Converting light directly into electricity by the photovoltaic effect was first observed by the French physicist Edmond Becquerel in 1839.
When photons shining in REC photovoltaic system, generally made of silicone, they emit electrons from their stable position, allowing them to move freely through the material.
A voltage can then be produced using semiconductor junction. A method for producing highly pure crystals of silicon for photovoltaic cells with high voltage and efficiency are developed in the 1940s. It proved to be a tremendous boost to the industry.
There are two approaches to reduce high price: cheap produce materials for so-called flat plate systems, and using lenses or reflectors to concentrate sunlight into a smaller area of the (expensive) solar cells.
Concentrating systems must track the sun and does not use diffuse light caused by clouds most efficient flat plate systems. They do, however, capture more light early and late in the day.
Almost all current operating photovoltaic device is a flat plate systems. Some rotate to track the sun, but most do not have any moving parts. One may be optimistic about the future of these devices are commercially available for efficiencies far below the theoretical limit and therefore only the modern manufacturing techniques are now being applied.