Panel Orientation

Re: Panel Orientation

It depends on how much power you want and where you life (snow or not).

The PV Calculator Site lets you plug in any angle/orientation you want and check how much power (by month, and over the year) it will generate.

Also, I recommend the companion site with PDF files of the monthly sun and how angle and tracking options affect power output. The Calculator is easier to use, but the PDF files (US only) are easier to understand and also have a 20 year summary of the output variability caused by weather (some places have very large variations, others are quite small).

The "standard" angle is to raise the panel up by your latitude... If you are at North 40 degrees, raise your panel by 40 degrees--and you will maximize your total kWhrs generated through out the whole year.

If, you need more power in the summer months, then drop the panel by ~15 degrees (40-15=25 degrees from horizontal).

If you want more power during the winter, raise the panel by ~15 degrees...

A "poor man's tracker" would be a fixed mount array that you can adjust two to four times a year to reflect the seasonal angle of the sun.

If you have snow, the more vertical you have the panels, the better they will self clear--depending on how windblown/sticky the snow is (panels should be mounted high enough off the ground so that the snow has somewhere to go). If you have a white snow field in front of the panels, the reflected sun will add to your power generation.

For people near the equator--panels would "want to be" flat... However, roughly, if the panels are at less than 15 degrees from horizontal, they no longer are "self cleaning". Leaves and dust/dirt will probably need to be washed off.

If you want to figure out how the angle "off sun" affects your production... You can use sine/cosine to get a first approximation. You will see that cos 10 degrees = 0.984--or less than 2% power loss. Cos 20 degrees (off angle) = 0.94, Cos 30 = 0.87 and so on...

-Bill

Re: Panel Orientation

BBB,

You are very welcome--be aware the "snow" suggestions are based on what I read... I have seen snow 2-3x in my area in the last 50 years.

-Bill "your fair weather moderator" B.