Solar energy is one of the fastest growing renewable energy resources. It is extremely important to improve the reliability and availability of solar energy systems and to further reduce the operation and maintenance (O&M) cost. Solar cells and modules are considered as one of the most critical components in solar energy system because they convert solar energy into electricity. Flaws and damages are inevitable during either the fabrication or the servic. Solar energy is one of the fastest growing renewable energy resources. It is extremely important to improve the reliability and availability of solar energy systems and to further reduce the operation and maintenance (O&M) cost. Solar cells and modules are considered as one of the most critical components in solar energy system because they convert solar energy into electricity. Flaws and damages are inevitable during either the fabrication or the service life of a solar cell or module. Thus, nondestructive inspection, testing and evaluation (NDI, NDT& NDE) for solar cells and modules are required in both manufacturing quality control and in-service inspection. In this work, a fully, in-depth and comprehensive review of NDT&E techniques for Si-based, thin film and multi-junction solar is reported based on an orderly and concise literature survey. Firstly, the developments and case comparison studies of electromagnetic, sonic and ultrasonic, optical, thermal, near-infrared, terahertz and mechanical test NDT&E for Si-based solar cells especially in the last three years are reviewed in detail. Next, the developments of NDT&E methods for film and multi-junction solar cells are also reviewed. After that, the strengths and limitations of these NDI and NDT techniques are concluded through comparison studies. Analytic hierarchy process (AHP) is used to compare 7 kinds of NDT methods which include photoluminescence (PL), electroluminescence (EL), illuminated lock-in thermography (ILIT), dark lock-in thermography (DLIT), res. AEAcoustic emissionAHPAnalytic hierarchy processCCDCharge coupled deviceCIGSCopper-indium-gallium-selenideDLITDark lock-in thermographyEBICSolar cellThin filmMulti-junctionNondestructive testing and evaluationWith the gradual warming of the global climate, the increasingly serious environmental pollution and the depletion of fossil energy, it is urgent to find efficient and practical renewable energy. Solar energy is one of the fastest growing renewable energy resources, and it is going to have remarkable share in the energy market. With the growing interest to quality and cost problems, much attention has been devoted to the development of reliability based maintenance or condition based maintenance. Solar cells and modules are considered as one of the most critical components in solar energy system because they convert solar energy into useful power. On the one hand, some flaws may occur in the manufacture process of cells. On the other hand, solar cells are facing harsh and complex service environment and could be damaged by moisture absorption, sleet, ultraviolet irradiation, atmospheric corrosion, fatigue, or lightning strikes etc. Thus, a lot of flaws and damages may be sustained by solar cells and modules. Fig. 1(a) shows the monocrystalline silicon solar cell with some defects; Fig. 1(b) shows photovoltaic module failure in large areas; Fig. 1(c) shows the hot spots of in-service PV modules; Fig. 1(d) shows damaged photovoltaic modules in the explosion of PV plant.Aside from developing more advanced cells and modules to improve the availability, another effective way would be to apply reliable and cost-effective. Si-based solar cells mainly refer to monocrystalline silicon, amorphous silicon and polycrystalline silicon solar cells. In mass and industrial production, monocrystalline silicon solar cells have advantages of the highest conversion efficiency, being the most mature technology and with high reliability. In the process of research & development, ma.
