What are bifacial solar panels?

• Bifacial solar panels generate power from the front and rear surfaces
• They produce between 10-30% more electricity than ‘monofacial’ panels
• They are more expensive than conventional panels

You probably know that solar panels can cut your energy bills and your carbon footprint already, but you might not be aware that you can double your gains by using bifacial solar panels.

The technology is similar to regular (or ‘monofacial’) solar panels, but they generate power from both front and rear surfaces, helping you claw more back from your energy bill.

We’ve put together this guide to walk you through what bifacial solar panels are and how they could help you save money and carbon.

What is a bifacial solar panel?

A bifacial solar panel is similar to a regular, or ‘monofacial’, solar panel, except that it generates electricity on both its front and rear surfaces.

While ‘monofacial’ is not a common name, we’ve used it throughout this guide to easily distinguish them from bifacial solar panels.

How do bifacial solar panels work?

Bifacial panels have a layer of protective glass on the front and a transparent polymer sheet on the back through which sunlight can pass through. They have PV cells on the front and the rear, allowing them to generate more energy than monofacial panels.

The PV cells on the front absorb light and generate power in the same way a monofacial panel does, but the difference with bifacial solar panels is that the cells on the back absorb light that is reflected off the ground, allowing you to generate more electricity.

Most bifacial solar panel designs also have dual glass at the rear, which means they can transmit light more efficiently and are also more resilient to the weather and moisture.

How are bifacial solar panels installed?

To take advantage of the fact they can generate energy on both sides, it’s best to install bifacial solar panels on a ground-mounted or elevated racking system so that the backsheet can absorb light.

Ground-mounted systems tend to fall into one of two main types: vertical and horizontal.

Vertical involves installing panels at angles, enabling them to receive the maximum sunlight during the day.

This method is typically reserved for ground-mounted PV farms or installations in open areas like fields. It can also consist of installed panels in more novel locations, such as bodies of water (for a floating array).

Horizontal installations generally consist of installing the panels at flatter angles, with light reflected onto them by surfaces from like gravel, sand, light stone, or highly-reflective materials.

A typical use case for a horizontal installation would be on the pitched roof of a home.

Sun tracking options can also be installed to boost the efficiency of PV installation as they can track (and change tilt angle) in response to the motion of the Sun throughout the day.

Speaking to The Eco Experts, Jon Camp, managing director at solar panel manufacturer RECOM Technologies said bifacial solar panels offer several advantages.

“Firstly, they can generate electricity from both sides, capturing sunlight reflected from the ground or surrounding surfaces,” Camp explained.

“This increased energy yield can result in higher overall power output compared to monofacial panels.

“Their versatility allows for installation in various orientations, maximising energy production in different environments.”

Where should I install a bifacial solar panel?

Like regular solar PV panels, bifacial panels can be installed in multiple places, but there are few things to think about before you get do so.

These include height, reflectivity, and anything around that might get in the way, or cause shading.

Because they can generate electricity from both sides, bifacial solar panels are ideal for flat roofs and large utility space, such as industrial parks and farms.

Can I save money with bifacial solar panels?

To answer this question in short, yes, you can, but not immediately.

Solar panels cost a fair bit upfront, but they will reduce your electricity bill by up to 70% from the moment they are installed. With an average lifespan of around 25 years, your solar panels will have paid for themselves within about 14 years, and they will make you money in the long run.

How much money you’ll save depends on the size of the system, where and how it is installed, and the fluctuating cost of grid-supplied electricity over time.

The same is true for bifacial solar panels, perhaps more so as these units generate, relatively speaking, more electricity per panel (estimates are between 10-20% more) than conventional solar PV panels.

However, they are generally more expensive than monofacial solar panels, with upfront costs roughly between £2,000 and £13,000 for a typical domestic setup.

Like their monofacial counterparts, bifacial solar panels typically have a lifespan of at least 25 years. However, like any technology, this relies on proper maintenance and care over time, attracting ongoing costs throughout the system’s lifetime.

How much energy can bifacial solar panels generate?

Similar to cost savings, the energy bifacial panels can produce depends on a number of factors. These include, the size of the system installed, where and how it is installed, and the typical weather conditions.

Like monofacial panels, the geographic location, the angle of the panels, intensity and direction of sunlight, time of year, efficiency and quality all play their part in determining the electrical generation capacity of a PV system.

Recent studies of bifacial panels in China found that ‘standard’ bifacial panels can produce at least 11% more electricity than conventional panels.

When augmented with solar tracking technologies (a system that moves the panels to track the Sun’s motion through the sky throughout the day), bifacial panels can see an astonishing 27% increase over conventional panels.

That is not to be sniffed at.

Are bifacial solar panels better than monofacial panels?

Reducing your reliance on grid-supplied electricity can be really beneficial, regardless of which system you choose, but there are some key differences between bifacial and monofacial solar panels.

Cost

Bifacial solar panels are more expensive upfront than monofacial ones, but as they generate more electricity, they will pay you back quicker (as a return on investment) in the long run.

As a very rough rule of thumb, bifacial solar panels typically cost about 10% more than conventional solar panels. As the average domestic solar PV installation in the UK is around £9,180, a typical bifacial installation should set you back closer to the £10,000 mark.

