Considering factors such as solar cell module conversion efficiency, technological level, manufacturing process maturity, and market share, the commonly used module types for large-scale grid-connected photovoltaic power plants can be broadly classified into crystalline silicon modules and amorphous silicon modules. Crystalline silicon modules are further divided into monocrystalline silicon and polycrystalline silicon. Amorphous silicon modules are mainly thin-film modules. Below is a brief analysis of the conversion efficiency of various photovoltaic cell modules:
1. Monocrystalline silicon solar cell modules
Monocrystalline silicon solar modules are currently the most common high-efficiency solar modules on the market. Breakthroughs in the manufacturing processes and technologies of the monocrystalline silicon industry chain result in a more perfect crystal lattice, allowing for better light absorption and higher conversion efficiency. For monocrystalline solar cell modules, LONGi's PERC high-efficiency monocrystalline cells have achieved an efficiency exceeding 23%, setting a world record. Ordinary monocrystalline modules also boast conversion efficiencies above 18%, the highest photoelectric conversion efficiency among all types of solar cells.
With the continuous maturation of technology, the price of monocrystalline modules is now comparable to that of polycrystalline modules. Because monocrystalline silicon is generally encapsulated with tempered glass and waterproof resin, it is robust and durable, with a lifespan typically reaching 20 years and sometimes up to 30 years.
2. Polycrystalline silicon solar cell modules
Compared to monocrystalline silicon cells, polycrystalline silicon cells consist of multiple tiny monocrystalline wafers with numerous grain boundaries and defects. This essentially creates a minority carrier recombination center, thus reducing the conversion efficiency of polycrystalline silicon cells. Currently, the efficiency of polycrystalline cells on conventional production lines is around 16%.
3. Thin-film solar cell modules
After several years of rapid development, the laboratory efficiency of single-junction amorphous silicon thin-film solar cells can reach about 12.7%, the laboratory efficiency of microcrystalline silicon multi-junction solar cells can reach 13.4%, the laboratory photoelectric conversion efficiency of cadmium telluride (CdTe) thin-film solar cells can reach 16%, and the average efficiency of commercially available cells is 8%-10%. The conversion efficiency of copper indium gallium selenide (CIGS) can reach 14%.
However, compared to crystalline silicon modules, the main problem with thin-film solar cell modules is their low photoelectric conversion efficiency, requiring a huge module area to convert the same amount of electrical energy. Furthermore, thin-film modules suffer from poor stability; their energy conversion efficiency changes with irradiation time. These drawbacks are the biggest obstacles to the widespread application of thin-film solar cell modules.
The analysis of the conversion efficiencies of the three main types of photovoltaic modules above clearly shows that crystalline silicon modules have a significantly higher and more stable conversion efficiency than thin-film modules. Monocrystalline silicon modules, in particular, have a significantly higher and more stable conversion efficiency than polycrystalline silicon modules. For the selection of photovoltaic power plant modules, a technical and economic comparative analysis should be conducted based on the specific circumstances of the project to ultimately determine the optimal battery module selection for the specific photovoltaic power plant.
