The solar panel technology is advancing rapidly. With every new model iterations – mono PERC, half-cell etc. – the industry is trying to increase the efficiency and improve low-light performance. However, bifacial panels provides a huge jump in efficiency due to its inherent design principle of generating power from both sides of the panel. Longi Solar is one of the companies who is at the forefront of this technology.
Longi is one of the biggest PV module manufacturer, recently overtaking Jinko to become the top tier-1 panel brand. As of Q4 2019, they are the first solar company to spend over US$ 1 billion in PV module research, innovation and manufacturing related expenses. They have also recently made an announcement about their planned production capacity increase from 45 to 60 Gwp by next year. Recently, along with TUV Rheinland (A German testing institute), Longi recorded the performance of its bifacial modules. These panels were installed in Chennai, India in September 2018. This region of the Indian sub-continent is known for consistently higher solar irradiation throughout the year, similar to the Australian outbacks. The test installation constitutes axially mounted monofacial PERC and p-type Bifacial PERC from Longi; and n-type bifacial PERC (Frameless) and multi crystalline black silicon modules from another manufacturer. The panels had a reflective white gravel surface beneath them.
Six month results showed that the bifacial modules provided over 20% consistent energy yield compared to their single-sided counterparts. The n-type bifacial modules provided better efficiency than p-type variant due the lack of frame, which leads to minimal shading. On the other hand, bifacials with frame can offer better constructional rigidity and long-term reliability. The energy yield from bifacial modules increased with the availability of scattered sunlight. However, their energy gains remained consistent during the test period.
Prior to the large-scale adoption and deployment of bifacial systems, more testing and monitoring from independent organizations and manufacturers can showcase the reliability and dependability proof that the industry requires for this technology