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Sunlightsolar
energycan be used to generate electricity, provide hot
water, and to heat, cool, and light buildings.
Photovoltaic (solar cell) systems
convert sunlight directly into electricity. A solar or PV cell
consists of semiconducting material that absorbs the sunlight.
The solar energy knocks electrons loose from their atoms, allowing
the electrons to flow through the material to produce electricity.
PV cells are typically combined into modules that hold about
40 cells. About 10 of these modules are mounted in PV arrays.
PV arrays can be used to generate electricity for a single
building or, in large numbers, for a power plant. A power plant
can also use a concentrating solar power system, which uses
the sun's heat to generate electricity. The sunlight is collected
and focused with mirrors to create a high-intensity heat source.
This heat source produces steam or mechanical power to run
a generator that creates electricity.
Solar water heating systems
for buildings have two main parts: a solar collector and a
storage tank. Typically, a flat-plate collectora thin,
flat, rectangular box with a transparent coveris mounted
on the roof, facing the sun. The sun heats an absorber plate
in the collector, which, in turn, heats the fluid running through
tubes within the collector. To move the heated fluid between
the collector and the storage tank, a system either uses a
pump or gravity, as water has a tendency to naturally circulate
as it is heated. Systems that use fluids other than water in
the collector's tubes usually heat the water by passing it
through a coil of tubing in the tank.
There are a number of solar
incentives, both state and federal, to aid customers
in achieving their energy, economic, and environmental goals.
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