solar energy
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Transcript of solar energy
WHAT IS SOLAR ENERGY?
Solar energy is the ultimate source of
energy from millions of years and it is
a renewable energy.
This energy consists of radiant light
and heat energy from the sun.
Out of all energy emitted by sun only a
small fraction of energy is absorbed
by the Earth.rgy
How is Solar energy is used?
We can use solar energy by converting
it to electrical energy . So we must use
a device called solar panels which can
convert the light energy into electrical
energy.
Solar panel is a group of solar cells.
Solar cells works on the principle of
photoelectric effect.
Photoelectric effect
When a light of certain
frequency falls on the
surface of a metal ,
electrons will absorb the
energy . If incident light
energy is greater than the
work function of the metal
,then the photo electrons
will be emitted and the
excess energy is converted
to the kinetic energy of
electron
photovoltaics
generating electrical power by converting
solar radiation into dc electricity using
semiconductors that exhibit the photovoltaic
effect
The photovoltaic effect is the creation
of voltage or electric current in a material
upon exposure to light
first observed by Alexandre-Edmond
Becquerel in 1839
the photovoltaic cell also called solar cell, is an electrical device that
converts the energy of light directly into electricity by
the photovoltaic effect
made of monocrystalline silicon or polycrystalline
silicon or amorphous silicon or cadmium telluride,
or copper indium selenide/sulfide
first built by Charles Fritts in1883 by coating
the semiconductor selenium with an extremely thin
layer of gold
the photovoltaic cell cont.
photons in sunlight hit the solar panel and are
absorbed by semiconducting materials, such
as silicon
electrons are knocked loose from their atoms,
and current starts flowing through the
material and this electricity is captured
an array of solar cells converts solar energy
into a usable amount of direct current [DC]
electricity
“nellis solar power plant” contains 70,000 solar panels
that will generate 25 million kilowatt-hours
advantages
solar energy is a renewable source of energy
in the presence of solar power, use of non-
renewable sources of energy like petroleum
can be lessened which also lessens pollution
unlike others, solar energy can be harnessed
and used in remote locations like mountains
even though solar panels are expensive, the
total amount that would be saved makes the
price of the panels will seem small
disadvantages solar panels are expensive
solar power is inefficient in cloudy areas
batteries and solar panels occupy morespace
solar power maintenance is a problemespecially to those who doesn’t know theproper technician
disposal is difficult for the batteries and solarpanels when they have broken downbecause they contain toxic chemicals likelead, sulfuric acid & cadmium telluride