Transcript Solar Energy - 02kroskyCeng12

Solar Energy
Solar panels
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Instead of using fossil fuels, 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 many panels can be connected together to construct
large systems.
More info
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The panels are made of semiconducting materials similar to those used in computer
chips. When sunlight is absorbed by these materials, the solar energy knocks
electrons loose from their atoms, allowing the electrons to flow through the material
to produce electricity. This process of converting light (photons) to electricity
(voltage) is called the photovoltaic (PV) effect.
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Solar cells are typically combined into modules that hold about 40 cells; about 10
of these modules are mounted in PV arrays that can measure up to several meters
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 over the course of a day. About 10 to 20 PV arrays can
provide enough power for a 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 changes the direct current into alternating current. Once converted to
the appropriate voltage and frequency, the electricity can be supplied to the electric
grid.
How much it costs
• As a very rough guide, depending on the above conditions - - • A solar hot water system will cost between US $2,000 and $4,000.
A photovoltaic system will cost between US $8,000 and $10,000 for a 1kW system. (or
$8 - $10 /Watt) An average American family, living in a 3-bedroom home will
require a 1.5 - 3kW system, which will cost between US $13,000 and US $27,000,
before rebates.
This will help save up to 40% of engery bill if u have solar engery it very good for
home owners.