If you live in the northern hemisphere, you would point your panels due south. If you live in southern hemisphere, your panels should be pointed north. Most homeowners with solar energy systems mount their panels in a fixed position, where the panels can be manually tilted as needed (for example, they can be adjusted seasonally). Here are some ways to calculate the best angle for your solar panels.
Take your latitude and add 15 degrees for the winter, or subtract 15 degrees for the summer.
For example: if your latitude is 40 degrees, the angle you want to tilt your panels in the winter is: 40 + 15 = 55 degrees.
In the summer, it would be: 40 - 15 = 25 degrees.
In the winter months, when there's less sun, take your latitude, multiply it by 0.9, and then add 29 degrees.
For example: if your latitude is 40 degrees, the angle you want to tilt your panels in the winter is: (40 * 0.9) + 29 = 65 degrees.
This is about 10 degrees steeper than the "quick and easy" way! It's also more effective, because you want your panels to be directly facing the sun at mid-day during those short winter days.
Take your latitude, multiply it by 0.9, and subtract 23.5 degrees.
For example: if your latitude is 40 degrees, your panels should be tilted at: (40 * 0.9) - 23.5 = 12.5 degrees.
Take your latitude and subtract 2.5 degrees.
For example: if your latitude is 40 degrees, the best tilt for your panels in the spring & fall is: 40 - 2.5 = 37.5 degrees.
You don't necessarily have to adjust the tilt of your panels every season. If you find that the energy generated by your solar panels is sufficient for your winter energy needs -- assuming that your highest energy usage is in the winter -- you can just leave the panels in the same position.
Note that the fixed-mount solar panels will be at their least efficient during the summer, spring and fall, when the sun moves across a large area of the sky. Panel systems that "track" the position of the sun are more efficient -- but also more costly.
Of course, the correct angle for solar panels is for ideal locations -- but in the real world, we deal with trees & buildings that may shade the panels, or areas with lots of leaves, dust, or debris. You might need to adjust the angle a little bit to compensate for less-than-ideal conditions.
|Summary: Solar Panel Angle Calculation|
|SEASON||ANGLE / TILT CALCULATION|
|Winter||(Latitude * 0.9) + 29 degrees|
|Summer||(Latitude * 0.9) - 23.5 degrees|
|Spring and Fall||Latitude - 2.5 degrees|
Knowing how to figure the correct angle for solar panels can help you to generate the most energy from your solar powered system. Thankfully, there is a device known as a solar tracker that will automatically orient the solar panels towards to the sun to maximize their effectiveness. While it is an additional investment, some people may find that the increase in effectiveness is worth the extra cost.