UNIT-2
Contents as per syllabus:
1. Solar Radiation
1.1. Energy & Radiation
1.2. Solar Structure
1.3. Sun – Earth Relationships
1.4. Solar Irradiance
1.5. Basic Solar Components
2. Solar Collectors
2.1. Introduction
2.2. Classification of Solar Collectors
2.3. Applications
3. Flat Plate Collectors
3.1. Introduction
3.2. Materials
3.3. Construction & Working
3.4. Applications & Performance
4. Evacuated Tube Collectors
4.1. Introduction
4.2. Materials
4.3. Construction & Working
4.4. Applications & Performance
5. Solar Concentrating Collectors
5.1. Introduction
5.2. Materials
5.3. Construction & Working
, 5.4. Applications & Performance
6. Solar Thermal Power Plant
6.1. Introduction
6.2. Schematic Diagram of various solar thermal plants
7. Short Answer Questions
8. University asked Questions
9. MCQs
,1. Solar Radiation
1.1. Energy & Radiation
Radiation: The transfer of energy via electromagnetic waves that travel at the speed of light.
The velocity of light in a vacuum is approximately 3 x 108 m/s.
The time it takes light from the sun to reach the Earth is 8 minutes and 20 seconds.
Heat transfer by electromagnetic radiation can travel through empty space.
Anybody above the temperature of absolute zero (-273.15o C) radiate energy to their
surrounding environment.
The many different types of radiation is defined by its wavelength. The electromagnetic
radiation can vary widely.
Figure 1.Wavength Chart
Figure 2.Solar Radiation
, Solar radiation, often called the solar resource or just sunlight, is a general term for the
electromagnetic radiation emitted by the sun.
Solar radiation can be captured and turned into useful forms of energy, such as heat and
electricity, using a variety of technologies.
However, the technical feasibility and economical operation of these technologies at a specific
location depends on the available solar resource.
1.1.1 Basic Principles
Every location on Earth receives sunlight at least part of the year. The amount of solar radiation
that reaches any one spot on the Earth's surface varies according to:
Geographic location
Time of day
Season
Local landscape
Local weather.
Because the Earth is round, the sun strikes the surface at different angles, ranging from 0° (just
above the horizon) to 90° (directly overhead).
When the sun's rays are vertical, the Earth's surface gets all the energy possible.
The more slanted the sun's rays are, the longer they travel through the atmosphere, becoming
more scattered and diffuse.
Because the Earth is round, the frigid polar regions never get a high sun, and because of the
tilted axis of rotation, these areas receive no sun at all during part of the year.
The Earth revolves around the sun in an elliptical orbit and is closer to the sun during part of
the year.
When the sun is nearer the Earth, the Earth's surface receives a little more solar energy.
The Earth is nearer the sun when it is summer in the southern hemisphere and winter in the
northern hemisphere.
However, the presence of vast oceans moderates the hotter summers and colder winters one
would expect to see in the southern hemisphere as a result of this difference.
The 23.5° tilt in the Earth's axis of rotation is a more significant factor in determining the
amount of sunlight striking the Earth at a particular location. Tilting results in longer days in
the northern hemisphere from the spring (vernal) equinox to the fall (autumnal) equinox and
longer days in the southern hemisphere during the other 6 months. Days and nights are both
Contents as per syllabus:
1. Solar Radiation
1.1. Energy & Radiation
1.2. Solar Structure
1.3. Sun – Earth Relationships
1.4. Solar Irradiance
1.5. Basic Solar Components
2. Solar Collectors
2.1. Introduction
2.2. Classification of Solar Collectors
2.3. Applications
3. Flat Plate Collectors
3.1. Introduction
3.2. Materials
3.3. Construction & Working
3.4. Applications & Performance
4. Evacuated Tube Collectors
4.1. Introduction
4.2. Materials
4.3. Construction & Working
4.4. Applications & Performance
5. Solar Concentrating Collectors
5.1. Introduction
5.2. Materials
5.3. Construction & Working
, 5.4. Applications & Performance
6. Solar Thermal Power Plant
6.1. Introduction
6.2. Schematic Diagram of various solar thermal plants
7. Short Answer Questions
8. University asked Questions
9. MCQs
,1. Solar Radiation
1.1. Energy & Radiation
Radiation: The transfer of energy via electromagnetic waves that travel at the speed of light.
The velocity of light in a vacuum is approximately 3 x 108 m/s.
The time it takes light from the sun to reach the Earth is 8 minutes and 20 seconds.
Heat transfer by electromagnetic radiation can travel through empty space.
Anybody above the temperature of absolute zero (-273.15o C) radiate energy to their
surrounding environment.
The many different types of radiation is defined by its wavelength. The electromagnetic
radiation can vary widely.
Figure 1.Wavength Chart
Figure 2.Solar Radiation
, Solar radiation, often called the solar resource or just sunlight, is a general term for the
electromagnetic radiation emitted by the sun.
Solar radiation can be captured and turned into useful forms of energy, such as heat and
electricity, using a variety of technologies.
However, the technical feasibility and economical operation of these technologies at a specific
location depends on the available solar resource.
1.1.1 Basic Principles
Every location on Earth receives sunlight at least part of the year. The amount of solar radiation
that reaches any one spot on the Earth's surface varies according to:
Geographic location
Time of day
Season
Local landscape
Local weather.
Because the Earth is round, the sun strikes the surface at different angles, ranging from 0° (just
above the horizon) to 90° (directly overhead).
When the sun's rays are vertical, the Earth's surface gets all the energy possible.
The more slanted the sun's rays are, the longer they travel through the atmosphere, becoming
more scattered and diffuse.
Because the Earth is round, the frigid polar regions never get a high sun, and because of the
tilted axis of rotation, these areas receive no sun at all during part of the year.
The Earth revolves around the sun in an elliptical orbit and is closer to the sun during part of
the year.
When the sun is nearer the Earth, the Earth's surface receives a little more solar energy.
The Earth is nearer the sun when it is summer in the southern hemisphere and winter in the
northern hemisphere.
However, the presence of vast oceans moderates the hotter summers and colder winters one
would expect to see in the southern hemisphere as a result of this difference.
The 23.5° tilt in the Earth's axis of rotation is a more significant factor in determining the
amount of sunlight striking the Earth at a particular location. Tilting results in longer days in
the northern hemisphere from the spring (vernal) equinox to the fall (autumnal) equinox and
longer days in the southern hemisphere during the other 6 months. Days and nights are both
