The document discusses the history and development of solar power as an alternative renewable energy source. It describes how concerns over dependency on non-renewable energy in the 1970s led scientists to research new sources. Their work established solar power generated through concentrating solar and photovoltaic methods. The document then provides details on the technology behind solar cells and panels, and how they are able to convert sunlight into usable electricity through photovoltaic effects and semiconductor materials.

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.