Solar energy has garnered attention from major players in the energy sector across the globe Hence it’s getting crucial for the manufacturers to include efficiency and cost-effectiveness in a single product.
Recently, solar panel producers are making a shift from traditional panels too far advanced bifacial panels to enhance customer satisfaction and overall performance.
Bifacial solar panels are capable of capturing energy from both sides. Hence, they are able to generate more power than a traditional monofacial panel.
All panels, whether bifacial or monofacial, are collectively made up of photovoltaic cells (PV) commonly called solar cells or silicon cells.
A PV cell is an integrated electrical device that traps the light (photon particles) from the sun and transforms it into electrical energy using a chain of various chemical and physical reactions.
In this article, we will dive deep and understand how the overall functionality of these two panels differs from each other.
What is a monofacial solar panel?
Monofacial solar panels, as evident from the name, have a collection of photovoltaic cells placed only on one side. This means monofacial panels can absorb sunlight just from a single side.
The backside of the monofacial panel stays covered with an opaque or dark-coloured sheet or plastic casing which is unable to capture the sun rays.
There are a few performance limitations to the monofacial panel. The single-faced panel cannot properly function in areas where there is partial shading or if the panel location isn’t concurrent with the latitude.
But such bottlenecks are generally absent in a bifacial solar panel.
What are bifacial solar panels?
Bifacial solar panels can capture solar energy from both sides of the panel. A bifacial module is able to absorb sunlight from the front as well as the backside of a solar cell.
The bifacial panels have been around since 1966. The first bifacial solar cells were built by a Japanese researcher named Hiroshi. Back in the day, nearly all the setups used polycrystalline cells for the setup.
According to a study by ITRPV, it is evident that bifacial solar panels are going to replace 40% of monofacial panels by the year 2028.
Bifacial solar panels structure
Unlike the monofacial panels, the bifacial ones have solar cells both in the front as well as back. These solar cells are made up of two layers of semiconductor silicon (n-type & p-type) which play a key role in electricity generation.
The bifacial panels are made up of UV protection enabled tempered glass. Chemicals like Ethyl Vinyl Acetate are also used on both sides of the cells for encapsulation. This brings extra reflective properties to the rear side of the module. This subtle difference makes it possible to capture all the incident rays of the sun that fall over the solar cells present on the rear side.
The technical advancements in the usage of raw materials have successfully curtailed the previously existing problems like higher LCOE (Levelized Cost of Electricity). Today most bifacial panels use monocrystalline based PERC (Passivated Emitter and Rear Cell) which diminishes the chances of sunlight bouncing off.
The structural integrity helps in maintaining low potential-induced degradation (PID). The composite glass casing escalates energy and is aesthetically pleasing at the same time. It further provides robustness and protection against chemical abrasion.
How do bifacial solar panels work?
Bifacial panels are generally installed on a rooftop that has a shiny surface, or the ground is coloured with a reflective paint. As mentioned earlier in the article, bifacial panels can absorb sunlight from both sides. When the sunlight is incident on the surface, the photon particles are absorbed by the PV cells present in the front and rear of the panel.
During the absorption process, the silicon material present in the solar cells separates the electrons from the absorbed photon atoms.
Further, the electrons are moved through an internal electric field with a variance in charge gradient. This phenomenon produces electricity. But this electricity is in DC (Direct current) form. To make it fit for usage it needs to be converted into AC (Alternating Current) through an inverter.
For more on how solar panels generate electricity, read ‘How Do Solar Cells Work?’
Advantages of bifacial solar panels
The bifacial panels have abundant advantages over the traditional monofacial ones.
1. More energy
A bifacial solar panel can clearly generate up to 10%-20% more energy compared to a monofacial panel, given that the project size is kept constant. If external conditions like ground reflectivity, positioning can be upgraded, the surge can be even more than 20%
2. More space
A bifacial panel can be installed in a far more creative and efficient way than a monofacial mount could be.
For example, in rural areas and agricultural plots where there is an ample amount of space, the panel could be mounted and placed on a rooftop, near the ground, or literally anywhere according to the demand. As bifacial setups have dual absorption systems, you can take advantage of the reflection off the ground.
3. More durable
As the setup cost of a solar energy system is quite high, it’s essential that panels retain their performance and resilience over a longer period of time.
Because bifacial solar panels are covered with tempered glass on both sides, they tend to be sturdier than a conventional one-sided panel. The glass is guaranteed to protect the panel from strong wind and trajectories.
4. Minimization of additional accessories
Solar companies sell an additional accessory along with a traditional panel. This accessory is called a tracker. The solar trackers change the angle of the panels so that sunlight can be absorbed for an elongated period of time over the course of the day.
Trackers are very expensive, and the occurrence of any breakdown would mean additional expenditure. The properties of a bifacial panel help to produce an equivalent amount of energy without using a tracker. These panels have no mechanical parts so there is no fear of a breakdown.
Disadvantages of bifacial solar panels
With all the benefits that the bifacial solar panels provide there are a few downsides which are mentioned below.
1. Overweight
The bifacial solar panels being built with tempered glass on both sides get immensely heavy, and immobile. These heavy panels require thorough precision and experience for smoother handling. This means regular maintenance could be done only by experienced personnel. Taking its aftercare up in your own hands can be very risky.
2. Pricey
The big tag on bifacial solar panels is a significant disadvantage.
High-quality monocrystalline silicone, and UV protected glass are the main reasons for this whopping price.
As discussed earlier, due to the dual tempered glass, the panels become immobile up to an extent. Hence, the installation and servicing of bifacial solar panels can only be done by professionals. In a nutshell, the installation and maintenance cost of bifacial panels is also higher compared to single-faced traditional ones
Bifacial solar panels efficiency
You may think that a bifacial panel, will have double the efficiency on contrary to a monofacial setup but that’s not the case at all.
Obviously, the albedo of the non-luminous surface on which the panels are set up will surely have an influence on efficacy. According to a study conducted by LONGi Solar it shows a bifacial solar panel can provide up to 27% more efficiency than a single-sided one. However, this is when the set-up is done on a highly reflective surface with a proper tracking system and also monocrystalline silicon has to be used for the solar cells.
Learn how to calculate solar cell efficiency here.
Can you use bifacial solar panels for residential projects?
The current trend for all forms of renewable energy is very uphill right now.
Solar energy is no exception.
As the production costs are getting competitive, it is expected that the market for bifacial panels will grow approximately 10 times within five years.
If you’re looking to achieve energy freedom and contribute to the wellness of our environment, then you should definitely go with a bifacial panel. Not only does it take up less space, but it also produces more energy than a conventional solar panel. Further, the bifacials also add an aesthetic value to your residence.
Top global bifacial solar panel manufacturers
Every year we are witnessing something new from the manufacturers of solar panels.
Mentioned below are a few global manufacturers that have stood the test of time in performance, efficiency and in curtailing degradation. We have included innovation, and growth of the organization itself as a filtering element to build this list.
(Not in ascending or descending order)
Key takeaways
With continuous and heavy usage of fossil fuels, the degradation of our planet has been disastrous over a period of time. Solar energy could be one of the prime pillars of decarbonisation all over the world. It can be used to produce electricity for our homes, and various industries.
The abundance of benefits that bifacial solar panels bring to the table as opposed to conventional panels can make this vision a reality very soon.
A new age of solar energy revolution is on the verge to come.
Read The 3 Types of Solar Power System for more solar options for your home or workplace.
