# Progress in Improving Photovoltaics Longevity
## 4 Results
### PV Longevity Improvement
#### 4.4.2 Mitigation Strategies
In traditional c-Si solar cell technology, the utilization of Si with a high purity index, thereby lowering defects and impurity concentration, can reduce the susceptibility to PID. A well-promising technology with great potential for constant improvement is the thin-film PV [179]. This field includes CIGS and CdTe materials, which have a dense structure and are suggested for mitigating burn-in effects. * **Extensive testing and failure analysis**. Extensive testing and failure analysis [180] are an integral part of the vision to expand the lifespan of PV modules and can be carried out by a combination of different methods and practices. Accelerated testing aims to investigate long-term exposure to scaled stress conditions, such as high humidity condensation, high temperature, or high percentage of UV irradiance. Typical aspects of this method comprise damp heat testing, interaction with increased UV radiation, thermal cycling, and mechanical load testing. In the case of stressful situations that are difficult to simulate, such as in installation areas with different climates, field testing is employed, and perpetual inspection of the module is carried out. This method offers a deep insight into the effect of long-term operation on the PV module's performance and confirms the findings of the laboratory tests. A typical aspect of failure analysis is root cause analysis [181; 182]. This method is used in the case of existing damage and failures and is intended for the method examination and identification of the responsible cause. By studying damaged connections, malfunctioning materials, and faulty interfaces, both on a macroscopic and microscopic scale, the precise reasons for degradation and possible defects can be detected. Additionally, failure analysis is a valuable tool for mapping and recognizing imprints of specific degradation mechanisms, such as LID, TID, and PID. * **Effective heat dissipation**. The genuine challenge for the prosperity and advancement of PV technology is ensuring effective heat dissipation mechanisms. During operation, elevated temperatures within the module are raised, causing a drop in its power output and accelerating the degradation of its components and materials. These detrimental effects of high temperatures can drastically lower its lifespan. The development and subsequent establishment of mitigation techniques that guarantee effective heat management is crucial for the longevity of PV modules. Toward this purpose, different cooling technologies have emerged and are constantly being improved--passive cooling, active cooling, and hybrid cooling methods--which are a combination of the two previous ones. Passive cooling, which is mainly applied in large-scale installations, is an energy-beneficial system, as it does not require additional energy. In this technique, heat dissipation is based on the natural transfer of the stored heat to the ambient via conduction, convection, radiation, and evaporation. This process is significantly facilitated by the quality and the properties of the module's overall design. For example, bifacial modules, which ensure unobstructed air circulation, or modules with advanced airflow systems can provide useful guidelines for the improvements of passive cooling technology. [PERSON] et al. presented interesting experimental results of a comparative analysis among various passive cooling methods, including greenhouse cooling, plant cooling, and a combination of the two aforementioned phase change materials, which are cooling and coirp with [183]. Based on their outcomes, the achieved reduction in temperature is not strongly related to an increase in power and efficiency for all the techniques. They suggest that the selection of the appropriate cooling method depends on the environmental and climate conditions. [PERSON] et al., in their recent work, delve into a thorough study of the available literature regarding passive cooling methods and devices, summarizing their advantages and underlining the remaining research gaps [184].