The document discusses different types of solar collectors. It begins by introducing the basic working principle of solar collectors and defines key terms. It then describes two main categories of solar collectors: non-concentrating and concentrating. Under non-concentrating collectors it discusses flat plate collectors and evacuated tube collectors that are commonly used for domestic and industrial water heating. For concentrating collectors it explains parabolic trough collectors, heliostat field collectors, parabolic dish collectors, and Fresnel lens collectors. It also covers collector efficiency, solar radiations in India, and applications of solar collectors.

1. JIET GROUP OF INSTITUTION
JODHPUR INSTITUTE OF ENGINEERING & TECHNOLOGY
NH-65, NEW PALI ROAD, MOGRA,
JODHPUR (RAJ)
RAJASTHAN TECHNICAL UNIVERSITY, KOTA
2019-2020
PRESENTED BY
TANVEER SINGH SOLANKI
16EJIME098, IV YEAR
SOLAR COLLECTORS
1
NAME OF THE GUIDE
Prof. (Dr.) MANISH BAFNA

2. CONTENT
2
 Introduction
 Types of Solar Collectors
 Non-Concentrated Solar Collectors
 Flat Plate Collectors
 Evacuated Tube Collectors
 Concentrated Solar Collectors
 Parabolic Trough Collectors
 Heliostat Field Collectors
 Parabolic Dish Collectors
 Fresnel Lens Collectors
 Collector Efficiency
 Solar Radiations in India
 Applications

3. INTRODUCTION
Working principle of the solar collectors is based on the
transformation of the radiant energy of the sun into the thermal energy.
Solar energy collectors are special kinds of heat exchangers that
transform solar radiation energy to internal energy of the transport
medium.
The term solar collector refers to a device which, through the
sunlight absorption, collects heat by transferring it to a heat transfer
fluid (HTF) flowing inside the device.
The obtained energy is then exploited for different purposes. The
HTF is directly adopted for heating purposes [space heating or
industrial process heat (IPH) applications], stored, utilized for electricity
production through suitable power plants.
3

4. TYPES OF SOLAR COLLECTORS
Solar collectors are either Non-concentrating or
Concentrating.
In the Non-concentrating type, the collector area (i.e.
the area that intercepts the solar radiation) is the same as
the absorber area (i.e. the area absorbing the radiation).
In these types, the whole solar panel absorbs light.
Concentrating collectors have a bigger interceptor than
absorber.
4

5. For domestic/ industrial water heating purposes the solar collectors are
classified as:
1. FLAT PLATE SOLAR COLLECTORS.
AND
2. VACUUM/EVACUATED TUBE SOLAR COLLECTORS.
5
NON CONCENTRATED SOLAR
COLLECTORS

6. FLAT PLATE COLLECTORS
6

7. FLAT PLATE COLLECTORS
These collectors are simply metal boxes that have some sort of
transparent glazing as a cover on top of a dark-coloured absorber plate.
The sides and bottom of the collector are usually covered
with insulation to minimize heat losses to other parts of the collector.
Solar radiation passes through the transparent glazing material and hits
the absorber plate.
This plate heats up, transferring the heat to either water or air that is
held between the glazing and absorber plate.
Absorber plates are painted with special coatings designed to absorb
and retain heat better than traditional black paint & are made out of
metal that is a good conductor - usually copper or aluminum.
7

8. EVACUATED TUBE COLLECTORS
8

9. EVACUATED TUBE COLLECTORS
This type of solar collector uses a series of evacuated tubes to heat water
for use, these tubes utilize a vacuum, or evacuated space, to capture the
suns energy while minimizing the loss of heat to the surroundings.
 They have an inner metal tube which acts as the absorber plate, which is
connected to a heat pipe to carry the heat collected from the Sun to the
water.
This heat pipe is essentially a pipe where the fluid contents are under a
very particular pressure. At this pressure, the "hot" end of the pipe has
boiling liquid in it while the "cold" end has condensing vapour.
This allows for thermal energy to move more efficiently from one end of
the pipe to the other. Once the heat from the Sun moves from the hot end
of the heat pipe to the condensing end, the thermal energy is transported
into the water being heated for use.
9

