How To Find the Best Angle for Solar Panels

Photovoltaic (PV) modules generate more electricity when their orientation and tilt angle maximizes the direct sunlight reaching the panel’s surface. Monocrystalline solar panels with a high-efficiency rating achieve the highest electricity output per square foot.

However, inadequate placement will keep your panels from operating at peak performance. Solar panels of modest efficiency can often generate more electricity at an optimal tilt angle than top-tier solar panels facing the wrong direction. Several factors determine the optimal tilt angle for residential solar power systems:

• Geographic location: Solar energy systems should be tilted true south when used in northern hemisphere countries like the U.S., and true north when used in southern hemisphere countries like Australia. These general orientations will maximize the direct sunlight reaching your panel’s PV cells.
• Latitude: The ideal solar panel tilt angle for maximum productivity depends on your latitude. As you move farther north or south, the angle of the sun in the sky is lower. To capture sunlight effectively, solar panels must be tilted more. For example, the optimal angle for a solar panel system in southern Florida is lower than the ideal angle for an equal-sized system in Maine.
• Electricity usage: In some cases, it makes sense to tilt solar panels toward the east or west. Since the sun rises in the east, buildings with high energy consumption in the mornings may have better results with east-facing solar panels. The same applies to west-facing solar panels in buildings with high energy consumption in the afternoon.
• Roof shading: For some properties, the roof area with the best solar panel placement may be shaded by a taller building or trees. Homeowners should use other, unshaded areas if this happens, even if the resulting panel orientation is not optimal.

Finding the best tilt for solar panels in any location is simple, thanks to the World Bank Global Solar Atlas. You can follow the steps below:

1. Go to the World Bank Global Solar Atlas website

Visit the World Bank Global Solar Atlas website to get started.

2. Find your exact location

Using the Global Solar Atlas world map, find the search bar and input your city name, address or coordinates. You can also drag the map around and zoom in on your exact location. When you click on your location, the Global Solar Atlas will display tables with detailed information about local solar resources.

3. Determine the optimum tilt angle for your panels

Once you select a location, the Global Solar Atlas will display a table based on the map data. You want to look for the “optimum tilt angle for PV modules” value. You will notice that two angles are shown in this line:

• The first angle indicates the optimal tilt for your solar panels.
• The second angle is known as the azimuth angle, and it indicates optimal panel orientation — 0° means north, 90° means east, 270° means west and 180° means south.

For example, if the Atlas shows a value of 35° / 180° for your location, it means your solar panels should have a vertical tilt of 35° for maximum productivity, facing south (180°).

As mentioned above, the optimal tilt angle increases as you move farther north or south, which you can visualize with the Atlas. If you click on locations in Florida, you will notice the optimal tilt ranges from 24° to 28°. On the other hand, if you click on location in New York, the optimal tilt will range from around 33° to 37°. The optimal orientation is south in both cases (azimuth angle of 180°), since Florida and New York are in the northern hemisphere.

4. Check the additional information provided

The Global Solar Atlas provides plenty of useful information beyond your optimal solar panel angle. You can also check the specific photovoltaic power output, which shows the annual productivity in kilowatt-hours (kWh) per kilowatt of peak solar panel capacity (kWp).

For example, if your location shows a specific photovoltaic power output of 1,500 kWh/kWp, this tells you that each solar system kilowatt will generate 1,500 kWh per year. In this case, an average 8 kW residential system will generate 12,000 kWh per year (8 kW x 1,500 kWh/kWp). You can then multiply this value by your local electricity tariff for a quick estimate of your annual energy savings, which can help offset the cost of your solar system.

The optimum tilt angle maximizes your year-round electricity production, assuming your solar panels are kept in the same position. However, you can achieve an even higher output by adjusting your solar panel tilt throughout the seasons. The following table summarizes how you can adjust the tilt angle of your solar panels to boost productivity during different times of the year:

The Global Solar Atlas will only display a general tilt angle that maximizes annual energy production, not the optimal tilt angle by month or season. However, the best solar installation companies use simulation software that is capable of generating more detailed information.

Solar panel arrays with an adjustable tilt angle are generally recommended for ground-mounted installations. This feature is also viable for solar systems installed on flat roofs that are easy to access. Adjusting the angle of your solar panels is not recommended on pitched roofs for two main reasons:

• The solar mounting or racking system becomes more complex and expensive.
• Adjusting solar panel tilt angles on a sloped roof can be dangerous.

You can also utilize automatic solar tracking mechanisms, which follow the sun to maximize system productivity. However, these mechanisms have downsides. Utility-scale solar systems with tracking are around 14% more expensive than fixed-angle systems, according to the Solar Energy Industries Association (SEIA). Your maintenance costs will also be higher since your solar PV system now has moving parts subject to mechanical wear.

Automatic solar trackers may be viable for homeowners with very limited roof space for solar panels. Otherwise, the most effective way to increase production is by simply adding more panels to your system.

Solar panels are more productive when you optimize their tilt angle and orientation based on local sun conditions. Thanks to the Global Solar Atlas, you can easily determine the optimal tilt angle for solar panels in any location. However, you must also consider site-specific conditions such as shading and roof space availability.

You can increase the productivity of solar panels by changing their tilt depending on the time of year. For example, you can decrease their tilt angle during summer months when the sun is high in the sky, and increase their tilt during winter months when the sun is closer to the horizon. This is generally recommended for ground-mount or flat roof installations since doing a DIY solar panel adjustment on a sloped roof can be dangerous.