Impact of Temperature on Solar Panel Efficiency
Temperature has a significant impact on solar panel efficiency, affecting both the voltage and current produced by the panels.
Effects of High Temperatures
- Efficiency Reduction: As temperature increases, the efficiency of solar panels decreases. For every degree Celsius above 25°C (77°F), a typical solar panel may lose 0.3% to 0.5% of its efficiency. This reduction is more pronounced in hot environments, where panel temperatures can reach as high as 60°C (140°F), resulting in a 10-15% decrease in efficiency.
- Open-Circuit Voltage Decrease: High temperatures reduce the open-circuit voltage (Voc) of solar cells, which is a major factor in the overall efficiency decline. The Voc typically decreases by about 2.2 mV per °C for silicon-based cells.
- Short-Circuit Current Increase: While the short-circuit current (Isc) increases slightly with rising temperatures, this effect is minimal compared to the decrease in Voc.
- Increased Recombination: Higher temperatures lead to increased recombination rates, where electrons and holes recombine instead of contributing to the electrical current, further reducing efficiency.
Effects of Low Temperatures
- Efficiency Increase: In colder conditions, solar panels can operate above their rated efficiency. At temperatures around 0°C (32°F), panels might produce 5-7% more power than their rated output.
- Optimal Performance: The optimal operating temperature for solar panels is generally considered to be around 25°C (77°F). In very cold conditions, while efficiency may increase, other factors like reduced sunlight hours and potential snow cover can impact overall energy production.
Strategies for Mitigating Temperature Effects
- Cooling Techniques: Active cooling systems or passive ventilation can help maintain optimal temperatures and reduce efficiency losses.
- Panel Selection: Choosing panels with low temperature coefficients can minimize the negative impact of high temperatures.
- Installation Design: Proper installation and spacing to facilitate airflow can reduce panel temperatures.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/what-is-the-impact-of-temperature-on-solar-panel-efficiency/
