When it comes to photovoltaic panels, there are two widely used types: monocrystalline and polycrystalline.
In short, in monocrystalline panels a photovoltaic cell consists of a single high purity silicon crystal. In polycrystalline, the cells are made of polycrystalline silicon and include several crystals.
Monocrystalline photovoltaic panels have a higher efficiency than polycrystalline ones and produce more energy in cloudy weather. However, they lose efficiency as the temperature increases. Read more about these conventional types in this article.
Tough and cheap, but less efficient
Thin-film panels work in a similar way to monocrystalline or polycrystalline panels and use the full photovoltaic effect. In this case, however, the panels are very light and flexible because they do not contain silicon crystals. They are composed of multiple thin layers of photovoltaic materials, which can be copper indium, cadmium-telluride, gallium, amorphous (non-crystalline) silicon or selenium. The panels are constructed by depositing very thin layers of photovoltaic semiconductor materials on a support material such as glass or plastic.
These layers are sometimes several hundred times thinner than those in ordinary panels. In thin-film panels, each cell has three parts: photovoltaic material, electrically conductive layer and a protective layer.
Also read: Green energy: Don’t install your solar panel, wind turbine or micro-hydropower plant without this item!
Being lightweight, flexible and durable, these panels are used in mobile energy generation systems (ideal for yachts, campers, solar electric cars) or in areas where the weather is not mild (hail falls, storms, heavy snow, etc.).
Bag equipped with panels
Although more durable and cheaper than monocrystalline and polycrystalline panels, thin-film devices are less efficient and have lower power.
Thin-film models have a maximum efficiency of 18% (this indicator ranges from 7 – 18% for commercially available models). By comparison, monocrystalline panels achieve 25% efficiency, and most commercially available models are in the 18 – 22% range.
Furthermore, tests have shown that thin-film panels have a lifespan several years shorter than conventional panels.
Photo: Profimedia Images
Sources: Ases.org, CNET