6. Photovoltaics (PV)

During the last 20 years, both the photovoltaic (PV) cumulative installed power and the annual electricity production have increased at an annual rate of about 40 %, resulting in an estimated 67 GW cumulative capacity in 2011. This tremendous growth has been mainly a consequence of the continuous decrease of the cost of solar systems, 75 % in the last 3 years. Therefore, depending on the intensity of the solar resource, the PV electricity is reaching grid parity in many regions of the world. In this chapter, we make a grid parity study of PV and the efficiency of the different types of solar cells. We describe their evolution from the first-generation ones, produced from crystalline silicon, to the thin film or second-generation cells, which make use of much smaller quantities of semiconductor materials: CdTe, CIGS, amorphous-Si, etc. The evolution to the less mature third-generation solar cells, based in novel physical concepts, is also described. In summary, solar PV can be considered today as a mature technology for electricity production both at the large utility production plant level, or in domestic small-scale applications either isolated or grid connected.