Power

Bifacial solar panels typically produce between 10-30% more electricity than conventional solar panels. This means you get more electrical generation due to the amount of space the panels occupy.

This means, in theory, you could install 25% fewer panels to get the same amount of solar energy as a monofacial solar PV system.

Maintenance

Bifacial solar panels are typically more robust and durable than monofacial solar panels. This is because both sides of the panels are covered with tempered glass.

Tempered glass is weather-resistant, UV-resistant, and better at holding up against wind and temperature fluctuations over the years.

For this reason, bifacial solar panels require relatively less maintenance than conventional solar panels. Manufacturers typically give them a 25-year lifetime warranty, but some also offer 30-years.

Like monofacial solar panels, some parts of a bifacial solar PV installation, such as the inverter, may require regular replacements or servicing. These typically last between a decade and 12 years.

How do I look after a bifacial solar panel?

On the subject of maintenance, it’s important to take care of your bifacial solar panel if you want to enjoy its benefits.

To that end, you’ll want to make sure you do the following things to keep them in top-notch working condition:

• Like monofacial solar panels, bifacial ones require regular cleaning. This keeps their surfaces free of dirt and grime, enabling as much sunlight as possible to reach the solar cells. Also, when cleaning them, make sure this is when they are cold to reduce the risk of damaging them from things like thermal stress.
• You should also regularly inspect the panels for damage. If any is found, get a professional to make the necessary repairs.
• Another often overlooked consideration with solar panels is shading. This is when something casts a shadow or otherwise impedes sunlight hitting a solar panel’s surface. Tree branches and surrounding buildings can reduce the power output of solar panels, so think carefully about where you choose to install them.
• Make sure you constantly hire the services of a trained professional to inspect and service your solar panels and ancillary equipment regularly. Just like other things in your home, like your boiler, this will significantly extend the life of the panels and may be a condition of the warranty, too.

Can bifacial solar panels be installed on residential buildings?

Absolutely, they can but they are better suited for larger installations like those used for industrial projects or solar farms. Under these kinds of installations, more light can be reflected onto the rear surfaces, maximizing their potential.

While possible, it is hard to make the most of bifacial solar panels if installed on roofs, so they aren’t strictly designed for residential buildings like monofacial panels.

According to Jon Camp, installing bifacial solar panels on residential buildings can pose challenges due to the limited space and shading issues in urban environments.

“While it is possible to benefit from the extra power generation of bifacial panels on rooftops, proper planning and consideration are essential,” the company explained.

“With strategic placement and appropriate tilt angles, homeowners can still harness the advantages of bifacial panels on their rooftops.”

The company explained that bifacial solar panels are well-suited to environments with “ample space and reflective surfaces, such as industrial areas, open fields, or agricultural lands”.

“In these settings, the panels can benefit from increased sunlight exposure and light reflection, enhancing their energy generation capabilities.

“Additionally, their adaptability to different mounting configurations makes them suitable for ground-mounted installations, optimising space utilisation in large-scale projects like solar farms.”

The pros and cons of bifacial solar panels

How do I choose the best bifacial solar panel?

We’ve covered some of the main things you need to know about bifacial panels above, but you should try to find models that offer the best of the following attributes:

• Efficiency
• Durability
• Cost
• Manufacturer (currently limited choice in the UK)
• Warranty (longer the better)
• Monocrystalline or polycrystalline (the former is more expensive but more efficient)

Things to consider before buying bifacial solar panels

Like any big-ticket item you buy, you should shop around for the best deal. This will be a combination of the price, the building you wish to install them on, and how much sunlight the panels will realistically receive.

Reputable installers should be very well placed to provide you with this advice, which will typically be a significant part of the quotation process.

Getting a few quotes is often the best thing to do, and don’t be afraid to ask for referrals from happy customers.

The advice from RECOM Technologies is to first assess space and surroundings to make sure the bifacial solar panels will get enough sunlight. This includes potential shading issues and how to maximise energy production.

“It’s crucial to consider the cost-effectiveness of bifacial panels compared to monofacial options and inquire about warranties and product reliability,” the company said.

Is the UK bifacial solar panel market growing?

Yes, according to RECOM Technologies. The company said that the UK market is “poised for significant growth in the coming years” due to the potential benefits of solar power.

“With increasing emphasis on renewable energy adoption and sustainability initiatives, bifacial panels offer an attractive solution for maximising energy production in various applications.

“As technology advancements continue to drive down costs and improve efficiency, we anticipate a surge in demand for bifacial panels across commercial, industrial, and residential sectors.

“Factors such as favourable government policies, rising energy prices, and growing environmental awareness will further contribute to the expansion of the bifacial solar panel market in the UK.”

Summary: Are bifacial solar panels worth the money?

In short, yes. Solar panels (monofacial or bifacial) offer interesting options to help you reduce energy costs and do your little bit for the planet.

However, they are relatively uncommon in the UK, so you’ll want to do more research to find the best fit for you.

• Bifacial panels are dual-faced, meaning you get more bang for your buck when installed.
• They are typically between 10 and 30% more efficient than conventional solar panels.
• These panels also tend to last longer, with expected lifespans of 30 or more years.
• They are more expensive, but the higher efficiencies offset the additional cost handsomely.