There are three generations of technology in the solar PV market. The 1st generation (Gen 1.0) uses poly silicon as feedstock and has been in existence for 50 years. Thick crystalline silicon cells and modules, which include single crystal and poly crystal, cast silicon and ribbon silicon, account for 82% of cells production.
The 2nd generation (Gen 2.0) consists of thin-film cells and modules made from a number of layers of photosensitive materials, of which there are three types, all with active layers in the thickness range of 1-10 microns, and all are capable of manufacture in large volume at low cost. The three types are the A-Si – amorphous silicon cell, the CIS – copper indium diselenide / cadmium sulphide heterojunction cell, and the CdTe – cadmium telluride / cadmium sulphide heterojunction cell. Thin films use much less silicon, only a thin film, or in some cases, none at all. Of the technologies cadmium telluride has the most potential due to its lower cost for cells and utility scale systems.
Third generation PV (Gen 3.0) is very much in its infancy and leaves the traditional semiconductor space altogether. Prototypes that produce electricity at relatively low conversion efficiencies are available, and solar cells printed on plastic or glass using organic materials has been cultivated by some start-ups. Dyesol is one of the most promising: the company debut in top five Bloomberg New Energy Finance New Energy Pioneers in 2009.
Inverter shortages have been reported at the end of 2009 and moving into 2010. Manufacturers reduced capacity in 2009 due to declining demand from the electronics and solar sector, and as the market has picked up inverter manufacturers have been unable to keep up with demand. Waiting times of up to 30 weeks have been reported by some invert manufacturers.