Simple Solar Question (kinda of a Poll ?)

Ideally, you would adjust your tilt as you track around each day to keep the panel aimed. You need to tilt it higher earlier and later in the day than at noon.

You can work out the correct tilt for noon if you know your latitude and the sun's declination.

I pick an angle tilted up higher than ideal for noon on the tracker, that still gets Isc at noon (you get about a 10 degree allowance anyway), but now it is better for when the sun is lower the rest of the time.

If the panel remains pointed South all day, then leaving it that high for noon will cost you in the shoulder hours. There is an optimum tilt lower than for noon where you get the most AH haul all day.

So: for tracker fixed tilt, tilt it higher than for noon; for tilted only fixed South, tilt it lower than for noon

I don't know if my terminology is the same for us all.
When I say "tracking the sun", I'm talking keeping the sun perpendicular w/ the panels, or maybe better defined as the panels shadow directly behind the dish ?

I doubt that is the same as "tracking w/ fixed tilt"

Is the difference coming into play here ?

From what I have seen, I'm getting double the AH in a day by "tracking the sun", verses laying flat.
When I go south this winter, I doubt I'll see those percentage numbers change by much. But maybe I have much more to learn.

BFL13 wrote:
I did measure my results with the 130w panel (it is all proportional, so you can work it out for your 190w) in May at 49N when tracking was moving it three times a day.

Flat-56AH
Tilted aimed South all day-70AH
Tracking with fixed tilt-90AH

You can see that two of those 56s is 112--more than the 90. But that was in mid-May at 49N

You can't escape the details (the Devil is in the details!)

When the sun is higher you get less difference between tilted and flat. Longer daylight time gives more diff between tracking and not.

With the longer daylight you get more angle the sun goes around where it rises and sets more north of east and west up to 23 degrees more each side in June.

So in March and Sep it is 180 degrees and in June it is 226. Dec gets you only 134. The sun moves around at 15 degrees an hour. (Earth rotation) So June gets you 226/15 = 15hrs, Dec is 134/15 = 9 hrs and Mar or Sep is 180/15= 12 hrs

Tilting is affected by the sun's declination changing that 46 degrees back and forth every six months too. That's 7.7 degrees a month to change your tilt. (about 2 degrees a week)

When you move south for the winter, you get under a higher sun than up north but you still have the shorter days

In summer with more than 180 degrees of sun travel sunrise to sunset, you get the problem that your rig casts a shadow part of the time when the panel is placed on the ground to the south side. This is why I put my first tracker on the roof so it could see all around

Great info' I made another print copy of a BLF post. Keep 'em comin'


O$S

No long drawn out posts....
I find flat mounted 560watts does me good, if I had room would go to 800 watts
It all depends on your location time of year and loads
Never have any time while camping or would even remember to move a portable panel

I did measure my results with the 130w panel (it is all proportional, so you can work it out for your 190w) in May at 49N when tracking was moving it three times a day.

Flat-56AH
Tilted aimed South all day-70AH
Tracking with fixed tilt-90AH

You can see that two of those 56s is 112--more than the 90. But that was in mid-May at 49N

You can't escape the details (the Devil is in the details!)

When the sun is higher you get less difference between tilted and flat. Longer daylight time gives more diff between tracking and not.

With the longer daylight you get more angle the sun goes around where it rises and sets more north of east and west up to 23 degrees more each side in June.

So in March and Sep it is 180 degrees and in June it is 226. Dec gets you only 134. The sun moves around at 15 degrees an hour. (Earth rotation) So June gets you 226/15 = 15hrs, Dec is 134/15 = 9 hrs and Mar or Sep is 180/15= 12 hrs

Tilting is affected by the sun's declination changing that 46 degrees back and forth every six months too. That's 7.7 degrees a month to change your tilt. (about 2 degrees a week)

When you move south for the winter, you get under a higher sun than up north but you still have the shorter days

In summer with more than 180 degrees of sun travel sunrise to sunset, you get the problem that your rig casts a shadow part of the time when the panel is placed on the ground to the south side. This is why I put my first tracker on the roof so it could see all around

This question is unanswerable with the information given. It depends on the season and location. You'll get more further south (where the sun's angle of incidence on the panel is less), and you'll get more during the summer than winter (duh).

From my single 115W panel laying flat on the roof, I've gotten anything from 8 amps (at Assateague in August) to 5 amps (in Northern Ontario in July) to 3 amps (at home in the winter).