a method developed at colorado state university for high efficiency, low cost solar technology will get mass produced by the end of 2007 by ava solar at a current cost below €0.7 / watt.
since 1954, photovoltaic solar cells have progressed from early cells priced at €1065 per watt to modern cells that cost around €2.13 per watt.
read more. read a wiki on solar power.