How Does Location Play a Role in Solar Energy Efficiency?

Solar panel efficiency depends heavily on location. Factors such as elevation, latitude, climate, shading, and panel orientation influence how much sunlight lands on your panels and, therefore, how much energy your system can generate. While those in sunnier regions have an advantage, solar power remains viable in almost all locations with proper planning and set-up.

Whether you’re installing a new system or optimising an existing one, understanding these location-based influences can help you maximise efficiency and savings. Read on to discover how to make the most of your solar energy setup.

Location has an enormous impact on how well your solar panels, also called photovoltaics, will perform. This is because location significantly impacts how much sunlight the panels will receive, directly affecting their energy production efficiency. The more direct sunlight, also called peak sunlight hours, when the sun is directly overhead, the more your array can perform at peak efficiency and the more power you can produce. Therefore, when installing a photovoltaic array on your property, spend some time planning the best location.

There are numerous factors you’ll need to consider when choosing where you should install your photovoltaic array. Let’s take a look.

The higher the elevation, the greater the solar irradiance. Solar irradiance is the light energy received from the sun measured as the power per unit area, typically expressed in watts per square meter (W/m²). Elevation also often influences shade on your property, with those higher up typically having fewer obstructions blocking the sunlight.

Latitude also affects solar irradiance since the further you are from the equator, the lower your solar irradiance. This is because the sun's rays hit the Earth's surface at a more direct angle near the equator. Locations further away mean that the sunlight has to pass through more of the Earth’s atmosphere before it reaches the surface, reducing the incoming sunlight. This doesn’t mean those in northern areas can’t use photovoltaic panels; it simply means you may need more panels to produce the same amount of power as someone closer to the equator.

The orientation of the photovoltaics is one of the most important factors since this will also determine how much direct sun they will receive. Anywhere in the Northern Hemisphere, panels should optimally face south to maximise the amount of direct sunlight hours. If southern exposure is unavailable, east or west are next best, with north being the least efficient. In the Southern Hemisphere, the orientation is opposite, with the north being the most optimal.

Local climate and weather patterns also significantly affect photovoltaic efficiency. Anything that obstructs incoming sunlight, including clouds, fog, dust, and air pollution, can reduce the light hitting the panels and impact their efficiency.

Again, it doesn’t mean someone in a particularly rainy climate cannot use solar since your panels will still produce even on a rainy day when they only receive diffused indirect sunlight. They simply wouldn’t produce as much as they would if those same panels were installed in a less rainy climate with clearer skies, like a desert.

Seasonal variation also impacts efficiency because the number of daylight hours and the intensity of sunlight will vary in locations with seasonal variation. They’ll produce more in the summer when there is more available light and the sun is higher in the sky and less in the winter months when there are fewer daylight hours.

Anything that casts shade on your photovoltaic panels will reduce your efficiency, sometimes dramatically. This is why choosing a location with little to no shade is critical, especially during those peak sunlight hours when the sun is as close to being directly overhead as possible, usually in the early afternoon.

The angle at which the panels are tilted will also dramatically influence efficiency. Generally, the panels should be tilted at an angle approximately equal to the latitude to capture the most sunlight. To have them perform even better, you can adjust them seasonally. In the UK, during the summer, when the sun is higher in the sky, placing them at a shallower angle of about 30° will maximise direct sunlight. In the winter, switching to a steeper angle of about 50° is best since the sun is lower in the sky, allowing the panels to capture more direct sunlight.

Accessibility is also a factor since panels that are difficult to access will be more challenging to maintain. To keep them performing their best, they should be cleaned and check their wiring 1-2 times yearly. Accessing them so you can adjust them seasonally will also improve their performance.

Finally, check your local zoning regulations. While photovoltaics are generally allowed in most locations, permits are sometimes required. Furthermore, the regulations may restrict or limit how you install your photovoltaic array in some instances.

The amount of solar energy can vary significantly with location. For instance, areas higher in elevation will receive greater solar irradiance than those lower in elevation because they have less atmosphere to travel through. 

For the same reason, those in far northern or far southern locations will also have less direct sunlight since the sun is directly overhead at the equator. As you move away from the equator, the sunlight travels through the atmosphere at an angle, resulting in more sunlight being absorbed and scattered before it reaches the surface of your panels. 

Another factor is orientation. In the northern hemisphere, southern exposure will receive far more direct sunlight than one with north exposure. Still, this does not mean only those near the equator can produce solar energy. You can use photovoltaics anywhere the sun shines, which is virtually everywhere except for the high Arctic during their 24 hours of darkness in the winter. 

If you live in a less-than-ideal location, you may need a few more panels than someone in a more ideal location. Furthermore, you can significantly increase the efficiency of your photovoltaic array by using it with a battery backup system. 

For instance, the EcoFlow Power Ocean (Single-Phase) and the EcoFlow Power Ocean (Three-Phase) start at 5kWh of capacity, perfect for use with an on-grid system. This allows you to still use solar at night or during peak electricity hours when your tariff rates are the highest. It also works as a battery backup system to keep your lights on when the grid goes down. 

Those with larger homes, more essential appliances, or who want to go off-grid can add additional batteries to increase their capacity to 45kWh. That’s enough power to last for days during a power cut or indefinitely off-grid. 

If you already have a photovoltaic array, you can use the EcoFlow PowerOcean DC Fit to retrofit your existing solar array easily. Simply install it between your array and your existing inverter; no need to change anything in your current setup. Then, you can maximise your solar power efficiency.

The angle at which the panels are tilted will also dramatically influence efficiency. To capture the most sunlight, panels should be tilted at an angle approximately equal to the location's latitude. It's also recommended that they be adjusted seasonally to perform even better. For instance, in the summer, when the sun is more directly overhead, placing them at a lower angle of about 30° will maximise direct sunlight in the UK. In the winter, a steeper angle is used, about 50°, since the sun is lower in the sky, and a steeper angle will capture more direct sunlight.

In the Northern Hemisphere, the best location for solar energy is on a south-facing roof with high amounts of sunlight and no buildings or trees causing shade. In the UK, panels should be placed at an angle of between 30° and 50° to maximise the amount of direct sunlight they receive.

How much direct sunlight your solar panels can receive depends entirely on location. Areas higher in elevation and lower in latitude receive the most direct sunlight. Orientation toward the equator, local climate, and shade from buildings or trees also play a significant role.

Your location is crucial in determining how much solar energy you can generate. While factors like elevation, latitude, and shading affect efficiency, strategic placement, proper angling, and battery storage solutions can significantly improve the performance of your system. Even in less-than-ideal locations, a photovoltaic system remains a wise investment with the right setup. If you’re ready to maximise your solar energy production, consider incorporating a high-efficiency battery backup like the EcoFlow Power Ocean (Three-Phase) to store excess energy and ensure round-the-clock availability of clean power.