history of photovoltiac cells (PV)
The photovoltiac effect was discovered a hundred years ago. Selenium photovoltiac cells were first introduced in the 1920's and present silicon devices in the 1950's. As early as in 1958 the USA and UDSSR used solar cells for the power systems of their satellites.
But the relatively high cost and low power output limited the use of photovoltiac cells to low power applications and situations where other sources are not available (spacecraft, etc.).
With the increased interest in their use following the oil crises of the 1970's long-lasting and highly reliable systems are now being developed at constantly reducing costs. New materials such as gallium arsenic may, however, prove cheaper and more efficient. For example, the earliest solar cells, developed by space scientists as a power source for satellites, were expensive to manufacture, costing more than US$ 2000,- per watt of output. Today's versions cost less than US$ 5,- per watt.
PV technology is now being used around the world for a wide range of applications, particularly where a relatively small amount of electricity is required in a remote situation, such as telecommunications equipment and remote village electrification.
next page: from sunshine to electrical current