they would rock the world

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