It's a thin slice of crystalline silicon, typically measuring around 0. 20 mm thick, that converts sunlight into electricity using the photovoltaic effect. Dozens of these cells are connected in series and parallel circuits to form a module, which you see on rooftops or in solar. . A solar cell (also called a photovoltaic cell) is the fundamental building block of a solar panel. 7mm (M4), 166mm (M6). . In order to increase the power of solar panels and reduce the cost of solar panels, the silicon wafer industry has been driven to continuously expand the size of silicon wafers, from M2, M4, G1, M6, M10, and finally to M12 (G12) and M10+. Before year 2010, monocrystalline silicon wafers were. . M1, M2, M3, M4, M5, M6, and M12 are standard different wafer sizes used in the solar cell production process Why is Wafer Size Matter? The demand for wafers has exponentially increased over the past two decades due to the increase in the production and sale of PV systems, smartphones and more. Also for manufacturers from South Korea and Japan. Thus the first 156 watt module, manufactured by BP, was also based on this 125 x. . Panel “Size” vs Physical Dimensions: The most critical distinction for homeowners is that solar panel “size” refers to electrical output (measured in watts), not physical measurements. A 400W panel has the same physical footprint whether it produces 350W or 450W – the difference lies in cell. .