solar energy direct energy conversion

1. Solar energy technology
Submitted by
SAGAR M N
(1NT17MTP04)
THERMAL POWER ENGINEERING
Seminar on

2. • DIRECT ENERGY CONVERSION.
• SOLID-STATE PRINCIPLE.
• SEMICONDUCTORS.
• SOLAR CELLS PERFORMANCE.

3.  Transformation of one type of energy (such as sunlight) to another (such as
electricity) without passing through an intermediate stage (such as steam to
spin generator turbines).
 The fuel cell, another electrochemical producer of electricity, was
developed by William Robert Grove.
 Thermoelectric generators are devices that convert heat directly into
Electricity.
 In a solar cell, radiant energy drives electrons across a potential difference
at a semiconductor junction in which the concentrations of impurities are
different on the two sides of the junction.

4.  No conversion of energy into mechanical and to
electricity.
 Less losses in conversion process.
 More efficient process.
 Cost also reduced.

5.  Aim of Solid State
• Solid state physics (SSP) explains the properties of
solid materials as found on earth.
• Solid state physics is largely concerned with crystals
and electrons in the crystals.
• It gives details about how the large-scale properties of
solid materials results from their atomic -scale
properties.

6. Classification of solid state matter.
1. Gases.
2. Liquids.
3. Solids.
1. Gases
 Gases contain either atoms or molecules that do not
bond each other in a range of pressure, temperature and
volume.
 These molecules do not have any particular order and
move freely within a container.

7. 2.Liquids
• Similar to gases, liquids does not have any atomic
molecular order and takes the shape of the containers.
• Applying low levels of thermal energy can easily
break the existing weak bonds.

8. 3.Solids
• Solids consist of atoms or molecules which are
attached with one another with strong force.
• Solids (at a given temperature, pressure, and
volume) have stronger bonds between molecules
and atoms than liquids.
• Solids require more energy to break the bonds.
• Solids can take the form of crystalline, polycrstalline, or
amorphous materials

10. semiconductor materials which can perform useful
function in electronic apparatus & solid state research.
Ex: p-n junction diode,transistros, IC's and etc.

12.  There are two types of Semiconductors
1)Intrinsic Semiconductors
2)Extrinsic Semiconductors
Intrinsic Semiconductors: Tetravalent
Ex: Si, Ge etc
Extrinsic Semiconductors:
Ex: p-type and n-type

13.  Used in microcircuits.
 They're quite strong sturdy.
 Usually, they've long life.
 Switches turn on off with the use of transistor.

14.  What is a solar cell?
A structure that converts solar energy directly to DC
electric energy.
 It supplies a voltage and a current to a resistive load
(light, battery, motor).
• It is like a battery because it supplies DC power.
• It is different from a battery in the sense that the voltage
supplied by the cell changes with changes in the
resistance of the load.

15. • Si is covalently bonded: It shares electrons.
– When a Si atom is replaced with a group 3 (Al, B) it
forms a positive particle called a hole that can move
around the crystal through diffusion or drift (electric
field).
– When a Si atom is replaced with a group 5 (As, P) it
forms an electron that can move around the crystal.
– By selectively doping the Si Crystal when can change
the resistivity and which type of carrier transfers charge
(carries current). Because we can selectively dope a Si
crystal it is called a semiconductor.