PROS AND CONS OF MONO CRYSTALLINE AND POLY CRYSTALLINE SOLAR PANELS

Solar PV market is predominantly using Mono crystalline and Poly crystalline solar panels. As the name suggest, Mono crystalline cells are made from a single continuous crystal structure. Mono crystalline panels can be identified visually as the cells appear as a single flat colour, generally dark black.

The solar cell under a Mono crystalline technology are made through czochralski method wherein a silicon crystal seed is placed in a vat of molten silicon. The seed is then slowly drown up with the molten silicon forming a solid crystal structure around the seed known as ingot. The ingot of solid crystal silicon is then formed in such a way that the ingot of the solid crystal silicon is then cut into silicon wafers and these wafers are made into solar cells. The czochralski process results in large cylindrical ingots. Four sides are cut out of the ingots to make silicon wafers. A significant amount of the original silicon ends up as waste.

In case of Poly crystalline solar cells, the silicon crystal seeds up with vat of silicon crystals seed placed in a vat of molten silicon. However, rather than draw a single crystal seeds up with Mono crystalline, a vat of silicon is simply allowed to cool. This is what forms distinctive edges and grains of solar cells. Poly crystalline cells are typically considered as less efficiency cells as compared to Mono crystalline cells. However, due to their cheaper production methods and less wastage of silicon during the production process. The Poly crystalline technology still dominate technology in the market. Typically, Poly crystalline cells are made of 60 cell or 72 cells in a module.

The advantages of Mono crystalline cells over Poly crystalline cells are as follows:

• Mono crystalline solar panels have higher efficiency as compared to Poly crystalline. Typically, the Mono crystalline panels have about 22% efficiency while Poly crystalline modules have about 20% efficiency.
• Mono crystalline solar panels are space efficient as their individual solar panel output is more than the Poly crystalline solar panels. Typically, Mono crystalline solar panel produce about 380-400 Wp power output (72 cells solar panel) while a Poly crystalline solar panel produce about 33o-340 Wp power output.
• Mono crystalline solar panels are expected to be performing more efficiently in warm weather. With increase in the operating temperature of solar panels, the degradation in power output is less severe in case of Mono crystalline as compared to Poly crystalline solar panel.