Bifacial vs Monofacial Solar Panels: Benefits & Costs 2025

As the UK continues its transition to renewable energy, homeowners, landlords, and commercial property owners are increasingly investing in solar energy. When choosing solar panels, two main types dominate the market: bifacial and monofacial solar panels. 

Understanding their differences is crucial for making a smart investment. In this guide, we'll break down the key distinctions, helping you choose the right panel type for your property.

Bifacial vs Monofacial Solar Panels - A Quick Overview

Before diving deeper, here’s a quick side-by-side comparison to help you understand the main differences between bifacial and monofacial solar panels.

If you're considering solar panels, Eco Answers offers a free quote-comparison tool. Our easy-to-use platform matches you with trusted UK suppliers offering tailored solar quotes. Compare solar panel quotes with Eco Answers.

Bifacial Solar Panels

Bifacial solar panels are an advanced type of photovoltaic (PV) panel that can absorb sunlight from both the front and rear sides, unlike traditional panels, which only capture light from one side. 

The front side faces the sun directly, while the rear side collects reflected sunlight (also called albedo light) from surfaces like light-coloured gravel, concrete, white roofing, grass, or snow.

This dual-sided design makes bifacial panels particularly efficient in environments with high surface reflectivity or open spaces where light can bounce back onto the rear side.

They are most commonly constructed with glass on both sides (known as dual-glass or glass-glass panels), or with a transparent backsheet, allowing the sunlight that passes through or reflects underneath to still be absorbed and converted into usable electricity.

How do they work?

The working principle of bifacial solar panels is similar to monofacial panels. They use silicon solar cells to convert solar energy into electricity through the photovoltaic effect. 

However, bifacial panels are engineered to maximise light exposure on both surfaces, increasing overall yield.

Here’s a simplified breakdown of the process:

1. Direct sunlight strikes the front of the panel and generates electricity, just like any solar panel.
   
2. Reflected sunlight from surrounding surfaces bounces onto the rear of the panel, providing additional light exposure to the backside solar cells.
   
3. Combined output from both sides increases total generation, especially in optimal installations (e.g. tilted, raised, or ground-mounted on reflective surfaces).

According to the Energy Saving Trust, standard solar panel systems in the UK typically operate at 15–20% efficiency, while bifacial panels can exceed that by an additional 10–30% depending on placement, surface reflection, tilt angle, and location.

Monofacial Solar Panels

Monofacial solar panels are the most widely used and recognised type of solar panel in the UK and globally. 

As the industry standard for decades, these panels are designed to absorb sunlight solely from the front-facing side, the side directed toward the sun. They are typically seen on residential rooftops, commercial properties, and solar farms.

Monofacial panels come in two common varieties:

• Polycrystalline (blue) panels, which are less expensive but slightly less efficient
• Monocrystalline (black), which offer higher efficiency and a more uniform appearance, making them popular among UK homeowners

Their simple, durable construction makes them suitable for a wide range of roof types and climate conditions found throughout the UK.

Insights: If you would like to learn about the differences between these types of panels, our guide comparing monocrystalline and polycrystalline solar panels breaks down the pros and cons of each to help you get a better understanding. 

How do they work?

Monofacial panels work by harnessing the photovoltaic effect. Each panel consists of multiple solar cells made from silicon, a semiconductor material that generates electricity when exposed to sunlight. Here's how they function in simple terms:

1. Sunlight hits the front of the panel, exciting the electrons in the silicon cells.
2. This movement of electrons creates a direct current (DC) of electricity.
3. An inverter converts the DC electricity into alternating current (AC), which can be used in your home or exported to the National Grid.

The back of a monofacial panel is typically covered with an opaque backing material, often white or black, which protects the internal components and helps prevent light leakage. 

Unlike bifacial panels, the rear side is not designed to absorb or utilise any reflected sunlight..

Because of their proven reliability, cost-effectiveness, and ease of installation, monofacial solar panels remain the go-to choice for most UK homes, especially in urban and suburban settings where roof space is limited and consistent performance is needed.

Bifacial vs Monofacial Solar Panels: Key Differences

Let’s explore the detailed differences across the most important criteria.

Efficiency

When comparing bifacial and monofacial solar panels, the efficiency difference goes beyond surface-level performance. 

While monofacial panels typically offer conversion efficiencies between 18–22%, they can only generate electricity from the front-facing side, meaning any light that doesn't strike this surface directly is essentially lost.

