Tilt & Azimuth Angle: What Angle Should I Tilt My Solar Panels?
The “tilt angle” or “elevation angle” describes the vertical angle of your solar panels. “Azimuth angle” is their horizontal facing in relation to the Equator.
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.
Welcome to another entry in our ongoing Solar 101 series. Today we’re going to explain how to mount your solar panels to get the most energy from them.
Let’s start with two key terms: elevation angle and azimuth angle (commonly shortened to “angle” and “azimuth” for brevity).
- Elevation Angle: The vertical tilt of your panels.
- Azimuth Angle: The horizontal orientation of your panels (in relation to the equator, in this case).
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 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?
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.
You can also buy a tracker, which automatically follows the sun’s position in the sky to squeeze the most output from your panels. But trackers are rarely the most cost-effective option. It’s almost always cheaper to buy a few more panels instead of investing in a tracker.
Optimal Azimuth Angle For Solar Panels
For best results, your solar panels should face toward the equator. If you live in the Northern Hemisphere, face them south. If you live in the Southern Hemisphere, face them north.
(Since we’re an American company, the following example assumes you’ll point your system to the south.)
Specifically, you should point your panels toward true south 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 true north or true south. Depending on your location, the compass reading can be inaccurate by as much as 25°!
The difference between magnetic north (the reading on your compass) and true north is known as magnetic declination. This is a measurement of how many degrees you need to compensate from your compass reading to find true north.
A positive number represents eastern declination, meaning true north is east of your compass reading. A negative number represents western declination, meaning true north is west of your compass reading.
So how do you calculate the ideal azimuth angle for your panels?
First, find your magnetic declination from one of the many charts online, or from a tool like NOAA.gov’s calculator.
Adjust the facing of your panels by the magnetic declination value in your location. The direction you adjust the panels depends on where you live:
In the Northern Hemisphere:
- If your 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 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 11° to the west to find the ideal azimuth.
By performing these adjustments, you will face your panels directly at the equator, maximizing their exposure to sunlight (and by extension, the amount of solar power you generate).
Finding the Optimal Tilt For Your Solar Panels
The other half of the equation is finding the vertical angle, or tilt, of your solar panels.
You have a couple 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 A/C, 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 on 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°.
Seasonal 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 a 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.
Related Product: General Specialties 10x Pole Mount
If you are able to adjust the angle of your solar panels a few times per 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.
A Note About Trackers
Trackers automatically adjust your system so that your panels always face directly at the sun. The concept is to squeeze as much production as possible out of your panels.
While the idea sounds great in theory, trackers rarely make sense in residential systems. Tracking equipment costs $600-$1000 per panel, and you could expect that investment to net you 60 to 90 watts of extra production out of a 300W panel.
Alternatively, if you need more output, you can simply add another 300W panel for around $160. If you have the space, it’s far cheaper to add more panels.
The math changes for commercial systems, but in general, most people don’t need trackers. Read the full explanation here.
In the end, you don’t really need to be concerned about fine-tuning your system unless you’re in danger of running out of space to build it. Trackers are often too expensive, and frankly, adjusting panels is going to feel like a chore unless you really enjoy the hands-on DIY approach.
If you have plenty of space, we recommend giving yourself a cushion by adding a few extra panels. The convenience is well worth it.
For more information, check out our free solar racking guide.