Panasonic Achieves World’s Highest Output Temperature Coefficient of Solar Panel
Panasonic has achieved an output temperature coefficient of -0.258%/°C with a silicon-based solar panel.
The coefficient is the world’s highest level for a mass-produced solar panel. This time, Panasonic improved output temperature coefficient by 0.032 points (from -0.29%/°C) by making improvements to the “hetero junction technology,” which is a characteristic of the company’s “HIT” solar panel.
The conversion efficiency and output of a solar panel (module) consisting of solar cells lower when the temperature rises. Output temperature coefficient is an index of the output reduction. The output temperature coefficient of a commonly-used silicon-based solar cell is about -0.50%/°C (the conversion efficiency lowers by 0.50% when the module temperature rises by 1°C).
For example, at the expected module temperature in summer (75°C), the conversion efficiency lowers by 25%, compared with the efficiency with a module temperature of 25°C. On the other hand, the conversion efficiency of the new module lowers only by about 12.5% due to the improved output temperature coefficient, Panasonic said.
The hetero junction technology, which Panasonic applies to solar cell modules, forms a junction by covering the surface of a crystalline silicon substrate with an amorphous silicon film. It features an excellent passivation function that compensates for many faults near the surface of a silicon substrate. The technologies used for improving output temperature coefficient was first introduced for production in April 2016.