Sample Technology Paper on Bifacial Solar Panels

Abstract

Bifacial solar panel allows the light on the front and on the back which enables the panel to generate more power. The traditional solar panel can only benefit with the light from the front of the panel. The bifacial solar panel has high efficiency due to the single-crystal silicon cell nature, but traditional solar panel uses numerous silicon fragments which are melted together. Bifacial solar panels have a dual-panel of glass or reflective backsheet however Traditional solar panels use the opaque back sheet. High durability and efficiency are notable characteristics of bifacial solar panel however they are more costly than traditional ones. Social constraint associated with the bifacial solar panel is that they are unpopular to residential areas. Bifacial solar panels are expensive in nature which creates an economic restriction. Electric shock, solar falls, and arch flash burn are health and safety constraints. Maintenance costs associated with perimeters, geographical location, weather conditions, and general maintenance pose a sustainability challenge for bifacial solar panels. Unethical professional also poses as challenging due to the acceleration of prices for installation and maintenance.

Keywords: Bifacial solar panels, Traditional solar panels, light

Bifacial Solar Panels

Introduction

The bifacial solar panels have a front surface similar to an ordinary standard solar cells, where the rear surface is the only difference in terms of the structure. Bifacial solar panels are useful in a residential application such as some ground-mounted systems and pergolas. Bifacial panels are commonly used in commercial areas, since they are more efficient and durable however the buying price and installation fee is high. The bifacial panel has the advantage of absorbing the light from the front and back respectively. Bifacial are suggested for commercial purposes due to their high performance and durability. Traditional PV solar access light only from the front which is a limitation compared to bifacial. Accordingly, Monocrystalline cells are associated with bifacial solar modules, while polycrystalline cells are associated with traditional solar panels.

The Difference in Structure between Bifacial and Traditional Solar Panels

The technical term that refer to bifacial solar panel is monocrystalline, while the term polycrystalline also means traditional solar panel (Miller et al., 2019). Both polycrystalline and monocrystalline solar panels do the same activity in solar PV systems (Tyagi et al., 2019). They both have the same function to absorb the light and generate electricity in residential nd commercial places. Both bifacial and traditional panels consist of silicon (Tian, Boschloo, & Hagfeldt, 2018). The difference between bifacial and traditional solar panels is the silicon cell (Sabater et al., 2018).In traditional one, fragments of silicon are melted together. Nevertheless, monocrystalline is made of a single cell crystal that produces more energy since the movement of electrons.

Monocrystalline Solar Panels

The common benefits of the monocrystalline solar panels are sleeker aesthetic and higher efficiencies. Monocrystalline solar panel is made after bars of silicon are formed and designed into wafers (Pandikumar & Ramaraj, 2018). These kind of solar modules are known as monocrystalline since they are made from single-crystal silicon. The cells are made from single-crystal silicon, and this creates more room for electrons to move freely which results to an easy flow of electricity (Eltamaly & Abdelaziz, 2019). Hence, the efficient aspect of bifacial solar makes it more popular to commercial places than the traditional one.

Polycrystalline Solar Panels

These solar panels are cheap and readily available in the market and cost-effective when it comes to installation, although have low efficiency. Furthermore, polycrystalline solar panels are blue in colour, while bifacial solar panels are black in colour (Tyagi et al., 2019). Traditional panels consist of numerous fragments of silicon that forms wafers. Polycrystalline panels are also known as multi-crystalline (Conibeer & Willoughby, 2016). In polycrystalline, electrons do not move freely since there are many silicon cells in the system (Fedorenko et al., 2019). As a proof, low efficiency rate is weakness compared to bifacial one.

Difference in Functionality between Bifacial and Traditional solar panels

Bifacial solar panel has the ability to absorb the light from both sides and even function with slightest light available, this aspect explains the reason why it is popular in commercial places (Conibeer & Willoughby, 2016). Traditional solar panels lost a lot of potential energy during the transfer when the lights hit the back of the solar panel (Singh et al., 2017). Many bifacial solar panels operates with monocrystalline cells that creates a pathway for electrons to freely move and generate more electricity (Gençer et al., 2017). The light is absorbed on both back and front side of the panel’s cells, where the overall efficiency of the bifacial solar cells can be up to 30% greater than the traditional one (Tian, Boschloo, & Hagfeldt, 2018). As a consequence, the exact amount of energy the cells can absorb varies depending on the surface the panel is installed on. Bifacial absorbs a lot energy since they the light is allowed on both sides of the solar panel.

