What is a polycrystalline panel? It is one of the 3 kinds of photovoltaic panels on the market. It is called polycrystalline because there are several crystals in one cell, as a monocrystalline panel has one crystal only by cell. The quality / price ratio is better for a polycrystalline panel than a monocrystalline panel because even if the performance difference is around 1 or 2 % better for the monocrystalline (it used to be higher but the commercial success of the polycristalline type allowed the technology to improve quickly), whereas the price difference can be quite important with an advantage for a cheaper polycrystalline panel because less complex to build. The third kind of panel is called amorphous. It has several advantages as a great performance in low light, and a conception of thin cells so also very light cells. Nevertheless, the performance with important light is not as good as the two others.