How to align Solar Panels?
Updated: Jun 24, 2022
In a solar photovoltaic power system, each panel should ideally track the sun during the day to obtain the maximum possible energy. Unfortunately, this is often too expensive to implement, and most small solar power systems employ fixed panels. The question then becomes as to what direction the panels should be mounted.
Tilt & Azimuth Angle: What Angle Should I Tilt My Solar Panels?
Solar panels should face directly into the sun to optimize their output. This article explains how to find the right tilt and azimuth angle to get the most production out of your array.
Elevation Angle: The vertical tilt of your panels.
Azimuth Angle: The horizontal orientation of your panels in relation to the equator.
Solar panels work best when they face directly into the sun. But that task is complicated by the fact that the sun moves across the sky throughout the day. It also changes the angle in the sky as the seasons change.
So when you build a solar system, the question is: what's the best angle to mount your solar panels to get the most output?
Tilt and Azimuth angles are in relation to the Equator.
Some people will want to set it at one angle and forget it, while others like to go hands-on with their system and make adjustments to optimize output.
Optimal Azimuth Angle for Solar Panels
For best results, your solar panels should face towards the equator. If you live in Northern Hemisphere, face the south. If you live in the Southern Hemisphere, face them north.
Specifically, you should point your panels toward true north as opposed to the reading on your compass, which is magnetic south.
Many people are surprised to learn that their compass isn't completely accurate. That happens because magnetic forces in the Earth's core pull the compass needle away from the true north or true south. Depending on your location, the compass reading can be inaccurate by as much as 25°!
In the Northern Hemisphere:
If the magnetic declination is east (positive), rotate your panels east.
If your magnetic declination is west (negative), rotate your panels west.
In the Southern Hemisphere:
If your magnetic declination is east (positive), rotate your panels west.
If your magnetic declination is west (negative), rotate your panels east.
Two examples to demonstrate the difference:
If you live in San Diego, California your magnetic declination is about 11° east. Since San Diego is in the Northern Hemisphere, start by finding the magnetic south, then adjust 11° to the east.
In contrast: Cochran, Chile also has a magnetic declination of around 11° east. But since you are in the Southern Hemisphere, you want to point your panels north instead. So you would actually make an adjustment of 11° to the west to find the ideal azimuth.
India lies in the Northern Hemisphere
If you live in Hyderabad, Telangana, your magnetic declination is about 0.5° west. Hence, start by finding the magnetic south, and then adjust 0.5° to the west.
If you live in Srinagar, Jammu, and Kashmir, your magnetic declination is about 0.3° east. Hence, start by finding the magnetic south, and then adjust 0.3° to the east.
By performing these adjustments, you will face your panels directly at the equator, maximizing their exposure to sunlight.
Finding the Optimal Tilt for Your Solar Panels
You have a couple of options here: pick one angle and leave it alone, or adjust the tilt a few times per year to optimize seasonal production.
Depending on your preference, here's our advice.
Optimal Tilt Angle (No Adjustments)
If you never want to bother with adjusting your panels, set them at a tilt angle that is equal to your latitude.
To use the above example again, San Diego is located at a latitude of 32.7157°N. You'd be just fine if you set your panels at around 33° and left them untouched.
One wrinkle to consider is changing the tilt slightly to favor summertime or wintertime output. If you spend more money in the summer running the AC, you might want to optimize for summer production. On the other hand, if you end up blasting the heat during harsh winters, you can set your panels to favor winter production.
This matters more for off-grid systems since you store your own power. If you are grid-tied, you most likely want to optimize for summer production, since the utility company will typically give you a credit for any over-production. You will produce more in the summer, and you can collect this credit in the winter months.
To optimize overall production year-round, tilt your panels at your latitude.
To lean toward more production in the summer, tilt your panels at your latitude minus 10-15°.
To lean toward more production in the winter, tilt your panels at your latitude plus 10-15°.
Seasoned Adjustments to Optimal Tilt Angle
If you have an adjustable mount and don't mind tilting your panels manually, you can change the angle a few times a year to get a bit more production from your array.
We should note that this isn't a particularly common choice. Most of our customers simply give themselves a 5-10% cushion in production when sizing their system so they never need to make adjustments.
The main exception is in heavy snow areas. If snow will accumulate on your panels, pole mounts make a lot of sense. You can adjust them to a steeper tilt angle in the winter, which not only improves output but also sheds snow from the face of the panels.
If you are able to adjust the angle of your solar panels a few times a year, here is the adjustment schedule we recommend:
Spring: Tilt the panels to your latitude.
Summer: Tilt the panels to your latitude minus 15°.
Fall: Tilt the panels to your latitude.
Winter: Tilt the panels to your latitude plus 15°.
These are general guidelines, but you may get better results by customizing your adjustment schedule based on your location. For more info, read through solarpaneltilt.com an old-but-still-excellent reference that explains(in great detail) how to tilt your panels to maximize their production.
Data Credits: solarpaneltilt.com / magnetic-declination.com
Image Credits: unboundsolar.com