The Bifacial or Double Sided Solar Panel is becoming popular as an efficient and economical alternative to generate renewable energy. In this article, I’ll explore what a bifacial solar panel is, how it works, and its advantages and disadvantages.
What is a bifacial solar panel?
A bifacial solar panel can produce solar energy from both the top and bottom. This is possible because the photovoltaic cell is installed on a transparent substrate and can capture sunlight that reflects on the bottom surface of the panel.
How does a bifacial solar panel work?
Bifacial panels work similarly to traditional photovoltaic panels. They absorb solar radiation and transform it into electrical energy through photovoltaic cells. The main difference is that the bifacial solar panel can capture sunlight that reflects on the lower surface of the panel, thus increasing its efficiency.
Bifacial photovoltaic panels have two glass faces, one upper and one lower. The upper face is exposed directly to sunlight, while the lower face receives solar radiation reflected from the surface below it, such as soil, water, tiles, or snow. The light reflected from the lower face can generate electrical energy, as is the light captured by the upper face.
Benefits and Advantages of the Bifacial Solar Panel
1. Higher efficiency: As this solar module model can generate energy from reflected light, bifacial solar panels can produce more energy than conventional solar panels.
2. Flexibility: Bifacial solar panels can be installed in various configurations, such as different inclinations, which increases installation flexibility.
3. Durability: The bifacial solar panel is designed to be more durable than conventional solar panels due to its robust construction and choice of rigid materials. The bottom surface of the solar panel is made of a highly resistant material, such as tempered glass or polycarbonate, which can withstand adverse weather conditions such as high winds, rain, and hail.
This material is chosen to resist impacts and prevent breakages or cracks in the panel’s surface, which could affect the efficiency of solar energy generation. They typically have a sturdy aluminum frame that protects the panels from bending and twisting and are designed to withstand wind and snow loads.
Some models also have an additional layer of weather protection, such as special polymer coatings or anti-corrosion treatments to prevent long-term degradation.
4. Takes up less space: As bifacial solar panels generate electrical energy from both sides, they can be installed in smaller spaces than conventional solar panels to generate the same amount of energy, making them ideal for residential rooftops.
Disadvantages of Bifacial Solar Panels
Cost: This is one of the main challenges for using bifacial solar panels on a large scale. Due to its more complex construction, bifacial technology is more expensive than conventional solar panel technology.
Furthermore, the production of bifacial panels involves more advanced processes, such as manufacturing solar cells on both sides of the panel, which further increases the production cost.
Another factor that can increase the cost of bifacial solar panels is the need for additional components for their installation. For example, to ensure the capture of light reflected from the ground, bifacial panels need to be installed on elevated support using brackets, such as a solar tracking structure, which can increase the system’s total cost.
1. Increased vulnerability to damage: Bifacial solar panels have solar cells on both sides, making them more vulnerable to damage from hail, high winds, and other external impacts.
2. Require specific support: Bifacial photovoltaic panels need specific support to ensure that they are positioned to capture light from both sides, which can increase the installation cost.
3. More difficult cleaning: Cleaning bifacial solar panels can take a little more work than cleaning conventional solar panels, as bifacial panels have solar cells on both sides and, therefore, require cleaning on both sides to clean them. Ensure maximum energy production.
What are the characteristics of bifacial solar panels?
The bifacial solar panel is a relatively new technology with some distinct characteristics compared to traditional solar panels. Here are some of the most essential features of the bifacial solar panel:
1. Double-sided: The most striking feature of the bifacial solar panel is that it has two faces (or sides) capable of absorbing sunlight, one at the top and the other at the bottom of the panel. This increases the panel’s efficiency, as it can capture sunlight reflected off the ground, water, or other surfaces.
2. Material: Bifacial solar panels are made from materials similar to traditional solar panels, usually with polycrystalline or monocrystalline silicon layers. However, the bottom surface of the panel is generally more reflective than the top to maximize absorption of reflected sunlight.
3. Structure: Bifacial solar panels usually have a tempered glass structure, which protects the internal solar cells and helps reflect sunlight to the bottom of the panel. The structure can be transparent or translucent, depending on the panel design.
