Hot Spot

A hot spot in a photovoltaic system is a localized area within a solar module that exhibits a significantly higher temperature than the rest of the module. This overheating can have various causes, such as:

  • Shading: If part of a solar module is covered by dirt, shade from buildings, trees, or other modules, this can lead to reduced performance in that area. Since the unshaded part of the module continues to produce electricity, the current flows through the shaded area, generating heat there.
  • Microcracks: Microscopic cracks in the solar cells can also lead to hot spots. These cracks impair electrical conductivity and cause a local reduction in performance.
  • Defective Diodes: Bypass diodes protect individual solar cells from overload. If one of these diodes is defective, it can lead to overheating of the affected cell.
  • Manufacturing Errors: Rarely, manufacturing errors during the production of solar modules can lead to hot spots.

Effects of Hot Spots

Hot spots have negative effects on the performance and lifespan of a photovoltaic system:

  • Performance Reduction: The performance of a solar module with a hot spot is lower than that of a fault-free module.
  • Reduced Lifespan: The high temperature in a hot spot accelerates the degradation of the solar cell and can lead to premature failure.
  • Fire Hazard: In rare cases, a hot spot can become so hot that it poses a fire risk.

Prevention and Detection

To avoid or detect hot spots early, the following measures are recommended:

  • Careful Planning and Installation: The photovoltaic system should be installed to minimize shading as much as possible.
  • Regular Cleaning: Solar modules should be regularly cleaned of dirt.
  • High-Quality Modules: Using high-quality solar modules with good cell technology reduces the risk of hot spots.
  • Monitoring Systems: Modern inverters are often equipped with monitoring systems that can detect hot spots early.

Conclusion

Hot spots are a potential problem for photovoltaic systems. However, they can be avoided or detected early through appropriate measures. Regular maintenance and monitoring of the system are essential to ensure optimal performance and a long lifespan.

Relevant Keywords: Solar Module, Solar Cell, Shading, Bypass Diode, Degradation