FROM RENEWABLE ENERGY SOURCES FORM EXCEL POLYTECHNIC

1. Excel polytechnic college
DEPARTMENT OF MECHANICAL
ENGINEERING

2. SEMINAR
RENEWABLE ENERGY SOURCES AND
ENERGY CONSERVATION

3. TITLE : SOLAR ENERGY AND PV CELLS
SUBJECT : THERMAL & AUTOMOBILE
SECTION : C
DEPARTMENT : Mechanical Engineering
Submitted by
NITHIN VSTAFF SIGNATURE

4. Contents :
Basic Concept of Solar energy
Physics of Photovoltaic cells
PV modules
Emerging Technologies
Environmental Aspects
Indian Scenario
Application of solar panel
Disadvantages of solar cells

5. History of Solar Cells :
Discovery of Photovoltaic effect by French physicist , Alexandre-
Edmond Becquerel.
A description of the first solar cells made from selenium wafer were
made by Charles Fritts and operated at 1% effeciency .
Charles Fritts constructed what was probably the first true solar cell.
He coated a semiconductor material (selenium) with an extremely thin
layer of gold.
A cadmium sulphide p-n junction was produced with an efficiency of
6%
Audobert and Stora discover the photovoltaic effect in cadmium
sulfide (CdS).
The The Fraunhofer Institute for Solar Energy achieve a 44.7% efficiency
solar cell technology.
The University of South Wales breaks the 20% efficiency barrier for
silicon solar cells under one sun conditions.

6. What is solar energy?
radiant energy emitted by the
sun.
The Sun daily provides about 10,000 times more energy to the Earth
than we consume.
The earth receives 174 petawatts [1015 watts] of solar radiations
from the sun.
The total energy absorbed by earth’s atmosphere, oceans, land mass is
3,850,000 exajoules [1018 joules] per year.
The energy reaching earth’s atmosphere consists of about 8% UV
radiation, 46% visible light, 46% infrared radiations.

7. Why Solar Energy ?
Solar energy is the most readily available source of energy.
It is free.
It is also the most important of the non-conventional sources of energy
because it is non-polluting.
It is a renewable source of energy.
(Renewable Energy) (Nonrenewable Energy)

8. What is a Photovoltaic Cell?
also called solar cell, is an electrical device that converts the energy
of light directly into electricity by the photovoltaic effect.
Solar Cell (PV)
Light Electricity

9. When sun light falls on silicon metal
cell, the photon energy allows the
electrons from the P-layer to move to
the N-layer, creating an electric
potential difference on the
semiconductor borders.
If these borders are connected to a
load by conductive wires, there will
be a flow of electric current, getting
back the electrons to the P-layer and
starting the process again.
A photovoltaic cell generally has low
current and voltage levels, of about 3
A and 0.7 V, respectively.
Operation of a solar cells :

11. Types of PV cells:
Silicon Crystalline
Cells
Thin Film Cells
made by using crystalline silicon
solar cells , developed from the
microelectronics technology
industry.
made by depositing one or more
thin layers (thin film) of
photovoltaic material on a
substrate.
Mono Crystalline PV Cells
Multi Crystalline PV Cells
Amorphous Silicon PV
Cells
Poly Crystalline PV
Cells
(Non-Silicon based)

12. Amorphous Silicon PV Cells :
 The most advanced of thin film technologies .
 Operating efficiency ~6% .
 Makes up about 13% of PV market .
PROS
• Mature manufacturing
technologies available .
CONS
• Initial 20-40% loss in efficiency
.

13.  Solar panels are expensive.
 Solar power is inefficient in cloudy areas.
 A solar energy installation requires a large area for the system to be
efficient in providing a source of electricity.
 Solar power maintenance is a problem especially to those who
doesn’t know the proper techniques.
 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.
Disadvantages of solar cells :
Solarbuzz European and US All Solar
Module
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