Introduction to solar thermal system Working of solar thermal system Solar collector Type of solar collector Solar water heater Solar heating and cooling Solar refrigeration and air conditioning Advantage and Disadvantages

1. Solar
thermal
system
THE INSTISTUTE OF SCIENCE
COURSE CODE;-MPHSEC2T
S U N I L D H A N A R E
MI L I N D P U N J A R A
D H I R A J K U MA R G U P TA
SUNITA SHAH

2. TOPICS
•Introduction to solar thermal system
•Working of solar thermal system
•Solar collector
•Type of solar collector
•Solar water heater
•Solar heating and cooling
•Solar refrigeration and air conditioning
•Solar-cookers,dryers,distillation
•Advantage and Disadvantages

3. Introduction:
Sun is the most abundant,reliable and renewable source of energy.
This energy can be harnessed by two way:
1).Solar thermal 2).Solar photovoltaic
Solar thermal energy is the advance techniques which produces maximum efficient
enrgy compare to photovoltaic cell.

4. Year Description
1866 Auguste Mouchout used a parabolic trough to produce steam for the first solar steam
engine
1886 First patent for a solar collector was obtained by the Italian Alessandro Battaglia in
Genoa, Italy
1913 Frank Shuman finished a 55 HP parabolic solar thermal energy station in Maadi, Egypt
for irrigation
1929 First solar-power system using a mirror dish was built by American Scientist Dr. R.H.
Goddard.
1968 First concentrated-solar plant, which entered into operation in Sant'Ilario, near Genoa,
Italy
1984 Parabolic-trough technology of the Solar Energy Generating Systems (SEGS) begun its
combined capacity354 MW.
2014 World's largest solar thermal plant (392 MW) achieves commercial operation in Ivanpah
Califoma, USA
History

5. Solar thermal system:
•Solar thermal power (electricity) generation systems
collect and concentrate sunlight to produce the high
temperature heat needed to generate electricity.
•Solar thermal collectors can absorb nearly the entire
solar spectrum.
•Thus concentrated solar power (CSP) technology is
more efficient than photovoltaic solar cells.

6. Solar collector:
• Solar power has low density per unit area (1
kW/sq. m. to 0.1 kW/sq. m.) hence it is to be
collected by covering large ground area.
• Solar thermal collector essentially forms the first
unit in a solar thermal system.
• It absorbs solar energy as heat and then
transfers it to heat transport fluid efficiently.
• The heat transport fluid delivers this heat to
thermal storage tank / boiler / heat exchanger,
etc., to be utilized in the subsequent stages of
the system.

7. Concentrating solar
technologies
Low temperature (<100 C)
Medium temperature-line
focusing(<400 C)
High temperature –point
focusing(>400 C)
1. flat plate collector
2. solar chimney
3. solar pond
1. Parabolic trough
collector(PTC)
2. Fresnel collector
1. Central tower collector
2. Parabolic dish collector
Classification of solar collector on basis of their concentrating temperature

8. 1.Low temperature collectors (<100 "C):
Flat plate solar collector
Flat plate collector is basically a black surface
that is placed at a convenient path of a sun
The sun heats a dark flat surface, and then the
energy is transferred to water, air, or other fluid
for further use•
These are used in domestic house hold purpose
like water heating & space heating etc.They
operate in the temperature range from 30 to 80
"C.

9. 2. Medium temperature collectors –
Line focusing (<400 °C):
Parabolic trough collector (PTC):
•Parabolic trough is the linear-focus collector.
•It consists of a cylindrically curved parabolic mirror,
which reflects the sunlight onto a tubular receiver
positioned in the focus line of the parabola..
•The tubular receiver contains the fluid that absorbs
heat and transfers it via circulation to the boiler or
another device to produce steam.
•PTCS are made by simple bending a sheet of
reflective or highly polished material into a parabolic
shape.

10. 3. High temperature collectors –
Point focusing (>400 "C):
Central tower collector:
• In this system multiple tracking mirrors (heliostats)
positioned in the field around central receiver installed on
a tower
•These systems are capable of reaching of much higher
levels of concentration than linear systems
•Typically 80 to 95% of the reflected energy is absorbed
into the working fluid which is pumped up into the receiver
•The working fluid is used as heat source to produce
steam and convert it to electricity•
• The generated thermal energy can be stored in amolten
salt storage

11. Solar water heater
A Solar Water Heater is a device which provides
hot water for bathing, washing, cleaning, etc. using
solar energy.
It is generally installed at the terrace or where
suntight is availableA tilted flat plate solar collector
with water as heat transfer fluid is used.

