Flat plate collectors are the most common type of solar collector and consist of an absorber plate, transparent cover, heat transport fluid, and insulation. Integral collector storage employs oversized piping or channels within the collector to increase thermal storage capacity without an external tank. Evacuated tube collectors use heat pipes or direct flow of liquid through glass tubes to transfer heat to a fluid in an insulated manifold. Solar air collectors directly heat air for applications like space heating using glazed or unglazed absorber plates.

2. Integral Collector Storage

3. ntegral collector storage (ICS)
Integral collector storage is a method of
storing thermal energy within the
collector itself. Although a standard
thermal collector has some storage
capacity in its piping, ICS employs either
oversize piping or large formed
rectangular box channels, to increase
the stored liquid capacity within the
collector. This allows for additional
thermal capacity without requiring a
separate insulated storage tank

4. Flat Plate Collectors

5. Flat plate
collectorsFlat-plate collectors, developed by Hottel
and Whillier in the 1950s, are the most
common type. They consist of (1) a dark
flat-plate absorber of solar energy, (2) a
transparent cover that allows solar energy
to pass through but reduces heat losses,
(3) a heat-transport fluid (air, antifreeze
or water) to remove heat from the
absorber, and (4) a heat insulating
backing.

6. Evacuated tube collectors

7. Evacuated tube collectors
Most vacuum tube collectors in use in middle Europe
use heat pipes for their core instead of passing liquid
directly through them. Direct flow is more popular in
China. Evacuated heat pipe tubes (EHPTs) are
composed of multiple evacuated glass tubes each
containing an absorber plate fused to a heat pipe. The
heat from the hot end of the heat pipes is transferred
to the transfer fluid (water or an antifreeze mix—
typically propylene glycol) of a domestic hot water
or hydronic space heating system in a heat exchanger
called a "manifold". The manifold is wrapped in
insulation and covered by a sheet metal or plastic case
to protect it from the elements.

8. Solar Air Heat Collector

9. Solar air heat collectors
heat air directly, almost always for space heating. They
are also used for pre-heating make-up air in
commercial and industrial HVACs stems. They fall into
two categories: Glazed and Unglazed.
Glazed systems have a transparent top sheet as well as
insulated side and back panels to minimize heat loss to
ambient air. The absorber plates in modern panels can
have an absorptivity of more than 93%. Air typically
passes along the front or back of the absorber plate
while scrubbing heat directly from it. Heated air can
then be distributed directly for applications such as
space heating and drying or may be stored for later
use.

10. Solar Bowl

11. Solar bowl
is a type of solar thermal collector that operates
similarly to a parabolic dish, but instead of using
a tracking parabolic mirror with a fixed receiver,
it has a fixed spherical mirror with a tracking
receiver. This reduces its efficiency but makes it
cheaper to build and operate. Designers call it
a fixed mirror distributed focus solar power
system. The main reason for its development was
to eliminate the cost of moving a large mirror to
track the sun as with parabolic dish systems

12. Types of Solar
Collectors for
Electricity Generation

13. Parabolic Trough

14. This type of collector is generally
used in solar power plants. A trough-
shaped parabolic reflector is used to
concentrate sunlight on an insulated
tube (Dewar tube) or heat pipe,
placed at the focal point,
containing coolant which transfers
heat from the collectors to
the boilers in the power station.
Parabolic trough

15. Parabolic Dish

16. Parabolic dish
With a parabolic dish collector, one or
more parabolic dishes concentrate
solar energy at a single focal point, —
similar to the way a reflecting
telescope focuses starlight, or a dish
antenna focuses radio waves. This
geometry may be used in solar
furnaces and solar power plants

17. Solar Tower

18. Concentrated solar power (also
called concentrating solar
power, concentrated solar thermal, and CSP)-systems use mirrors or lenses to concentrate a
large area of sunlight, or solar thermal energy,
onto a small area. Electrical power is produced
when the concentrated light is converted to
heat, which drives a heat engine (usually
a steam turbine) connected to an electrical
power generator or powers an, experimental as
of 2013, thermochemical reaction
- is surrounded by tracking mirrors
called heliostats. These mirrors align
themselves and focus sunlight on the receiver
at the top of tower, collected heat is
transferred to a power station below.

19. Advantages of Solar Tower
-Very high temperatures reached. High temperatures are suitable
for electricity generation using conventional methods like steam
turbine or a direct high temperature chemical reaction such as liquid
salt.
-Good efficiency. By concentrating sunlight current systems can get
better efficiency than simple solar cells.
-A larger area can be covered by using relatively inexpensive mirrors
rather than using expensive solar cells.
-Concentrated light can be redirected to a suitable location
via optical fiber cable for such uses as illuminating buildings.
-Heat storage for power production during cloudy and overnight
conditions can be accomplished, often by underground tank storage
of heated fluids. Molten salts have been used to good effect.

