point the panels at it

Repeat every hour or every time the boat moves.

Mark

[captain58sailin]

I'm too lazy.

[MarkJ]

Originally Posted by colemj

In the SW Caribe tropics, we get many weeks of West winds in the summer. And South winds also.

Mark

You mean in Central America?

Just bcause theres one country in the wrld where you get a few months wonky wonds does not mean most trade winds come from weird directions. The come for one direction, essentially, all over the world.
So stop being a pedant!

To the OP, if you can tilt your panels and live abord so you can adjust them diring the day you will find the morning sun and afternoon sun very useful. You just have to work out which way you boat generally points in your given area. If its of no advantage the horozontal is good, but if you can do better han that then do so

[colemj]

Originally Posted by MarkJ

You mean in Central America?

Just bcause theres one country in the wrld where you get a few months wonky wonds does not mean most trade winds come from weird directions. The come for one direction, essentially, all over the world.
So stop being a pedant!

Come on - you said "in the tropics", not in the Eastern Caribbean islands. I'm willing to bet that your part of "the tropics" is actually a minor portion of them, and kind of strange in having mostly East winds all the time.

Even in the Caribbean sea and immediately surrounding tropical waters, your part of it is rather unusual in having constant wind direction.

The OP is in Florida. Florida and the nearby Bahamas certainly do not have East winds as the main direction throughout the year.

Mark

[chuckg5]

Colej
we're in Stuart, florida for 30 years. and East winds are the primary direction. try going to the Bahamas, always need plenty of diesel. in the winter months it does blow more northerly but crossing the gulf stream
becomes a wild ride.... we're sailors, its not suppost tobe easy

[Stu Jackson]

Latitude Tilt!

Isn't that that new guitar garage band?

[roetter]

We have been in The Bahamas and Caribbean for 3 seasons living on solar alone.

For Florida and Bahamas (and Carribean):

Most winds from the east so davits point west. That is pretty constant. Not much swinging around.

In the morning you have shade from the mast and rigging on the panels. Not much to gain from angling as output is marginal.
Towards noon you should have no shade on the panels anymore. Near horizontal is the best you can do or it becomes complicated. But, at afternoon a tilt aft would increase the output.

A simple forward aft tilt would be great. Does not need to be more than from horizontal to 45 degrees aft. If fixed tilt a little bit so rain washes the dust down.

Solar angle to the sun and potential output:

Degrees % Output Potential
90 100
80 98
70 98
60 86
50 76
40 64
30 50

An extra panel brings more than a fancy tilt that may rip off in a storm. I often see boats with one small panel and fancy tilts, but they were set up in the morning and promptly forgotten. In the afternoon they do exactly nothing.

I can tilt our panels (1800W), but it is a pain involving attaching the topping lift to the aft end cross beam and supporting the weight with it. Then unscrewing the aft support posts and repositioning them. I do it maybe twice a season and then only in December or January.

[chuckg5]

1800 watts ! that's a lot of yardage. u on an aircraft carrier?

[seandepagnier]

I mount some flat, and others to pivot. The ones that rotate will get in the way of the side decks when flat, so it's nice to keep them vertical, unless I really need more power.

[chuckg5]

i now see your on a 45' cat. there is a lot of room on those things, even for 1800 watts of panel

[casablanca]

Solar Panels are cheap. Add more and mount them as convenient. Complexity of tilting is unlikely to offset benefits unless you are limited on area. More is better. You can't have too much, provided your solar regulator is suitable.


Bob
CASABLANCA L420 #86

[El Pinguino]

I have designed and patented a driver for a solar tracking array.... it involves a small globe covered with tiny solar panels which determines the optimum altitude and azimuth at any give moment and sends commands via a VLCC ( very large control computer ) to the alt/az motors which set the VHSA ( very heavy solar array ) at the optimum angle at any given moment.

Works a treat...

The downside is that the drive system consumes 50% more power per day than the VHSA produces.

Swing mooring? Mount 'em flat.

I can trim mine manualy along one ( fore and aft ) axis.... works pretty well....