As solar technology develops, bi facial solar panels are becoming an increasingly popular option for certain solar installations. Unlike conventional panels that primarily generate electricity from their front surface, bifacial panels are designed to capture sunlight from both the front and rear.
This additional generation potential can make bifacial technology particularly useful where the panels are installed above reflective surfaces or in environments where plenty of light can reach the rear.
Understanding the technology, efficiency and factors affecting energy generation can help you decide whether bifacial solar panels are suitable for your project.
What Are Bi Facial Solar Panels?
Bi facial solar panels, also known as bifacial solar panels, are photovoltaic panels capable of generating electricity from sunlight reaching both sides.
The front surface captures direct sunlight, while the rear surface can capture reflected and diffuse light.
The amount of electricity generated from the rear depends on the installation conditions, including:
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Surface reflectivity.
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Panel height.
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Panel spacing.
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Orientation.
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Panel angle.
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Shading.
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Surrounding environment.
How Does Bifacial Solar Technology Work?
Solar cells generate electricity when light reaches them. In a bifacial panel, the cells are designed so that light can reach them from both sides.
The front side receives direct sunlight, while the rear side can make use of light reflected from surfaces underneath the panel.
For example, light-coloured surfaces can reflect additional sunlight towards the rear of the panels.
This means the design of the entire installation can have a major impact on bifacial performance.
Understanding Solar Panel Efficiency
Solar panel efficiency refers to how effectively a panel converts available sunlight into electricity.
When comparing bi facial solar panels, it is important to consider both the front-side efficiency and the potential contribution from the rear.
A high-efficiency panel can generate more electricity from a given amount of roof or ground space, which can be especially useful where installation space is limited.
What Is Bifaciality?
Bifaciality is an important specification when comparing bifacial solar panels.
It indicates the rear-side electrical performance of a panel relative to its front-side performance under specified testing conditions.
A higher bifaciality rating can provide greater potential for additional rear-side generation when the installation allows sufficient light to reach the back.
However, the rating alone does not determine how much extra electricity the system will generate.
What Affects Bifacial Energy Generation?
The actual performance of bi facial solar panels depends heavily on the installation environment.
Surface Reflectivity
The surface underneath the panels can influence how much light reaches the rear.
Light-coloured and reflective surfaces can provide greater opportunities for rear-side generation.
Panel Height
The distance between the panels and the surface underneath can affect the amount of reflected light reaching the rear.
Panel Spacing
Adequate spacing can help prevent panels from blocking useful light from reaching the rear of neighbouring panels.
Shading
Trees, buildings and other structures can reduce available sunlight and therefore affect generation.
Orientation and Angle
The position of the panels affects how much sunlight reaches the front and rear surfaces throughout the day.
Are Bi Facial Solar Panels More Efficient?
Bifacial panels can produce more total electricity than comparable single-sided panels when the installation conditions are favourable.
However, they do not automatically produce significantly more electricity in every situation.
For example, if the rear of the panels is installed close to a dark surface with very little reflected light, the additional benefit may be limited.
This is why professional system design is particularly important when considering bifacial technology.
Bi Facial Solar Panels in the UK
Bifacial solar panels can be used in the UK and can generate renewable electricity throughout the year.
As with all solar PV technology, electricity production varies depending on available sunlight.
Summer generally provides longer daylight hours and stronger solar generation opportunities, while winter typically produces less electricity.
Bifacial panels can still use available diffuse and reflected light, but the additional benefit will depend on the individual installation.
Where Are Bifacial Panels Most Suitable?
Bi facial solar panels can be particularly suitable for installations where light can reach the rear surface.
Potential applications include:
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Ground-mounted solar systems.
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Solar farms.
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Commercial rooftops.
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Solar carports.
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Raised solar installations.
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Certain flat-roof systems.
The suitability of bifacial technology depends on the specific design and surrounding environment.
Bifacial Panels on Flat Roofs
Flat roofs can sometimes provide suitable conditions for bifacial solar panels.
Panels can be mounted at an angle and raised above the roof surface, allowing some light to reach the rear.
The potential benefit depends on:
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Roof surface colour.
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Panel height.
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Panel spacing.
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Panel orientation.
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Shading.
A professional assessment can determine whether a flat roof is suitable for bifacial technology.
Ground-Mounted Bifacial Systems
Ground-mounted systems can provide excellent opportunities for bifacial panels because there can be more space beneath and around the panels.
The surface beneath the system can also be selected or designed to improve light reflection.
This can potentially increase the amount of light reaching the rear and improve total electricity generation.
Combining Bifacial Panels With Battery Storage
Battery storage can complement bi facial solar panels by allowing excess electricity to be stored for later use.
During periods of strong solar generation, your panels may produce more electricity than your property immediately requires.
A compatible battery can store some of this excess energy for use when solar generation is lower.
This can help:
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Increase self-consumption.
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Reduce reliance on grid electricity.
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Improve energy management.
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Make better use of renewable generation.
Comparing Bifacial Solar Panels
When comparing bi facial solar panels, look at the complete set of specifications rather than focusing on one number.
Important factors include:
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Front-side efficiency.
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Bifaciality rating.
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Power output.
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Panel dimensions.
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Product warranty.
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Performance warranty.
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Durability.
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Manufacturer reputation.
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Temperature characteristics.
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Installation requirements.
It is also important to consider whether your site can provide enough rear-side light to justify choosing bifacial technology.
Choosing the Right Inverter
The inverter converts the DC electricity produced by your solar panels into AC electricity that can be used by your property.
When installing bi facial solar panels, the inverter should be appropriately sized and compatible with the panels and wider system.
A professional installer can help select the appropriate inverter and ensure the complete system is correctly configured.
Choosing a Solar Supplier
An experienced solar supplier can help assess whether bifacial technology is appropriate for your project.
They can evaluate:
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Roof or ground conditions.
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Surface reflectivity.
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Panel spacing.
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Panel height.
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Shading.
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Orientation.
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Inverter compatibility.
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Battery storage requirements.
Good system design can help maximise the potential benefits of bifacial technology.
Final Thoughts
Bi facial solar panels provide an innovative approach to renewable electricity generation by capturing sunlight from both the front and rear surfaces.
Their potential for additional energy generation makes them particularly interesting for ground-mounted systems, commercial installations, solar carports and suitable flat-roof projects.
However, the performance of bifacial technology depends heavily on installation conditions. Surface reflectivity, panel height, spacing, shading and orientation can all influence the amount of additional electricity generated.
By understanding these factors and choosing the right equipment and installation design, property owners can determine whether bifacial solar technology is the right solution for maximising renewable energy generation.