12. Working of solar water heater
• A thermally insulated hot water storage tank is mounted above the collector.
•The heated water of the collector rises up to the hot water tank and replaces an equal
quantity of cold water, which enters the collector.
• The cycle repeats, resulting in all the water of the hot water tank getting heated up.
•When hot water is taken out from hot water outlet, the same is replaced by cold water from
cold-water make up tank fixed above the hot water tank. The scheme is known as passive
heating scheme,
•When the collector is fixed above the level of hot water tank, a pump is required to induce
circulation of water in the loop and the scheme will be known as active (or forced) solar
thermal system

13. Solar heating and cooling technology:
solar heating
•Solar heating and cooling technology receive the
thermal energy from sun and utilize this energy to
provide hot water, space heating and pool heating for
residential, commercial and industrial applications.
• These applications of SHCS reduce the dependency
on electricity or natural fuels.
• The main function of solar system is to convert sun
light into heat.
•The primary requirement of SHCS is to setup the light
collectors with higher efficiency

14. Active and passive Solar heating:
ACTIVE SOLAR HEATING:
• This system can be used as commercial hot
water as well as space heat.
• A space heat application involves some
additional connecting hardware for space
heat distribution system.
• Active solar heating system involve
following major components:Collectors to
absorb energy,Circulation system,Storage
tank,Backup heating system, Control system
PASSIVE SOLAR HEATING:
•Passive solar heating is the least costly
technique to heat home space.
• The main aim of this system is to kept out
heat in summer and kept in heat in winter from
sun light.
•Passive solar heating also depends on
ventilation or windows provided in buildings
or houses.

15. Solar cooling
Solar cooling is a technology that converts sun light heat energy into useful
cooling of buildings. The process works by using solar heat collecting and
supplied this heat to the thermal cooling system, to generate chilled water.

16. Solar air conditioning and refrigeration:
Solar refrigeration
•The principle of absorption refrigeration was
first demonstrated by Faraday in 1825. Thus,
this is one of the oldest cycles for producing
refrigeration effect, which differs fundamentally
from the conventional vapour compression
cycle in the method for compressing the
refrigerant.
•Refrigerator which run on electricity provided
by solar energy is known as solar refrigeration

17. Working of solar refrigerator
•In absorption cycle cooling systems two working fluids: a refrigerant and an absorbent-refrigerant solution are used.
•The absorbent-refrigeration combination is so chosen that the absorbent have high affinity for the refrigerant and at the same
temperature, vapour pressure of the refrigerant is higher than that of absorbent.
•The absorbent cooling is based on the principle that the refrigerant can be bound by a liquid or solid solvent, known as
absorbent to release heat during absorption, while it absorbs heat during evaporation (and thus producing cooling effect).
•Though large number of refrigerant-absorbent combination is possible, the two most common and commercially tried
combinations are: LiBr-water (LiBr as absorbent and water as 176 Non-Conventional Energy Resources refrigerant) and
aqua-ammonia (water as absorbent and ammonia as refrigerant).
•In the former the absorbent is a solid (a salt) whereas in the later it is a liquid.
•The performance of a cooling cycle is judged from its COP (coefficient of performance), which is defined as the ratio of
amount of cooling produced to the energy input.

18. Solar air conditioning and refrigeration:
Solar air conditioning:
•Air-conditioning is one of the majorconsumers of electrical
energy.
•The demand can be expected to increase because of changing
working times, increased comfort expectations and global
warming.
•Solar air-conditioning might be a way to reduce the demand
for electricity.
•Process of converting solar thermal energy (heat) into
conditioned

19. Conventional vs solar air conditioning
CONVENTIONAL AIR CONDITIONING
•When a liquid gas changes its state, it
takes or extract heat.
•At lower pressure, state changes at lower
temp.
•Extraction of heat means cooling.
•Gas gets compressed when heated.
•Gaseous refrigerant compressed and then
heated up in the solar panel up to 90°C.
SOLAR AIR CONDITIONING
•In this system, water is used as the
refrigerant while lithium bromide (Li
Br)/ammonia is used as the absorbent
•In the absorber, the lithium bromide
absorbs the water refrigerant, creating a
solution of water and lithium bromide
•Lithium bromide has great affinity for
water vapour, however, when the water.
lithium bromide solution is formed, they
are not completely soluble with each other

20. Advantage and Disdvantages
ADVANTAGES
There will be no fuel cost as the power plant runs by sun
energy
It doesn't cause pollution and global warming effects
It uses existing equipment like solar thermal mirrors, turbines
etc.
Can store energy using molten salts instead of using batteries
Uses less space than photovoltaics for same energy
generation output
Running costs of solar thermal are cheaper than coal or gas
plants
DISADVANTAGES
The initial capital costs for solar thermal is large
Uses lot of water which is major problem in desert areas
Usage of massive arrays of mirrors impacts the wildlife
species
These plants can be installed only in places which have
high amount of solar radiation
Solar thermal can't be installed in residential area
Build time would be longer than other forms of energy
generation

21. THANK YOU