Engineering success: Silicon cell produces 4.73 Watt peak
Bosch Solar Energy achieves a world record
- Efficiency of 19.6 percent for large-area 156 x 156 mm silicon solar cells
- Measurement independently confirmed by the Fraunhofer ISE CalLab
- Higher energy yield due to improved low-light performance and a favorable temperature coefficient
Erfurt/Arnstadt – Bosch Solar Energy AG has achieved a new record for large-area PERC solar cells on p-type wafers which are widely used in the industry. The independent calibration laboratory at Fraunhofer Institute for Solar Energy Systems has confirmed that a degree of efficiency of 19.6 percent has been reached for monocrystalline solar cells with screen-printed metallization in 156 x 156 mm format. This makes these high-performance cells to reach a record output of 4.73 Watt peak. In general, silicon based screen printed solar cells achieve efficiencies of 17 to 18.5 percent.
PERC stands for “Passivated Emitter and Rear Cell”. The rear side of these solar cells is coated with a dielectric and a metal layer and equipped with point contacts. This new structure improves the solar cells’ optical and electrical properties. The incident light is reflected on the cell’s reflective rear side, thus enabling the emitter to convert more light into electricity. The front side of the high-performance cell was also optimized. For this, Bosch Solar Energy has already presented the concept at the 25th EUPVSEC in September 2010 in Valencia.
The altered cell concept also improves the cell’s performance under weak lighting conditions. Due to the high open-circuit voltage, the temperature coefficient is noticeably better than that of standard solar cells. Hence, solar modules with these cells yield proportionately more output under weak light incidence and increased ambient temperatures, thus increasing the annual energy yield.
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Source: www.bosch-solarenergy.com