Ideal angle for solar panels in brisbane

What is the impact if the angle of your panels are not ideal?

Are you planning to install rooftop solar panels in Brisbane, Australia? Do you want to reduce your electricity bills? If yes, then it is a great way to save energy and money. However, before you go ahead, it is vital to determine at what angle you should mount your solar panels.

Since the Sun direction changes throughout the day, sun rays must fall on the solar panels perpendicularly to yield the maximum output. If you install your solar panels on a flat roof, the amount of sunlight that reaches the solar panels is less, which reduces the efficiency of solar panels by 20%.

That is why it is essential to determine the optimal tilt angle of solar panels, depending on your property location. However, the efficiency of solar panels varies with the orientation too. According to a study conducted at the University of Queensland, the ideal angle for rooftop solar panels in Brisbane is 26°, facing toward North. At this point, the sun rays fall on the solar panels at 90°, thereby helping you to get the most from your solar panels.

So, if you live in Brisbane or another state of Australia, what is the ideal angle for solar panels on your property? Well, to help you get the top-notch performance from your solar system, here we have done deep research and created this guide. So, let’s check out the things you should know about the tilt of solar panels.

How the tilt angle and orientation of solar panels affect the performance?

The efficiency of solar panels depends on two factors:

  • Optimal Tilt Angle
  • Orientation or azimuthal angle

Optimal Tilt Angle:

The optimal tilt angle of solar panels is the angle from the horizontal surface of the earth. Generally, if your roof’s tilt angle is in between ±10° to ±15° of the latitude angle, you will lose 1 to 1.5% of solar output.

Orientation or azimuthal angle:

Azimuth is the angle that the solar panels are facing with respect to due North. It decides how much sunshine your solar panels will see throughout the day. In Australia, the panels that face in east or west direction produce approx. 15% less energy than the north-facing panels, depending on location of the property.

What should be the ideal angle for solar panels in Brisbane?

Since the angle of solar panels is controlled by tilt angle and orientation, it is vital to consider both factors. Let’s discuss each factor one by one.

Tilt Angle

Usually, the tilt angle is the same as that of the latitude of the location of your property. However, for most Australian Capitals, it is at least 3° less than the latitude angle.

CapitalLatitude (°)Optimal Tilt (°)Increase efficiency (%)
Adelaide35290.37
Brisbane27240.07
Canberra35300.29
Darwin12180.45
Hobart43370.5
Melbourne38320.44
Perth32280.16
Sydney34310.11

While tilt angle plays a vital role in enhancing the solar panel efficiency, it shows less impact than the orientation of your solar panels. So, let’s check out the ideal orientation for solar panels and how it affects performance.

Azimuth Angle

Australia, being in the Southern Hemisphere, experiences the Sun mostly directed from the North. So, the solar panels show maximum efficiency when installed on North-facing roofs.

Generally, in Australia, the PV panels that face east or west produce less efficiency than the north-facing panels. However, if your roof doesn’t have enough space facing directly North, you can try adjusting its azimuth angle towards west or east. So, try to place the panels more toward a north-east or north-west direction to get the maximum output.

Here is a table to tell you how the panel efficiency varies with the orientation for different Capitals of Australia if the roof pitch is 25°.

Orientation / CapitalAdelaideBrisbaneCanberraDarwinHobartMelbournePerthSydney
North99%100%98%100%97%99%99%99%
South69%74%73%82%62%67%70%68%
East84%88%83%94%81%83%83%84%
West86%87%84%92%80%86%86%85%

Does the optimum angle of solar panels differ during winter?

The direction of the Sun varies with the latitude of the place. So, the Sun is at the highest point in summers and lowest in the winter months. That is why the optimum angle of panels may differ in summers and winters. In fact, you may have to adjust the angle of solar panels for all 4-seasons.

There are two methods to find the optimum angle as per the season.

Method-1:

As a general thumb rule, the solar panels should be tilted more during summers and more vertical in winters to maximize efficiency. In other words, the output of solar panels can be increased by adding approximately 15° to a site’s latitude in summers and reducing approximately 15° to a site’s latitude in winters.

Method-2:

Since method-1 may not be ideal for all places, method-2 can give you better results. As per this method, you have to multiply the tilt angle by 0.9 and then add 29° during the winter months.

In order to find the optimum angle by this method for summer months, multiply the latitude angle by 0.9 and then subtract 23.5°. However, for the spring and autumn season, subtract 2.5° from the latitude angle.

Here is a table to tell the optimum tilt of solar panels by month:

MonthJanFebMarchAprilMayJuneJulyAugSepOctNovDec
Tilt Angle12°20°28°36°44°52°44°36°28°20°12°

What if my house has a flat rooftop?

Since the angle of solar panels affects the overall performance of your panels, an ideal roof pitch ensures that your system generates the maximum energy as per your location. In Australia, the standard roof pitch is between 18° to 30°. For solar panel installation, a roof pitch of a minimum of 10° is recommended. So, the installer may install the solar panels at this angle, especially if the rooftop is facing north.

But if you have a flat rooftop and facing east of the west, you only need slight modification in the tilt angle. Sometimes, you may need tilt racks or frameless panels, depending on the location, which will add to the installation cost. On the other hand, if your roof is facing south, your installer will recommend you opt for an alternative solution or install ground-mounted solar panels in brackets.

What happens if your roof is not at the ideal angle?

Ideally, an optimum tilt angle between 10° to 30° is recommended for the solar panel installations, and the orientation should be the north in Australia (in the southern hemisphere). However, even if your roof is not at an ideal angle, you can save your money and leverage the other benefits of solar panels.

You can install the solar panels onto your rooftop, either facing directly east or west & your panels will generate maximum energy of 85%. However, it is always better than nothing. Make sure you hire the best solar system installation company before proceeding with the installation process. 

Related Questions

Do solar panels work on cloudy days?

Since clouds can block around 20% of sunlight, solar panels work on cloudy days. In fact, rain enhances the efficiency of solar panels by clearing the accumulated dust and dirt.

Is morning sun or afternoon sun better for solar panels?

In Australia, the Sun is at its peak when it sits in the sky at midday. So, if you have panels installed facing north, the best time to utilize your solar energy is anywhere between mid-morning to the afternoon.

Do solar panels work in winters?

Since solar panels absorb sunlight and convert photons to electrical energy, they work in winters until the panels are not covered by the snow.

Conclusion

While solar panel installation is increasing day by day, it is an eco-friendly way to save money. However, it is vital to install the solar panels at an accurate angle so that they can capture the maximum amount of sunlight and generate maximum output.

For Australia, the ideal optimum tilt angle is 26° with an orientation towards the north. However, if your rooftop does not have an ideal angle, don’t get disappointed. You can also mount solar panels, but remember that you may have to face a little loss in terms of output and incur the extra cost of tilt racks and brackets.

We hope that this guide has helped you understand the importance of the angle of solar panels. If you have any doubts, feel free to share them with us. We would love to solve your queries.