Bifacial panels, by contrast, not only convert direct sunlight but also leverage reflected and diffused light from their surroundings. 

This allows them to achieve effective gains of 10–30% over monofacial panels in real-world installations, especially where high albedo surfaces or elevated mounting structures are present.

For example, a 400W bifacial panel might yield the equivalent energy output of a 460–520W monofacial panel under optimal conditions.

Another key distinction is performance consistency. Monofacial panels are more affected by suboptimal conditions like overcast skies or partial shading, whereas bifacial panels can maintain a more stable output by capturing ambient light from multiple angles.

Bifacial panels also tend to benefit from lower temperature coefficients and more advanced cell technologies (like half-cut or PERC cells), making them less prone to efficiency drops on hot days, another subtle but important difference that can lead to greater long-term yield compared to monofacial systems.

Insights: For a deeper look into how hot weather impacts solar performance, read our article on how extreme heat affects solar panels.

Ultimately, the efficiency advantage of bifacial panels translates to greater energy density per installation, particularly useful for commercial projects, solar farms, or any application where squeezing the most energy out of available space is critical.

Winner: Bifacial Panels

Costs

The initial investment for bifacial solar panels is generally higher than for monofacial panels. This cost difference arises from several factors, including the use of double-glass construction, more robust mounting systems, and often premium cell technology. 

Additionally, installation can be more complex, especially when optimising for ground reflectivity or tilt angles, which may increase labour or racking costs.

However, this upfront premium can be offset by long-term performance gains. 

Bifacial panels’ ability to generate more energy per panel reduces the number of panels needed for a given output, potentially lowering costs for ancillary components like inverters, wiring, and support structures in larger systems.

From a Levelized Cost of Energy (LCOE) perspective, a metric that calculates the cost per kilowatt-hour of electricity generated over a system's lifetime, bifacial panels often outperform monofacial systems in the long run. 

Their higher energy yield means faster payback periods, particularly in setups that maximise rear-side irradiance (e.g. reflective ground surfaces or elevated installations).

In contrast, monofacial panels are less expensive upfront and have simpler installation requirements, making them a more attractive option for homeowners or small-scale installations with limited budgets. 

However, they may require more panels and more roof space to achieve the same output as a well-optimised bifacial system, which could limit their scalability or long-term ROI.

For UK consumers, financial incentives such as the Smart Export Guarantee (SEG) and various local green energy grants can help offset installation costs for both types, but the higher yield potential of bifacial systems can lead to greater cumulative savings over a 25–30 year lifespan.

According to the Energy Saving Trust, the average UK household saves around £450 a year on electricity bills with solar panels.

Winner: Bifacial Panels

While monofacial panels remain the more affordable choice upfront, particularly appealing for smaller budgets or simpler residential installs, bifacial panels are the clear winner when considering long-term value. 

Their higher energy output, better efficiency in well-optimised setups, and stronger lifetime return on investment make them the superior option for those with the space, budget, and conditions to support them.

For homeowners or businesses planning a long-term solar strategy, especially in installations where rear-side irradiance can be maximised, the slightly higher initial cost of bifacial panels is often justified by the significant cumulative savings over their lifespan.

Insights: Read our guide on the cost of solar panels to gain clearer insights and make a more informed decision.

Maintenance & Servicing

Bifacial solar systems may require more frequent inspection than monofacial systems, not because they are inherently more fragile, but because their performance relies on both the front and rear sides being exposed to light. 

For instance, rear-side shading from weeds, dirt build-up, nearby clutter, or even snow accumulation (depending on location) can significantly reduce energy gains. 

This is especially relevant for ground-mounted or elevated systems where rear access and ground reflectivity are critical to performance.

In contrast, monofacial panels typically only need their front surface kept clean and free from debris. Since they’re usually roof-mounted and only absorb direct sunlight, maintenance is a bit more straightforward, mostly involving occasional cleaning of the front glass to maintain efficiency.

For both systems, periodic checks on wiring, inverters, and mounting hardware are recommended. 

However, bifacial systems might also require the occasional reassessment of their tilt angles, mounting height, or surrounding environment to maintain optimal reflectivity and light capture on the rear side. 

This means maintenance is not necessarily more difficult, but it is often more nuanced and site-specific.