Bifacial Solar Panels

In comparison, bifacial solar panels have a dual-panel of glass or reflective back sheet but traditional one have opaque backing. The frameless aspect assist in reducing potential induced degradation (Sabater et al., 2018). The bifacial cells contain selective-area metallization schemes which allow the light between the metalized places, rather than conventional metal collectors as experienced with the monoficial panels (Pandikumar & Ramaraj, 2018). Vertical or horizontal way are installation methods for bifacial solar panel which helps to utilize the light from all sides. In the case of a vertical angle, the solar cells can be tilted at any angle to achieve the maximum amount of lights from the east and west in the morning to achieve the desired amount of energy (Sabater et al., 2018). Horizontally, all light reflected on the surface reaches the cell through the back of the solar panel.

Traditional Solar Panels

The modules are placed in a periodic array to build a solar panel (Pandikumar & Ramaraj, 2018). The solar pane can absorb the light according to photovoltaic cells available on a panel. The more cells in a panel the more power is produced in solar panel. The efficiency of the traditional cells is limited, as a result of the junction. Many traditional solar panel are used in residential places since their power is limited during the process of absorbing the energy. (Eltamaly & Abdelaziz, 2019). The solar panel has limited efficiency, however, they are cheaper compared to bifacial one.

Moreover, traditional solar panels can only receive the light from one side, which indicates that the efficiency is determined by the position of the solar panel (Singh et al., 2017). The positioning of the solar system can affect the sunlight absorbed during the day. Traditional solar panels waste a lot of light unlike bifacial which utilizes from both front and back to generate electricity. The installation of traditional solar panels are carried on the rooftops of the houses to save space and avoid shades, which may affect the light to be absorbed (Gençer et al., 2017). It would be useless to put bifacial solar panels on the rooftop of the house since it would limit the reflection of the light.

Benefits of bifacial solar panels. The efficiency associated bifacial solar panels is crucial for generating more power (Sabater et al., 2018). The bifacial solar modules ensure that it has captured the indirect sunlight rays from the rear of the solar cells, which helps in achieving the higher efficiency, unlike the traditional solar panels, which only absorbs the sunlight from the front of the panel (Tyagi et al., 2019). Moreover, bifacial is made of a single silicon cell which makes the electrons to move freely which translates to more production of electricity (Conibeer & Willoughby, 2016). Therefore, the solar panel efficiency increases which leads to increase in the output, which translates to more energy and power.

Durability. The durability aspect makes the bifacial panel to be a priority to many people who want a solar that can serve for long. The durability is vital aspect since all clients love the solar that is worth their money. Embedding of solar photovoltaic cells in glass assists in protecting the bifacial panel from environmental and mechanical damages, making it durable (Pandikumar & Ramaraj, 2018). For instance, the bifacial solar modules are intact, which helps to persevere abnormal weather conditions (Tyagi et al., 2019). The panel is designed to be able to survive wind, rain, and many other environmental occurrences. During installation, if something mechanical happens, such as falling on the ground, it has a high chance of functioning since cells are protected by tough glass. Appropriately, the embedding of solar cells defines its durability aspect.

The bifacial solar panels are able to capture little light available and convert it to electricity. When the sunlight hits the solar section, the light passes the solar panel surfaces because of the glass panel (Pandikumar & Ramaraj, 2018). Glass frame allows the light into the back of the panels instead of the traditional opaque backsheet (Gençer, 2017). The bifacial solar panel can be installed in a vertical way in an east and west direction to aim the sunlight (Tyagi et al., 2019). The significance of the vertical installation allows the bifacial panels to have two production time in a day (Miller et al., 2019). The first peak is in the morning and the second one is in the evening. Bifacial are more helpful since the panel can absorb light from the front and back. Additionally, the panel have the ability to reflect light during morning time and evening since the two sides allows the light to penetrate well.

Potential benefits of bifacial solar panel. A crucial potential benefit is growing investment in the solar energy to favour growth in the Asia Pacific and the whole world at general. The bifacial solar market is divided by America, Asia, Africa and Middle East. Among all these areas, Asia may control the international bifacial solar modules in the future (Tyagi et al., 2019). The domination may occur in nations such as Japan, China, and India, which are heavily investing in research and development of the bifacial energy. These countries have the potential to hold the most massive installed solar panels (Eltamaly & Abdelaziz, 2019). America and Europe are anticipated to follow the same route of Asia pacific in the forecast of 2020-2026 (Tyagi et al., 2019). Investors have realized the potential of the solar industry and they are paying attention closely. Additionally, Africa and the Middle East are projected to acquire the share of a bifacial solar panel by 2026.

