This production technique sprays the silicon onto a base as a thin film. It is a very new technique, so its 20 year performance can only be estimated! One company guarantees less than 20% degradation over 20 years, which compares with 10% for the above 3 types of panel.

The production process is more energy efficient than any of the other panel types, so the cells are typically cheaper for the same rated power. But they are only 5-7% efficient so they are typically nearly twice the size, so you need a biggish roof!