Solar energy is a renewable energy source that is ultimately derived from the sun. It can be converted into electrical energy using solar panels, which are groups of solar cells that operate on the photoelectric effect to absorb light and generate electricity. When light strikes the solar cells, typically made of silicon, electrons are released and electrical current is generated. Large solar farms can be created using arrays of interconnected solar panels to produce usable amounts of direct current electricity on a commercial scale. While solar energy has advantages of being renewable and able to power remote areas, its generation and storage also have some disadvantages such as high costs and inefficient operation during cloudy conditions.

1. Solar energy
by
Siva shankar P G

2. 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

3. 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.

4. 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

6. 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

7. 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

8. the photovoltaic cell

9. 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

10.  “nellis solar power plant” contains 70,000 solar panels
that will generate 25 million kilowatt-hours

11.  “solar one”, california 1,800 sun-tracking mirrors reflect
heat to a central collector

12.  a solar farm in the philippines…

13.  pisay

14. 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

15. disadvantages
 solar panels are expensive
 solar power is inefficient in cloudy areas
 batteries and solar panels occupy more
space
 solar power maintenance is a problem
especially to those who doesn’t know the
proper technician
 disposal is difficult for the batteries and solar
panels when they have broken down
because they contain toxic chemicals like
lead, sulfuric acid & cadmium telluride

16. sources
 http://www.solarenergy-solarpower.com
 http://www.wikipedia.org [wikipedia]
 http://www.google.com [google
images]
 the world of science, vol 10, technology
of change