Photovoltaic or solar cells use the photovoltaic effect to convert photons in the form of sunlight into direct current electricity, used in combined arrays to power everyday objects such as calculators to communications on marine vessels and circuits on satellites.
First conceived of by Alexandre-Edmond Bacquerel in the 1830s and actually produced in the 1880's by Charles Fritts, they were only produced for practical applications to power satellites at the beginning of the current space age.
Solar cells utilize the properties of semi conductors, diodes and more recently quantum dots in the form of nanocrystals to produce electricity during the day which can be used or stored in batteries for use later on.
The primary advantages of solar cells over other forms of energy are their ability to be used in areas that traditional power station electricity cannot reach and their reputation as a key sustainable energy supply. Their initial development has been boosted by the space industry to advance the technology towards commercial terrestrial applications.