Over the long term, both systems benefit from professional servicing at least every few years to maximise output and ensure longevity, especially given that performance degradation can impact long-term returns if not addressed.

Winner: Monofacial Panels

Insights: You can learn more about routine care and long-term upkeep in our solar panel maintenance guide.

Aesthetics

Bifacial panels typically feature a sleek, frameless design with a glass-on-glass finish, offering a more modern and minimalist appearance. This can be especially appealing for contemporary commercial buildings and architecturally designed homes.

Monofacial panels are more traditional in appearance, with a black or blue surface and opaque backing. While newer black monofacial models have improved visually, they remain more utilitarian.

Winner: Bifacial Panels (for modern aesthetics)

Best Suited For

Bifacial solar panels are best suited for environments where rear-side irradiance can be effectively utilised to boost energy output. These include:

• Commercial Rooftops: Large, open rooftops on warehouses or industrial buildings often allow for optimised panel orientation and spacing.
  
  With minimal obstructions and potential for reflective surfaces (like white roofing membranes), bifacial panels can significantly outperform monofacial alternatives.
  
• Flat Roofs with Reflective Membranes: When installed at an angle on flat roofs coated with high-albedo (reflective) materials, bifacial panels can take full advantage of sunlight bouncing back up from the surface, increasing rear-side gains.
  
• Ground-Mounted Installations: Open-field solar farms or agricultural settings offer ideal conditions for bifacial panels, especially when using elevated racking systems and reflective ground treatments like gravel, sand, or white-painted surfaces.
  
• Solar Carports and Pergolas: These elevated structures not only benefit from rear-side reflection off pavements or concrete but also provide a dual function, generating electricity while offering shelter or shading. In such setups, aesthetics and vertical space make bifacial panels more advantageous.

Monofacial panels are generally better suited for situations where space, budget, or structural design limit the practicality of bifacial systems:

• Small-Scale Residential Setups: For households with modest energy demands and limited installation area, monofacial systems offer a simpler, less expensive approach with fewer design and installation complexities.
  
• Properties with Limited Space: In urban settings or homes with shading issues, dormer windows, chimneys, or minimal roof area, monofacial panels are easier to configure without the need for elevated mounting or reflectivity considerations.

By matching panel type to the physical and operational characteristics of a property, homeowners and businesses can optimise their return on investment while ensuring system compatibility and longevity.

Winner: Depends on property type. Bifacial for commercial/open setups; Monofacial for homes.

Installation Options and Requirements

Bifacial solar panels are more sensitive to their installation environment because they rely on both direct sunlight and reflected light from the surroundings. 

As a result, careful consideration of surface reflectivity, spacing, and mounting height is crucial to unlock their full potential.

• Ground-Mounted Systems: Ideal for large-scale or rural installations where space isn’t a constraint. When paired with reflective ground coverings such as light gravel, sand, or engineered materials (e.g., white geomembranes), bifacial panels can generate up to 10–30% more energy compared to monofacial panels.
  
  Elevated racking systems further optimise rear-side exposure and airflow, which can also aid cooling and improve performance.
  
• Flat Roof Installations: Particularly effective when panels are tilt-mounted at optimal angles and spaced adequately to avoid inter-row shading. Using reflective roofing materials like white TPO membranes can enhance albedo, increasing rear-side efficiency.
  
  However, the extra height and spacing requirements may necessitate sturdier mounts and stricter wind load considerations.
  
• Carports & Walkways: These elevated, open-air structures allow bifacial panels to collect sunlight from above while capturing reflected light from below.
  
  They also serve dual purposes, providing shelter for vehicles or pathways while generating power making them popular for schools, commercial buildings, and multi-unit developments.
  
• Wall-Mounted Systems: Though less common, vertical or facade-mounted bifacial systems are emerging in architectural applications.
  
  These installations are more aesthetic and symbolic but can still contribute meaningful energy output if oriented to capture morning or afternoon sunlight and supported by reflective surrounding surfaces.

Note: Because bifacial systems often need specialised racking, precise tilt angles, and spacing to reduce shading and maximise bifacial gain, they usually require more detailed site assessments and design work than monofacial systems.

Monofacial panels are more forgiving in terms of placement and are typically easier and quicker to install. They’re also lighter and more compatible with traditional racking systems.

• Pitched Roof Installations: The most common use case in UK residential settings. Monofacial panels mount flush with the roof slope using standard rails or integrated solar mounting kits. This type of solar installation is straightforward, cost-effective, and visually discreet.
  
