2. The energy crisis and oil embargos of the 1970’s made
many nations aware of their dependency on controlled
non-renewable energy sources .
This formulated the scientists to search for new
alternative sources of energy.
Further researches into renewable sources made a
path through solar power, wind power and geothermal
power.
Solar power generation has emerged as one of the
most rapidly growing renewable sources of energy.

3.  Solar power is the conversion of
sunlight into electricity .
 The methods used for generating
electricity through solar power are:
1. Concentrated solar power(CSP)
2. Photovoltaic method .

4.  CSP systems use mirrors or lenses to
concentrate a large area of sunlight on to a
small area.
 Electrical power - produced when
concentrated light is converted to heat-
drives heat engine connected to electric
power generator.

5.  The French physicist -Edmond
Becquerel - demonstrated photo
voltaic activity.
 Photovoltaics – a method of
generating electrical power –
converts solar radiation into
direct current electricity.
 This is done by using
semiconductors

6.  The first solar
cell was
constructed by
Charles Fritts.
 Solar cells are
devices converts
“photons” of light
energy directly
into electricity.
 They function by
photovoltaic
effect.

7.  Transparent
Adhesive
 Encapsulate
 Anti-reflective
Coating
 N-Type Silicon
 P-Type Silicon
 Back Contact

8.  Silicon – Phosphorus system
form a part of solar cell.
 Free electrons and holes are
generated on both the sides of
the junction.
 Current is produced due to these holes
and electrons.

9.  Photon strikes the
solar cell-is absorbed
if its energy is
greater than band
gap value energy.
 Electron receives
energy and excites
into Conduction band
from Valence band.
 Electric field created
in PV cell provides
the required voltage
to drive electrons to
external circuit

10.  Electrons from n-type and holes from p-
type flow towards p and n type materials
respectively, when they are sandwiched
together inside a PV cell.
 An electric field at the junction is formed.
 It repels electrons – causes electrons to
jump towards surface.
 Thus electrons are available for electric
circuit.
 With the help of electric field that
provides voltage electrons are driven into
the electric circuit.
 Thus electrical current is produced.

12.  A solar panel -
assembly of
photovoltaic cells.
 A solar panel -
collects and utilizes
heat energy from the
sun.
 Multiple cells in
integrated group, all
oriented in one plane
form a “solar thermal
module” .

13.  When photons strike
the solar panels they
convert into electrons
of direct current (DC).
 These electrons flow
out of the panel and
into an inverter.
 The inverters converts
the DC power into AC
power.

14.  Solar array -a
linked collection of
solar panels.
 PV arrays use -
inverter and
convert DC power
produced by the
module into AC.
 It is used to power
the house hold
appliances and
other loads.

15. PV can be used in variety of
applications:
 Consumer products
 Emergency power systems
 Vaccine and blood storage
refrigerators
 Aeration system for ponds
 Power supply for satellites and space
vehicles

17.  It is in Charanka
village in Gujarat.
 It is the Asia‟s
first and largest
power park.
 It contributes
about 2/3rd „s of
the 900MW of the
total power
generated in the
country.

19.  Avoids green-house gases
 Infinite free energy
 Decentralisation of power
 Saving eco-systems and livelihood
 Their life span is more
 Easy installation

20. It is extremely “expensive”
Solar power is inefficient
Solar panels are bulky
Need for a large amount of
area.