Amorphous Solar Cells
The efficiency of amorphous solar panels is not as high as those made from individual solar cells, although this has improved over recent years to the point where they can be seen as a practical alternative to panels made with crystalline cells. Their great advantage lies in their relatively low cost per Watt of power generated. This can be offset, however, by their lower power density; more panels are needed for the same power output and therefore more space is taken up.
Crystalline Solar Cells
Although the theoretical efficiency of monocrystalline cells is slightly higher than that of polycrystalline cells, there is little practical difference in performance. Crystalline cells generally have a longer lifetime than the amorphous variety.