• Flat Roof Installations: These require tilt frames to angle the panels toward the sun. While monofacial panels won’t benefit from rear-side exposure like bifacial ones, they can still perform well if tilt angles and row spacing are optimised.
  
  They’re generally more suitable where aesthetics, weight, or wind load are concerns.
  
• Ground-Mounted Systems: Monofacial panels can be installed at ground level, though they often require more panels (and thus more space) to match the output of a bifacial setup.
  
  This option is commonly used for rural homes, smallholdings, or solar gardens where land is available and budget is tighter.

Ultimately, the right installation approach depends on the site characteristics, energy goals, and budget. Bifacial panels demand more strategic planning but offer higher potential returns, while monofacial panels are simpler and more versatile for standard installations.

Winner: Bifacial Panels (for installation versatility and output potential).

Durability

Bifacial panels are generally built with glass on both sides, commonly referred to as glass-glass construction, which makes them more robust and long-lasting than standard monofacial panels. 

This dual-glass design enhances structural integrity, reduces the risk of microcracks, and offers better protection against environmental stressors like hail, high winds, and UV degradation. 

Additionally, many bifacial models come with extended warranties of 30 years or more due to their proven long-term performance and lower degradation rates.

However, their weight can be a drawback for installations on older or structurally limited rooftops, and the glass surfaces on both sides mean extra care is needed during transport and handling.

Monofacial Solar Panels
Most monofacial panels use glass on the front and a polymer (like Tedlar) backsheet. While this makes them lighter and easier to install, it does mean they’re more susceptible to long-term wear from moisture ingress, temperature fluctuations, and physical impacts. 

That said, high-quality monofacial panels from reputable manufacturers still offer solid durability and typically come with warranties of 20–25 years.

Winner: Bifacial Panels
Thanks to their double-glass construction and superior resistance to environmental degradation, bifacial panels come out ahead in durability, especially for long-term, high-performance installations.

Bifacial vs Monofacial Solar Panels: Which One Should You Choose?

Ultimately, the right choice depends on your property's specifics and your budget. Here are some considerations:

• Roof Type: Flat roofs or open spaces? Go bifacial. Pitched roofs? Monofacial might be more practical.
  
• Budget: If upfront cost is a concern, monofacial panels are more accessible.
  
• Performance Goals: Looking for long-term ROI? Bifacial panels offer greater yield over time.
  
• Aesthetic Preferences: Modern designs favour bifacial panels, especially with glass-on-glass setups.
  
• Property Type: Commercial properties and new-build homes with open layouts are better suited for bifacial setups.

Tip: Use Eco Answers’ free quote-comparison tool to get tailored recommendations and competitive prices based on your specific property and needs.

According to UK Government, solar panels are pivotal to the UK's strategy for achieving Net Zero emissions. 

The UK Government's Solar Roadmap: United Kingdom Powered by Solar outlines ambitious planned growth of solar deployment as a cornerstone of its clean power initiative and Net Zero pathway.

FAQs

1. Do bifacial panels work well in the UK climate?

Yes. Even with frequent overcast conditions, bifacial panels still benefit from diffuse light and rear-side reflections off light surfaces like gravel or white membranes. Read our article on how solar panels perform on cloudy days to get a better understanding. 

2. Are there grants available for bifacial or monofacial panels in the UK?

Yes. The UK Government offers incentives through schemes such as the Smart Export Guarantee (SEG).

3. Do I need planning permission for solar panels?

For most residential properties, solar panels fall under "permitted development rights". Exceptions may apply for listed buildings or conservation areas.

4. Can I mix bifacial and monofacial panels?

Technically possible, but not recommended. Mixing panel types can complicate system design and reduce overall efficiency.

5. Are bifacial panels more fragile because they have glass on both sides?

No. Most bifacial panels use tempered, durable glass on both sides, making them more resistant to weather damage than some monofacial models.

Final Thoughts

Choosing between bifacial and monofacial solar panels depends on your specific goals, roof layout, and budget. While bifacial panels offer higher efficiency and long-term returns, monofacial panels remain a reliable and cost-effective choice for many UK homes.

If you’re considering solar panels, Eco Answers can help. Use their free quote-comparison tool to connect with trusted UK installers and find the best deal for your home or property. It’s quick, easy, and obligation-free.