Increasing demand for electricity to fuel industrial and commercial areas will lead to growth in the bifacial solar panel market. Bifacial solar panels are popular and beneficial for commercial purposes. In these areas of concern, the commercial market is projected to have an impact on the global market due to the increase in the demand for electricity (Conibeer & Willoughby, 2016). Furthermore, the industrial sector will proliferate due to the need of solar-based electricity (Gençer, 2017). For that reason, manufacturers are working towards adding more value to the solar panels such as increasing efficiency. Another significant area of concern that is being addressed is the issue of making the bifacial solar panels affordable to everyone.

Industrial development. There is more production of bifacial solar panels since the demand has risen from the commercial sectors (Gençer, 2017). The increase in the usage and adoption of technologies have helped the investors to acquire revenue from the bifacial solar panel for years, and the market is expected to expand in the future (Tyagi et al., 2019). The use of bifacial solar panel has helped numerous market players to access an extensive coverage in terms of clients on a global scale (Miller et al., 2019). Investors operating in bifacial solar panels have started to sign agreements and contracts to create a competitive market for bifacial solar panels where they can be supplied on a large scale on fair price.

Longi Solar Company, headquartered in China, signed a contract with Mitchell County, Georgia, to supply bifacial solar panels (Tian, Boschloo, & Hagfeldt, 2018).  The Georgia solar project is the largest in U.S., which has a capacity of 224MW. The completion of Southern Oak Solar Project is due before the end of 2019 as planned and stated in the agreement (Fedorenko et al., 2019). The project will benefit 30,000 houses where they will be supplied with clean electricity. The Southern Oak Solar Project, with a capacity of 224MW, is expected to put Longi Solar Company on another level (Eltamaly & Abdelaziz, 2019).As a consequence, the Longi Solar Company will grow as well as the bifacial solar industry.

Bifacial solar panel has several disadvantages. The cost of purchasing is high. The bifacial solar is costly since they possess a double glass and they are more advanced than traditional solar panels (Kang, Kim, & Kim, 2016). For instance, the cost of the solar panel in the ALTE store website for the bifacial solar panel named Solar World Sun Module with 260W IS $249 per panel (Tian, Boschloo, & Hagfeldt, 2018). For traditional solar panel called Solar World Sun Module with 260W IS $196 per panel. Appropriately, the cost of bifacial solar panel discourages a potential customer since it is expensive to purchase.

Huge installation cost.  Another significant disadvantage is the huge installation cost. The bifacial solar panel will perform poorly on the house’s roof since there will be no reflection (Fedorenko et al., 2019). This translates that bifacial solar panels require more finance to install than the traditional solar panels since a significant space is required (Pandikumar & Ramaraj, 2018). Additionally, the installation of bifacial solar panels requires a more trained professional to align the solar in the desired angle (Eltamaly & Abdelaziz, 2019). For example, the bifacial solar panel is mostly installed in a vertical way, which takes a lot of time to set, which also translates to more funds spend on the project. Accordingly, bifacial solar installation requires a lot of human resources and time.

Constraints of bifacial solar panels. Social constraints, the primary social constraint of the bifacial solar panel is that it is commonly used on commercial bases (Sabater et al., 2018). This fact indicates that many people may be using the traditional solar panel on bases that bifacial are related to big companies and institutions (Conibeer & Willoughby, 2016). Many people who use solar are not socially embedded with bifacial since residential consumers commonly have an ordinary solar system that is installed on the roof of the building (Tyagi et al., 2019). As a proof, the market players in the industry have an extra task to campaign for bifacial to enable them to reach potential residential costumers on a global scale (Gençer, 2017). As a result, the bifacial solar panel is mostly identified with commercial sectors, thus having a limitation on the residential part, which also has many potential customers.

Economic constraints. The bifacial solar panel is expensive, which limits an ordinary client despite the huge funds investor’s stake on these projects. Many people consider the price and goes for the traditional solar panel since they perform the same function (Miller et al., 2019). Due to that limitation, companies that manufacture bifacial solar panels may not sell the solar on a large scale despite investing heavily in the production (Eltamaly & Abdelaziz, 2019). An ordinary client will consider purchasing the traditional one rather than bifacial on financial grounds (Gençer, 2017). Appropriately, the high-cost results in economic limitation since investors are not able to profit in less duration since the demand is low, especially in residential areas.

