Currently, solar power
technologies use photovoltaic (PV) panels to convert
sunlight directly into electricity. This process
involves no moving parts. PV systems can be very
small (using only a few panels) or several panels
can be coupled together to produce large systems.
The panels constructed of semiconducting materials
similar to those used in making computer chips. When
sunlight is absorbed by these materials, the solar
energy knocks electrons loose from their atoms,
allowing the electrons to stream through the
material to create electricity. This process of
converting light (photons) to electricity (voltage)
is known as the photovoltaic (PV) effect.
 Solar
cells are usually combined into modules that hold
about 40 cells; about 10 of these modules are
mounted in PV arrays that can measure up to several
feet on a side. These flat-plate PV arrays can be
mounted at a fixed angle facing south, or they can
be mounted on a tracking device that follows the
sun, allowing them to capture the most sunlight
throughout the day. About 10 to 20 PV arrays can
provide enough power for a single household.
Because the electricity produced by PV arrays is in
the form of direct current, if the electricity is
supplied to the electric power grid, the arrays need
to be coupled to an inverter which converts the
direct current (DC) into alternating current (AC).
Once converted to the appropriate voltage and
frequency, the electricity can be directed to the
electric grid.
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