September 19, 2023

Best Solar Panel Angle: How To Find It — And Does It Matter?

What does “solar panel angle” mean?

Solar panel angle is another way of describing the vertical tilt of your PV system. When a solar system is level with the ground, it has no tilt. If it’s standing upright — perpendicular to the ground — it is at a 90° angle.

The solar panel angle can affect the amount of solar electricity you generate and is based on two factors: latitude and the season.

Optimizing and adjusting your solar panel tilt according to these factors can help you maximize your solar power production.

What is the best solar panel tilt for your latitude?

The angle of tilt increases with latitude — the further your house is from the equator, the higher your tilt angle should be.

For example, in states located at lower latitudes (such as Arizona and Hawaii), the sun is higher in the sky. In these states, solar PV panels require a low tilt to capture direct sunlight.

On the contrary, for states at higher latitudes — like Minnesota and Oregon — the sun is lower in the sky. In those states, solar photovoltaic panels should be installed at higher tilt angles in order to receive maximum sunlight.

Solar panel tilt based on the position of the sun. Image credit: EIA

Optimal tilt angle increases with latitude. Image source: EIA

How can you determine the optimum angle for solar panels for your state?

There’s a simple rule of thumb for calculating the best tilt angle for fixed-mount solar panels. Subtract 15 degrees from the latitude at your location during summer and add 15 degrees to your latitude during winter.

For a precise method, use the second formula on this page to calculate tilt angle.

For instance, in the San Francisco Bay Area, the best solar panel tilt angle is between 22-23 degrees. For Los Angeles, a solar panel tilt of 19 degrees works the best.

These angles will give you the best overall output over the course of the year if you’re going for a fixed installation. It’s actually possible to increase energy production further by adjusting solar panels based on the season - we explain that in the next section.

What is the best solar panel tilt for each season?

The angle of the sun not only changes based on different latitudes, but also with the change of seasons. As shown in the illustration below, the sun is lower during the winter months and higher in summer months.

The sun is lower in the sky during winter. Image source: Lighting Research Center

This means that if you wanted to ensure that your solar panels are always positioned for maximum exposure to sunlight, you would need to adjust them for each season.

The table below shows the optimal solar panel angle for various states in the U.S. during winter, spring/fall, and summer.

Optimum solar panel angles for various U.S. cities

A system at 40° latitude enjoys a significant energy boost of 4.1% if adjusted just twice a year.

An additional two adjustments for spring and fall can yield an additional 0.5% output — see below.

How changing the angle affects solar panel output

 Source: Solar panel tilt

However, adjusting your solar panels four times a year (or even just twice) is not a straightforward task. After all, most solar panels are mounted on the roof’s fixed angle and can’t be adjusted.

The only way to adjust solar panels easily is to utilize a ground-mount system and install axis-tracking solar panels. However, there’s a big downside to this approach: while it does increase solar output, it increases your costs by much more. As a result, solar axis trackers currently aren’t worth the investment.

Now, are you wondering why you still only get 75.7% of optimal output after adjusting for each season? That’s because the remaining amount can only be achieved by adjusting for solar panel direction during the day. 

How does having a shallow vs. steep roof angle affect solar production?

If you compare the output produced by solar panels over a year, you’ll find that there is relatively little difference between the panels installed on a shallow (15 degree) roof and a steep (45 degree) roof.

This is because the different pitches will balance themselves out across seasons. Solar panels on a shallow roof capture more sunlight during the summer season, whereas, solar panels on a steep roof will produce more power during the winter.

While you can use solar panel trackers to keep them at the optimum angle at all times, the costs and complications involved aren’t worth it in most cases.

Therefore, in solar-friendly states like California, most homeowners find solar systems to be worth the investment, whatever angle they are installed at.

This is evidenced by California’s solar statistics, as shown below in this chart by the Energy Information Administration.

Fixed mount solar panel tilts for homes in California Chart. Image source: EIA

Conclusion: Solar panel angle matters, but not that much

The performance of solar panels is affected by their angle of inclination. To extract maximum power from a PV system, you would have to adjust the angle based both on latitude and season.

In real situations, you often have to deal with fixed roof angles where there is no option to adjust or tilt the solar systems.

Because of this, solar systems are installed across a range of tilt angles as a means to accommodate a variety of roof pitches found on homes - effectively saving homeowners money.

The bottom line: The optimal solar panel angle can increase production, but failure to achieve isn’t a dealbreaker.

Read our other posts

Energy-saving tips: energy conservation and energy efficiency

Energy-saving tips: energy conservation and energy efficiency

Are Residential Solar Panels Worthy in 2023?

Are Residential Solar Panels Worthy in 2023?

With the cost of everything rising across the country, millions of American homeowners are asking themselves whether or not it’s finally worth it to install solar panels.The answer to this question depends on a ton of factors, like what your utility charges for electricity and where you live. But, for many Americans, solar panels are definitely worth the investment.Our solar panels cost and savings calculator takes all the guesswork out of figuring out if solar is worth it or not for your specific home. You can either dive straight into our calculator and get an accurate estimate of how much a solar installation can save you, or you can read on to get a closer look at how to determine if solar is worth it for your home.

What You Need to Know Before Adding New Solar Panels to an Existing System

What You Need to Know Before Adding New Solar Panels to an Existing System

Sometimes, you’ll outgrow the original solar system installed on your roof, and you might need to add some more panels to meet your additional electricity needs. Some common reasons to expand your solar panels are getting an electric vehicle, installing a battery, electrifying your home, or making home upgrades like an addition or a new pool.You may not know where to begin if you think you need more solar. Don’t worry - we cover everything you need to know about adding more solar panels to your existing solar system and if it’s always the right choice.