Why Solar Panels Are Tilted?

The sun is a huge nuclear fusion reactor about 93 million miles away from earth. Everyday earth receives energy from the sun which is the equivalent of 200 million 1-million-kilowatt power plants. What’s more, that is only a ½ billionth of the total energy radiated by the sun!

Most of the energy emitted by the sun reaches the earth by way of solar radiation or sunlight in simple terms. Photovoltaic cells or solar panels as they are more commonly known, capture this sunlight and convert it to the electricity we use in our appliances and it is common to see solar panels installed with a tilt.

So, why Solar Panels Are Tilted? Tilt is the angle at which solar panels are placed. Solar panels can be placed flat at a 180° angle on a flat roof. They will still produce electricity. However, this is not the best angle at which to place them.

While some things about solar panels have changed, others have remained constant. Solar panels still do not perform well in shade or extreme temperatures. In this article, we will examine why solar panels are tilted and how that affects their performance.

Do Solar Panels Need to Be Angled?

Solar panels do not need to be angled for them to work. You can place a solar panel flat on the ground and it will generate electricity if it is in direct sunlight.

Solar panels will even produce energy on cloudy days, rain, and when it is snowing. They will produce less since there is less available light, but they will still generate energy. For more on this, check out our post : Do Solar Panels Work on Rainy Days? How To Protect Them!” & “Do Solar Panels Work with Snow on Them?“

The only times when solar panels do not produce energy is at night or when they are shaded. Shading of a solar panel can be by another solar panel close to it or by trees or adjacent buildings.

How Solar Panel Positioning Affects Its Energy Output

The positioning of a solar panel is possibly the most critical factor in determining how much energy it produces. It influences the yield of a solar panel. It is possibly more important than the type of solar panel.

You would not want to select the most efficient solar panel on the market and get your positioning wrong. It will have a poor energy yield compared to using a less efficient solar panel that is positioned correctly. Solar panel positioning is a factor of three things:

1. Siting
2. Orientation
3. Tilt

Siting solar panels

Solar panels need to be located where they will receive continuous direct sunlight. This can be on a roof or the ground. Typically, this is on the roof as it takes up less space. There must be no shade from trees or buildings which can reduce the panel’s exposure to sunlight.

Orienting solar panels

Aside from being in direct sunlight, solar panels also need to face the correct direction. In the northern hemisphere, solar panels that face south have the highest energy yield. South-facing solar panels track more of the sun as it follows a southward path along the horizon.

The tilt of solar panels

Tilt is the angle at which solar panels are placed. Solar panels can be placed flat at a 180° angle on a flat roof. They will still produce electricity. However, this is not the best angle at which to place them.

Does Tilting Solar Panels Help?

Tilting solar panels helps them produce more energy. Solar panels that are placed at a flat 180° angle horizontally or vertically will not receive as much direct sunlight throughout the day compared to solar panels that are tilted at an angle.

For a flat roof, tilting solar panels will help achieve a better energy yield. For an angled roof, tilting is typically not necessary. As the roof is already at an angle further tilting of the solar panels could even decrease the yield. This all depends on the tilt of the roof.

The position of the sun depends on the time of day and the season. In winter the sun is lower in the sky. Solar panels should be at a right angle to the sun.

How Does Angle Affect Solar Panels?

Solar panels that are tilted at an angle receive more direct sunlight than solar panels at a flatter angle. Tilting can help them achieve the optimum angle that will help them get more sun exposure for longer.

To get the most energy from a solar panel, you need to position, orient, and tilt them where they will capture the most sun. While tilt is not as critical as position or orientation, it is still an important factor for getting the most out of a solar panel.

Tilt and orientation is the reason why we have solar panel tracking systems. In these systems, the solar panels are not permanently fixed in one orientation or tilt. Rather the solar panels swivel and tilt to follow the sun as it moves through the sky. A tracking system can generate between 10 and 40% more energy than a fixed system. (Source)

Why Does the Tilt of A Solar Panel Need to Be Adjusted?

The tilt of a solar panel needs to be adjusted to provide the right angle that will yield the most energy from a solar panel. As the sun is not static but moves through the sky, adjusting to compensate for this ensures improved energy output in a solar panel.

A popular rule of thumb for solar panels is they should be more vertical during winter to compensate for the low angle of the sun in winter and more tilted in summer.

Here’s a simple method to work out the optimum tilt of a solar panel. In winter add 15° to your latitude. Someone in California for example would add 15° to 37° to get a tilt of 52°. In summer, the same person would find their optimum tilt by subtracting 15° from their latitude (37°) to get 19°. (Source)

Tilting solar panels in this way can add a new maintenance component to a solar system compared to having them permanently fixed in position. It is much simpler to just set them and forget them. A simple solution to this is to have them optimally positioned for winter when output will be lower.

While this means you will get less energy in summer than if you adjusted them again for the summer months, it will still improve your overall yield.