Photovoltaics Solar Power

Photovoltaic (PV) solar devices convert directly light into electricity, through the photovoltaic effect. The process works even on cloudy or rainy days, though with reduced energy production and conversion efficiency. PV cells are assembled into modules which are the basic elements of PV systems. Current commercial PV technologies include wafer-based crystalline silicon (c-Si) (either mono-crystalline or multi-crystalline silicon) and thin-films (TF) using amorphous Si (a-Si/c-Si), cadmium-telluride (CdTe) and copper-indium-[gallium]-[di]selenide-[di]sulphide (CI[G]S). The production volume of thin-films has been decreasing during the past years due to lower efficiency and cost competitiveness. In 2014 the c-Si systems accounted for 92% of the market. Novel PV concepts such as concentrating PV and organic PV are under development. Over the past decades PV technology has been constantly improving performance and reducing costs. As a result, PV power is expanding rapidly in many countries. The global cumulative PV capacity (only 1.4 GW in 2000) has reached the level of about 225 GW at the end of 2015, with about 50 GW of new capacity in the last year. China now leads the cumulative capacities with 43.6 GW, followed by Germany with 39.7 GW, Japan (34,4 GW), USA (25.6 GW) and Italy (18.9 GW). All other countries are far behind in terms of cumulative PV installations and below the 10 GW mark.