Mexico. Trina Solar, one of the global leaders in the supply of solar energy solutions, presents its new BIFACIAL MODULE DUOMAX Twin.
Eng. Andrea Pérez de Ramer responsible for marketing and communication for Latin America at Trina Solar, commented: "Our new DUOMAX Twin module converts the light that hits the front and back of the module generating more energy, while traditional solar modules (known as monofacial) only take advantage of the light that hits the front of it. That is, under the same conditions, a bifacial module will produce more energy than a monofacial module. Remember that being able to provide a higher percentage of energy from the back results in savings in the investments made in a photovoltaic project."
The DUOMAX Twin module has been designed to maximize the benefits of the bifacial cell, as it uses heat-reinforced glass to replace the polymer backing sheet used in traditional modules. Glass provides better protection for the cell and improves the long-term performance of the module, while also providing a transparent medium that allows power generation through the back surface. The improved durability of the module is backed by an energy warranty of more than 30 years and a lower annual power degradation rate (0.5%). The back glass layer has the same transmission effect as the front surface, maximizing the energy generated by bifacial cells. All in all, the DUOMAX Twin module generates more power over a longer period of time than a standard module.
The main component of the DUOMAX Twin bifacial module is the bifacial cell, which can absorb sunlight on both sides, and thus convert a greater portion of the available solar energy. Because a bifacial generates power from both sides, issues such as rear shading must be taken into account during installation.
Trina Solar conducted a study, so it recommends installing the bifacial modules as shown in Figure 1, to avoid rear shading and maximize energy production, since, the bifacial module without back shading produced 6.94% more energy than the standard module, compared to 3.89% more energy for the module with rear shading.
We must remember that albedo is defined as the reflectivity behavior of the soil. The albedo of the local environment has an important effect on the energy gain of the DUOMAX Twin modules. As shown in Figure 2, most of the sunlight that reaches the back of the module is reflected from the surrounding ground cover. This albedo can be highly variable, at ~0.10-0.25 for grasslands, ~0.25-0.46 for cement or sand, and ~0.75 0.90 in a snowfield."
In the study that Trina Solar carried out to compare the energy obtained from the DUOMAX Twin bifacial modules in different environments with various levels of albedo, it considered for this test a DUOMAX Twin module against a standard perc monocrystalline monofacial module. Both modules were installed at a fixed inclination of 27°, with the modules at least 0.4m from the ground. Figure 3 shows the extra energy produced by the bifacial module over several sunny days in April. With the fixed tilt installation method, the generation capacity gain gradually increases with increased reflection of the soil surface, with a maximum gain of 24.6% compared to the monofacial module with the white painted background (albedo of 0.75).
Trina also tested the energy gain for the DUOMAX Twin at different irradiation levels. Figure 4 shows the energy gain at different irradiation levels with three different background materials. The results showed that energy gains were proportionally higher at lower irradiation levels. However, it is important to note that most of the energy produced by a solar panel is produced during periods of high irradiation. This means that in absolute terms, most of the energy obtained due to production from the back of the module occurs when the irradiation is equal to or greater than 800 W / m2. These results show that DUOMAX Twin bifacial modules provide significant benefits regardless of local irradiation levels.
Tests conducted by Trina Solar have also shown that using the DUOMAX Twin in a single-axis tracker maximizes energy gains. This is particularly true during the morning and afternoon periods. Trackers provide several benefits to DUOMAX Twin modules, including keeping them at an optimal inclination and height to maximize irradiation on the back side of the module.
From that data, another comparison is highlighted in Figure 5, where it shows the energy gain for a DUOMAX Twin module that was mounted on a single-axis tracker, compared to a monofacial module with a fixed inclination, under a variety of ground cover conditions. The gains are significant regardless of the background, with a maximum gain of 40% with a white background painted with an albedo of 0.75. These results were obtained in several days of high irradiation.
"At Trina Solar before launching a solution for our customers, our engineering team conducts extensive testing so that our customers have the best technology and have the highest efficiency in their photovoltaic projects." Eng. Andrea Pérez de Ramer concluded about the new DUOMAX Twin module that is available for the Mexican market as well as for all countries in Latin America.
