In Spain, the necessary growth containment of greenhouse gas
emissions set by the Kyoto Protocol [2] and, the compliance of the
objective stated in the White Book of the European Union [3],
were the main reasons why the so-called Plan of Promotion of the
Renewable Energies (PLAFER) [4] was created in order to encourage the use of renewable energy. Among the different types of
renewable energy, photovoltaic solar energy is proving reliable
and, although it has not reached sufficient maturity, significant
efforts are being made in technology research pointing toward
lower manufacturing costs and higher efficiencies [5,6].