# question about solar panel angles



## budgetprepp-n (Apr 7, 2013)

with a Latitude of 39.09,,,,,,,,64 degrees in the winter,,,,,,,,16 degrees in the summer,,,,,,,is this correct?


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## HuntingHawk (Dec 16, 2012)

I'm at 30 & have to be able to adjust between 15-45 threw the year.


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## HuntingHawk (Dec 16, 2012)

Rule of thumb is you have enough solar to cover needs in the winter. Winter is the least hours of sunlight. Could easily have twice as many hours in the summer for producing electric.

I adjust my panel angles once per month. It just works for me.


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## budgetprepp-n (Apr 7, 2013)

I was using this page to figure my angle for my panels but isn't 16 degrees almost straight up? 
How to Figure the Correct Angle for Solar Panels


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## budgetprepp-n (Apr 7, 2013)

HuntingHawk said:


> I'm at 30 & have to be able to adjust between 15-45 threw the year.


Check out your latitude with the chart in this link and see what you come up with.


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## HuntingHawk (Dec 16, 2012)

Are you using those angles based on the horizon?


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## HuntingHawk (Dec 16, 2012)

budgetprepp-n said:


> I was using this page to figure my angle for my panels but isn't 16 degrees almost straight up?
> How to Figure the Correct Angle for Solar Panels


NO. 16 degrees would almost be flat. Reason is the summer the sun is so far north.


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## HuntingHawk (Dec 16, 2012)

You want one of these to be able to set your angle.

Angle Finder w/ Dial Gauge


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## budgetprepp-n (Apr 7, 2013)

HuntingHawk said:


> NO. 16 degrees would almost be flat. Reason is the summer the sun is so far north.


Yea Ok yes ,, !6 in the summer my panels are almost flat now for summer. The 64 for winter that's sort of steep for winter.


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## HuntingHawk (Dec 16, 2012)

The thing is, on land you can't see the horizon unless you are looking south over a huge body of water.

My suggestion would be to set your oanels at you 40 degrees & have someone ready the amperage to the controller. The start properly setting the angle to what it should be for the time of year. You'll be surprised at the difference. Even if its only 5 or 10amps figure that out over a month.

True horizon is different then the horizon you perceive with your eyes. Kind of like the difference between magnetic & true north.


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## PaulS (Mar 11, 2013)

Basically you take your latitude and add 15 degrees for winter and subtract 15 degrees for summer. Zero degrees is a vertical line (gravity). So at 40 degrees north latitude your range would be 55 degrees from vertical in summer and 25 degrees from vertical in winter. 

If you use 90 degrees as vertical then the summer angle would be 90 - north latitude (40) = 50 -15 = 35 degrees from horizontal
In the winter it would be 90 - north latitude (40) = 50 + 15 = 65 degrees from horizontal. 

It is the same angle in both exercises just measured from 90 degrees apart.


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## budgetprepp-n (Apr 7, 2013)

PaulS said:


> Basically you take your latitude and add 15 degrees for winter and subtract 15 degrees for summer. Zero degrees is a vertical line (gravity). So at 40 degrees north latitude your range would be 55 degrees from vertical in summer and 25 degrees from vertical in winter.
> 
> If you use 90 degrees as vertical then the summer angle would be 90 - north latitude (40) = 50 -15 = 35 degrees from horizontal
> In the winter it would be 90 - north latitude (40) = 50 + 15 = 65 degrees from horizontal.
> ...


SpaulS did you check out that link? look at that because I'm coming up with 16 and 64


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## PaulS (Mar 11, 2013)

As long as you are within +/- 10 degrees it will make only 1% difference in efficiency. The latitude +/- 15 degrees will get you that close.

The axis of the earth tilts 23.5 degrees so you should actually be adding and subtracting 23.5 degrees to/from your latitude for perfect alignment. The advanced formula that is used on the link page accounts for the refraction of the atmosphere as well as the tilt of the earth.

If you feel the need to be as close as is practical then use your latitude plus or minus the 23.5 and it will be very close to perfect alignment on the summer and winter solstice. before and after that three day period it will be further from ideal. You need to move your panels in an arc from -23.5 to plus 23.5 degrees from your latitudinal angle in six months. You want the "middle" of the month to be as far one way as the ends of the month are off the other way. - Unless you will be moving the panels on a weekly basis. You have 47 degrees of movement divided by 6 months which is 7.8 degrees per month. If you set your panels up on the spring or fall equinox then they would be set at your latitudinal angle. They would be in nearly perfect alignment with the sun. Each month toward summer they would be tilted back (so they would face closer to the horizontal) 7.8 degrees. Each month after the summer they would be tilted forward 7.8 degrees (closer to the vertical) until the winter solstice and then they would be tilted back the 7.8 degrees until the summer solstice. At the spring and fall equinox the panels would always be tilted exactly the latitudinal angle.


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## Prepadoodle (May 28, 2013)

Stick a toilet plunger on your panel, wait till around noon, and adjust the angle until the shadow is as short as possible, at least in the up/down direction.

If you aren't going to adjust your angle seasonally, do this in the middle of winter.


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