Solar Panel,fixed or flying?

[model 10]

[QUOTE=El Pinguino;2190821]In my experience you need 30 knots before you get really worthwhile output from wind ( 4 amps plus) and in the normal cruising lifestyle as I have known it that is rare. .

I've had 2 different kinds and they were both really going in 20- 25 knots. The newest 400w job shuts down at 35 knots. It's making 4 amps in probably 18 knots. You see a little juice starting to flow in just under 10 knots.

[ramblinrod]

Originally Posted by barnakiel

"...Adjustable panels is a huge waste of time and money...."

With full respect, I will somewhat disagree.

Your solar harvest is dictated by cosine of the sun angle.

You say the sun angle is constantly changing, and this is the whole point behind adjustable panels. So where you see an argument con, many will see an argument pro.

When anchored the boat is not moving thru 360 degrees but more often thru about 60 degrees. So once you adjust the panel, you are reaping extra amps till the sun moves by 30 degrees or so.

Not all boats have the space to place so many horizontal panels that their output will fully charge the bank in one sun-day. Many smaller monohulls can benefit from having adjustable panels.

I respect your view and understand that our opinions must differ simply because our sailing styles/boats are vastly different. (We have a small and narrow ended boat and we only sail either crossings or else we are anchored in the West Indies).

We have 150W of solar panels onboard wired thru an A/Ah/cumm Ah monitor, so every time I adjust the rig I can immediately read the result. Trust me, the difference is of a major grade.

Cheers,
b.

I do not question that aiming a solar panel squarely to the sun will produce more amps. I know it will.

But is it practical?

I suppose if one has the discipline to be changing the adjustment.

I know I don't.

Especially if I consume about 100 A-hrs per day, and the panel, even when adjusted optimally replenishes less than 50% of consumption.

So now the engine driven alternator has to be operated every day for an hour. Be tied to adjusting the panel several times per day and that can be reduced to 55 minutes.

At some point (I suspect usually before the end of the second week), many will stop adjusting and just run the engine a little longer each morning.

[El Pinguino]

Originally Posted by ramblinrod

I do not question that aiming a solar panel squarely to the sun will produce more amps. I know it will.

But is it practical?

I suppose if one has the discipline to be changing the adjustment.

I know I don't.

Especially if I consume about 100 A-hrs per day, and the panel, even when adjusted optimally replenishes less than 50% of consumption.

So now the engine driven alternator has to be operated every day for an hour. Be tied to adjusting the panel several times per day and that can be reduced to 55 minutes.

At some point (I suspect usually before the end of the second week), many will stop adjusting and just run the engine a little longer each morning.

I don't get stressed about it... I don't check the angles...typically I just give the panels a kick in the morning...another one after lunch.
Frinstance.... in my present slip last winter heading NE.... 41 south plus about 20+ north declination.... max altitude of the sun about 30 degrees.... so for mid afternoon say 20 something.... panels just live at about 70* from flat and no adjusting done at all.

[Snowpetrel]

I also prefer movable panels, at least where possible. But if you are in the tropics flat onew probably work fine most of time.

Down here at 42 south in winter tilting makes a huge difference. Especially if you are sailing east or west in a northerly, when with heel a flat panel will hardly put out anything.

[El Pinguino]

Originally Posted by Snowpetrel

But if you are in the tropics flat ones probably work fine most of time.
....

Agreed, esp when you take into consideration the 'at sea/at anchor' ratio of the average tropic bird.

[ramblinrod]

Originally Posted by El Pinguino

I don't get stressed about it... I don't check the angles...typically I just give the panels a kick in the morning...another one after lunch.
Frinstance.... in my present slip last winter heading NE.... 41 south plus about 20+ north declination.... max altitude of the sun about 30 degrees.... so for mid afternoon say 20 something.... panels just live at about 70* from flat and no adjusting done at all.

As I said, in a slip (stationary boat) with no shore power, it may be worthwhile. In a slip with shorepower, no need?

So we've heard from some who say they do adjust panels. I would like to hear from those who have adjustables but rarely/never do. C'mon you're out there, I see it all the time, will ya fess up?

[Paul L]

I generally don't like adjustable panels. They certainly can get you more amps out of your panels if they are set correctly. That's a big if. I can't tell you how many times I've had my morning coffee or evening beer looking at panels adjusted 100% the wrong direction. For me it's another maintainace item and one that gets forgotten too often.