20. Disadvantages of Solar Tower
-Concentrating systems require sun tracking to
maintain Sunlight focus at the collector.
-Inability to provide power in diffused
light conditions. Solar Cells are able to provide
some output even if the sky becomes a little bit
cloudy, but power output from concentrating
systems drop drastically in cloudy conditions as
diffused light cannot be concentrated passively.

22. Dark
Energy

23. Why is the universe speeding up?
In 1998, two teams of astronomers studying distant supernovae made
the remarkable discovery that the expansion of the universe is speeding
up. Yet, according to Einstein's theory of General Relativity, gravity
should lead to a slowing of the expansion. To explain cosmic
acceleration, cosmologists are faced with two possibilities: Either 75%
of the universe exists in an exotic form, now called dark energy, that
exhibits a gravitational force opposite to the attractive gravity of
ordinary matter, or General Relativity must be replaced by a new theory
of gravity on cosmic scales.
The Dark Energy Survey (DES) is designed to probe the origin of the
accelerating universe and help uncover the nature of dark energy by
measuring the 14-billion-year history of cosmic expansion with high
precision. More than 120 scientists from 23 institutions in the United
States, Spain, the United Kingdom, Brazil, and Germany are working on
the project. This collaboration is building an extremely sensitive 570-
Megapixel digital camera, DECam, and will mount it on the Blanco 4-
meter telescope at Cerro Tololo Inter-American Observatory high in
the Chilean Andes. Starting in Sept. 2012 and continuing for five years,
DES will survey a large swath of the southern sky out to vast distances
in order to provide new clues to this most fundamental of questions.

25. Albert Einstein,
1947. Einstein used
his "cosmological
constant" to help
describe a static
universe. When he
learned the universe
was expanding, he
discarded it.

26. Einstein
theorized that
mass warps
the shape of
space,
creating the
force we call
gravity.
Einstein
theorized that
mass warps
the shape of
space,
creating the
force we call
gravity.

32. Supernova 1994D in NGC4526

35. The Corpuscular TheoryThe Corpuscular TheoryThe Corpuscular TheoryThe Corpuscular TheoryThe Corpuscular Theory
The Corpuscular Theory
--- Created in the seventeenth century by Sir
Isaac Newton
--- States that light emitted by luminous objects
consist of tiny particles of matter
called corpuscles. When corpuscles hit a surface,
each partice is reflected.
--- Thought that light traveling from air into water
will increase the speed, while light entering
water will decrease the speed.

36. The Wave Theory
--- Discovered by Christian Huygens, a Dutch scientist, also in the
seventeenth century
--- States that light is emitted in a series of waves that spread out
from a light source in all directions. These waves are not affected
by gravity.
--- Furthermore, he disagreed with Newton and said that light
traveling from air to water will decrease the speed, and vice versa.
Huygens was proved later to be correct.
--- 100 years later, Englishman Thomas Young completely
disproved the corpuscular theory by showing that light waves can
interfere with each other.

37. The Electromagnetic Theory
--- Discovered in the nineteenth century
by James Maxwell
--- Proposed that light waves do not require
a medium for transmission.
--- Light waves posses electrical and
magnetic properties and can travel though a
vacuum. Light waves are a part of a larger
family of electromagnetic waves and make
up the electromagnetic spectrum.

38. THE QUANTUM THEORY
---discovered by Max Planck, a German scientist in 1990
--- Stated that light waves travel as
separate packets of energy
called quanta or photons. --- Merged the
subjects of the Corpuscular, Wave, and
Electromagnetic Theories together.
Later, it was proved that the correct and
most accurate theory was the Quantum
Theory.

39. Speed of Light
The speed of light is much greater than the speed of sound.
Olaus Roemer --- Danish Scientist, 1st method to find the speed of
light, used the planets, he calculated the speed of light was 227,000
kilometers per second
Albert A. Michelson --- 1926, developed a more modern method to
determine the speed of light, used mirrors, calculated the speed of light to be
186,285 miles per second (299,796 kilometers per second)
The wavelength of any electromagnetic vibration x its frequency = the speed
of the electromagnetic vibration
Scientists have determined that the speed of any electromagnetic vibration =
the speed of light (approximate value of the speed of light is 300,000
kilometers per second)
The speed of an electromagnetic wave is not affected by temperature, but it
is affected by the medium through which it travels.

40. Transmission of Light
Light can travel through a vacuum.
Opaque Objects --- completely block light
and through which you cannot see
Transparent Objects --- readily transmit
light and through which you can see clearly
Translucent Objects --- allow light to pass
through partially or that distort the light so that
you cannot see through them

41. Behavior of Light
Light travels in a straight line.
Pinhole Camera --- the object that is viewed is
upside-down
Shadow --- the dark space behind an object that is
formed when light is blocked by that opaque object
Umbra --- the darker central portion of the shadow
that receives no light from the source
Penumbra --- the lighter shadow that surrounds the
umbra and receives some light from outer edges of the
light source