The Bifacial Era: Reliable & Optimal PV Solutions for 2021-22

Technology optimisation is one of the key parameters when it comes to Solar PV. The existing available wafer sizes of 182mm/163.75mm/166mm/210mm can achieve a maximum power class of up to 450Wp-600 Wp with the number of cells as per the conventional design for each module make. The continued shortfall and rising prices of major raw materials during 2020-21, starting with Polysilicon and Glass, has changed the face of the PV industry forcing a shift towards high efficiency, better energy density and lower LCOEs.

Project developers today, consider these as the most critical and important factors while choosing modules, apart from the product and performance warranties. Reliability aspects specific to extended IEC metrics on Thermal Cycle, Damp Heat, Humidity Freeze, LeTID and PID instill higher confidence in advanced Solar PV Products. Jinko’s Tiger and Tiger Pro Series top the charts in the 3rd party reliability reports on all available variants. Tropical Indian climatic conditions standing at an available GHI of 1700-2100 KWh/Sq.mt./Year can benefit both Monofacial and Bifacial variants depending on the location. For GHIs up to 1800 kWh/Sq.mt./Year – Monofacial modules can be utilised with K film or PVDF back sheet option. At GHIs beyond that value, Bifacial modules with PVF composite 3-layer back sheet will have higher reliability.  Bifacial Technology Modules have the advantage of absorbing both global horizontal irradiation on the front side of the module and diffused/reflected irradiation on the rear side of the module.

Depending on the type of installation, location and albedo factor - the range of gain in specific energy yield varies and is higher than that from Monofacial modules for a particular location. JinkoSolar has done an analysis with all possible ground textures at our Haining factory in China. We have observed that the gain in energy with Bifacial modules can go up to 22% and the same has been ratified by 3rd party agencies.

Tiger Pro Bifacial with Transparent back sheet design has a product warranty of 30 years due to the high-reliability characteristics of the materials being used - POE as encapsulant and PVF in the form of Tedlar-based back sheet. This composition is more sophisticated in comparison to normal encapsulant and back sheets. This optimizes performance and yield improving project CAPEX and OPEX calculations which ultimately results in lower LCOEs. Reduced linear degradation in Bifacial modules is another inherent advantage over Monofacial modules. This implies higher specific energy yield in any given year during the life of the plant.  

Bifacial technologies are getting widespread acceptance in projects across the globe due to these added advantages which improve the overall project economics. It is expected that Bifacial module installations will grow multiple folds in the near future and capture a majority of the market share by 2025. Tiger or Tiger Pro Bifacial Modules, with power class ranging from 460-585 Wp, exhibit higher power/energy densities on surfaces that have low soil moisture content. This in turn increases the reflectivity sensitivities of the soil (surface) enabling the module to produce more energy from the rear side.

- Sai Charan Kuppili, Technical Director, JinkoSolar