Published in "Edilizia e Territorio" issue #4 - Il Sole 24 Ore, Italy - Jan 29-Feb 03 2007

By Cecilia Cecchini - Translated by Elena Savona

 The operating principle of photovoltaic cells – the basic components of a solar energy plant – is based on the ability of certain semiconductor materials to generate electricity when exposed to solar radiation. Silicon, the material most commonly used for this application, can be used to produce three types of cells: single crystal cells, the most common and efficient but also the most expensive due to a cost-intensive manufacturing process; multicrystalline cells, which are less efficient; and amorphous cells, the least expensive but also the least efficient.

The main barrier to widespread adoption of photovoltaic panels is the high cost due not only to market-driven dynamics, but also to manufacturing issues related to the use of silicon, an expensive material whose manufacture requires several processing steps.  In addition, the increased silicon cell demand of the last few years – that will predictably continue at exponential rate - has started to raise raw material supply issues.