Understanding Cell Efficiency
Solar PV Cells are thin slices of silicon, that convert the light that falls onto them into electrical power. Read more here.
The PV cell's I-V (Current- Voltage) characterization is one of the critical measurements from which we can obtain solar cell efficiency and other electrical properties.
These measurements are recorded as an I-V curve.
The I-V measurement of PV cells is conducted using an artificial light source with a spectral content similar to sunlight. This means that for a more accurate reading, the light source used to measure the electrical characteristics of a PV Cell, should emit light of wavelengths similar to the sun!
Hence, this device is called a Sun-Simulator.
These measurements are carried out at a controlled temperature of 25 °C.
The efficiency of a solar cell ratio between the maximum power output of the solar cell to the incident power of sunlight falling upon the cell.
Efficiency is the most commonly used parameter to compare the performance of one solar cell to another.
The wafer quality is key to achieving better efficiency in a solar cell.
The efficiency of a cell also depends on the solar spectrum, the intensity of sunlight, and the temperature of the solar cell.
The efficiency of multi-crystalline solar cells is lower than mono-crystalline silicon solar cells due to the presence of impurities and extended defects such as grain boundaries and dislocations.
Data & Image Credits : RenewSys
Video Credit: Owens Design Inc.