4. Guidance: Bifacial solar panel installation is essential to maximize efficiency. Depending on the location and power generation needs, they can be installed in different orientations, inclinations, and heights.
5. Efficiency: Generally, bifacial solar panels are more efficient than traditional solar panels, as they can absorb more sunlight from two sides instead of just one. According to studies, the efficiency of bifacial solar panels can be 10% to 27% higher than that of conventional solar panels.
Construction of Bifacial Modules
Bifacial modules are constructed similarly to traditional solar panels, with some differences in the top and bottom layers. Here is an overview of the construction process of the bifacial modules:
1. Solar cells: The process begins with the manufacture of solar cells, usually made of crystalline silicon. Bifacial solar cells have an additional layer of silicon on the back to allow reflected sunlight to be absorbed.
2. Lamination: Solar cells are placed between layers of EVA (ethylene-vinyl-acetate) and tempered glass and then subjected to high temperatures and pressure in a process called lamination. This creates a solid and durable solar module.
3. Textured Glass: The module’s top layer of glass is textured to maximize sunlight absorption. This can be done in various ways, like acid or sandblasting.
4. Reflective Films: The bottom layer of the module is coated with a reflective film to reflect sunlight reaching the back of the module to the solar cells. This increases the amount of sunlight available to generate electricity and improves the module’s efficiency.
5. Electrical Connection: Solar cells are connected in series or parallel to produce the voltage and current required to generate electricity. Then, the electrical connectors are soldered to the solar cells,, and the connections are covered with an insulating material.
6. Quality testing: Before being sent to installation, bifacial modules undergo a series of tests to ensure they function correctly and produce the specified amount of energy.
The surface that reflects light also plays an important role
The surface on which bifacial modules are installed significantly impacts their performance. Substrate reflectivity, also known as albedo, plays a decisive role.
Flat, glossy surfaces reflect more sunlight and thus increase the output of the back of the module. Different materials have different albedo values, with white surfaces and snow reflecting light better.
Choosing the suitable surface beneath the bifacial panels, for example, painted concrete instead of grass can significantly impact the efficiency of the bifacial modules.
Bifacial solar panel: What features and when does it pay off?
The bifacial solar panel has several functionalities and is an attractive option in many situations. Below, we will explore some of the features of the bifacial solar panel and when it can be advantageous to opt for this technology.
1. Power generation in low light conditions: Bifacial solar panels can collect reflected sunlight, increasing their efficiency and allowing them to generate power even in low light conditions, such as cloudy, snowy, or shaded days. This makes the bifacial solar panel attractive in locations with these climate conditions.
2. Usage in different orientations and inclinations: Bifacial solar panels can be installed in different orientations and inclinations, which means they can be installed on flat roofs or at lower angles than traditional solar panels. This makes them ideal for space-constrained locations or installation on building facades.
3. Usage in urban and industrial areas: Bifacial solar panels are ideal for urban and industrial areas where nearby buildings, walls, and other reflective surfaces can reflect sunlight. These panels can capture reflected sunlight and generate more energy than traditional solar panels in these conditions.
When it comes to the tradeoffs for bifacial solar PV, it depends on several factors, such as the price of the panels, the availability of technology in your region, climate and sunlight conditions, and your energy consumption profile.
Generally, the bifacial solar panel is an attractive option in urban, industrial, or areas with reflective surfaces and places with low light conditions. It is essential to consider all these factors when deciding whether the bifacial solar PV array is the best choice for your solar PV power generation needs.
Conclusion
Bifacial solar panels are a promising option for renewable energy generation. They have a higher efficiency and more excellent durability than conventional solar panels.
However, the higher cost can hinder wide-scale adoption, and slightly lower efficiency in low-light conditions can be challenging in some regions. Still, with the continued increase in demand for renewable energy, bifacial solar panels will likely become more common.
For anyone considering installing bifacial solar panels, it is essential to evaluate the costs and benefits carefully. The added efficiency and durability can be a significant long-term benefit, but the upfront cost can be a hurdle for some consumers.
Additionally, it is essential to remember that installing bifacial solar panels requires a surface that can reflect sunlight to the underside of the panel, which may not be possible in all situations. Working with a qualified professional to evaluate the feasibility of a bifacial solar panel installation on your property is essential.