"Photovoltaic technology has now reached an installed base of 300 GWp globally (end 2016), providing 1 to 2% of the global electricity demand, and up to 100% during the summer in some regions. In every scenario towards addressing the climate problem, photovoltaic technology has a prominent role. It is a proven technology, it generates electricity at costs competitive to fossil fuels in many regions of the world, it has a very low carbon footprint, it is modular, it can be installed on roofs to provide electricity directly to the inhabitants of the house, and field installations already entering the GW level. It is expected that the global installed capacity will exceed the terawatt level in the next five years. The cost of manufacturing of PV modules is decreasing at a significant rate, around 12% per year while the average efficiency of commercial PV modules is increasing by 2% relative per year (or about 0.5% absolute). In the labs, the best efficiency ever reported for any PV device is approaching 50%. Several PV technologies for single junction PV devices are approaching the maximum theoretical limit, and the industry is seriously considering the use of tandem junction technologies as the next technology node for commercial terrestrial applications"--