Health and Safety constraint. Bifacial solar panels pose some limitations to the consumers and technicians who operate the system (Sabater et al., 2018). Both consumers and technicians are exposed to potential hazards, which include blast hazards and arc flash burns. The bifacial solar panels pose severe threats to health and safety, such as electric shock, and solar falls (Pandikumar & Ramaraj, 2018). Thermal burn hazards can lead to severe injuries and cause death at any given time (Singh et al., 2017). The health and safety of technicians are at stake when installing the solar panels. Therefore, bifacial solar panels have limitations since they also have a dark side, and there is no 100% guarantee on health and safety. Hence, the safety of person is crucial and cannot be taken for granted.

Sustainability constraints for bifacial solar panels. There are several limitations to the sustainability of bifacial solar panels, such as geographical position. If the land is sloppy, the sustainability and maintenance of the solar panel would be costly since the angle for installation would consume a lot of time and materials than a flat ground (Sabater et al., 2018). The weather condition also poses sustainability constraints since the wind and heavy rain causes damages, which is costly to repair (Singh et al., 2017). There must be a perimeter to keep the solar panels safe. The perimeter also needs to be maintained, which is also costly to sustain (Tian, Boschloo, & Hagfeldt, 2018). Respectively, geographical position, weather conditions, and perimeter maintenance poses sustainability limitations for bifacial solar panels.

Professional and ethical considerations for bifacial solar panels. Professionals who deal with the supply and installation of bifacial solar panels may take advantage and manipulate the customer financially. They may raise the price of installation than the normal rates, which is unethical and unhealthy for the business (Tyagi et al., 2019). Moreover, some of the unethical market players in the solar industry sometimes use quacks to install and maintain the system, which ruins the reputation of the whole industry. The bifacial solar market is expected to supply, install, and maintain the solar panels at a fair price (Kang, Kim, & Kim, 2016). Accordingly, inconsistence installation fees have benefited a few selfish professionals in the market, which is unethical. The unfair prices and unethical professional poses as constraints to the bifacial solar panel industry.

Conclusion

In conclusion, polycrystalline and monocrystalline panels do the similar functions in solar, which is to capturing the slightest light and convert it into electricity. Bars of Silicon are formed and converted to wafers to create Monocrystalline solar panels. Polycrystalline panels are made of silicon, where wafers are formed after several fragments of silicon are melted. Bifacial solar are efficient and durable due to the double glass protecting the cells. Bifacial solar is expensive since they possess a double glass and huge installation cost. Embedding of solar photovoltaic cells in glass assists in protecting the bifacial panel from environmental and mechanical damages. A notable social constraint of the bifacial solar system is that there are not popular with residential areas and costly, which is an economic limitation. Flash burn and electric shock pose a danger to the health and safety of operators. Weather conditions and geographical position poses a challenge in the sustainability of solar panels. Lastly, unethical professionals manipulate customers by elevating prices.

 

References

Conibeer, G., & Willoughby, A. (2016). Solar cell materials: Developing technologies. Chichester (United Kingdom: Wiley.

Eltamaly, A. M., & Abdelaziz, A. Y. (2019). Modern maximum power point tracking techniques for photovoltaic energy systems. Cham, Switzerland: Springer.

Fedorenko, A., Baboli, M. A., Mohseni, P. K., & Hubbard, S. M. (2019). Design and Simulation of the Bifacial III-V-Nanowire-on-Si Solar Cell. MRS Advances4(16), 929-936.

Gençer, E., Miskin, C., Sun, X., Khan, M. R., Bermel, P., Alam, M. A., & Agrawal, R. (2017). Directing solar photons to sustainably meet food, energy, and water needs. Scientific reports7(1), 3133.

Kang, J. G., Kim, J. H., & Kim, J. T. (2016). Design elements and electrical performance of a bifacial BIPV module. International Journal of Photoenergy, 20 16.

Miller, I., Gençer, E., Vogelbaum, H. S., Brown, P. R., Torkamani, S., & O’Sullivan, F. M. (2019). Parametric modeling of life cycle greenhouse gas emissions from photovoltaic power. Applied energy238, 760-774.

Sabater, A. A., Wöhrle, N., Greulich, J. M., Rein, S., & Ramspeck, K. (2018). Impact of bifacial illumination and sorting criteria of bifacial solar cells on module power. In AIP Conference Proceedings (Vol. 1999, No. 1, p. 020004). AIP Publishing.

Singh, J. P., Chai, J., Saw, M. H., & Khoo, Y. S. (2017). Bifacial solar cell measurements under standard test conditions and the impact on cell-to-module loss analysis. Japanese Journal of Applied Physics56(8S2), 08MD04.