10. CONCENTRATED SOLAR
COLLECTORS
1. PARABOLIC TROUGH COLLECTOR
2. HELIOSTAT FIELD COLLECTOR
3. PARABOLIC DISH COLLECTOR
4. FRESNEL LENS COLLECTOR
10

11. TYPES OF CONCENTRATED
SOLAR COLLECTORS
11
B) HELIOSTAT FIELD COLLECTOR
D) PARABOLIC TROUGH COLLECTOR
C) PARABOLIC DISH REFLECTOR
A) LINEAR FRESNEL COLLECTOR

12. PARABOLIC TROUGH COLLECTORS
Parabolic trough collectors are formed by a cylindrical surface of mirrors with a parabolic
shape that concentrates solar radiation on a receiver tube located at the focal point of the
parabola. A fluid, normally synthetic oil, circulates inside the receiver tubes and is heaten up
by the sun (around 400 ºC). The fluid is then pumped through heat exchangers to generate
steam which is thus used to produce electricity in a conventional turbine.
Main components of solar parabolic trough collectors are:
– Foundation and metallic structure: support the collectors and fix them to the ground so that the
whole structure can support the collector.
– Parabolic trough reflector: this is the concentrating part of the collector. It reflects the solar
radiation and transfers it to the receiver tube. Main reflective materials that are used include silver
and alluminium, which are normally placed on a glass plate.
– Absorber tube or receiver: it converts concentrated light energy into thermal energy in the heat
transfer fluid. It presents selective features to maximize energy conversion process.
– Transmission and tracking system: collectors moves so that their opening plane is pointed
towards the plane of sun rays. A tracking system is used to change and focus the collector as the sun
is moving.
– Heat transfer fluid: thermal oil is the most used working fluid in solar thermal plants. However,
different fluids as water steam can also be used. This fluid is the medium to transport the
concentrated thermal energy that permits to generate the steam to operate the turbine, thus producing
electricity.
12

13. HELIOSTAT FIELD COLLECTORS
For extremely high inputs of radiant energy, a multiplicity of flat
mirrors, or heliostats, using altazimuth mounts can be used to
reflect their incident direct solar radiation onto a common target.
This is called the heliostat field or central receiver collector.
By using slightly concave mirror segments on the heliostats, large
amounts of thermal energy can be directed into the cavity of a
steam generator to produce steam at high temperature and
pressure.
The concentrated heat energy absorbed by the receiver is
transferred to a circulating fluid that can be stored and later used to
produce power.
They collect solar energy optically and transfer it to a single
receiver, thus minimizing thermal energy transport requirements
13

14. PARABOLIC DISH COLLECTORS
14
A parabolic dish collector is a concentrating solar collector that is
similar in appearance to a large satellite dish, but has mirror-like
reflectors and an absorber at the focal point.
A parabolic dish system uses a computer and dual-axis tracking to
follow the Sun across the sky and concentrate the Sun's rays onto
the receiver located at the focal point in front of the dish. In some
systems, a heat engine, such as a Stirling engine, is linked to the
receiver to generate electricity.
Parabolic dish systems can reach 1000°C at the receiver, and
achieve the highest efficiencies for converting solar energy to
electricity in the small-power capacity range.

15. FRESNEL LENS COLLECTORS
Fresnel collectors have two variations: the Fresnel lens collector,
and the linear Fresnel reflector (LFR).
The collector is made from a plastic material and shaped in the
way shown to focus the solar rays to a point receiver, whereas the
reflector relies on an array of linear mirror strips that concentrate
light onto a linear receiver.
The LFR collector can be imagined as a broken-up parabolic
trough reflector, but unlike parabolic troughs, the individual strips
need not be of parabolic shape. The strips can also be mounted on
flat ground (field) and concentrate light on a linear fixed receiver
mounted on a tower. A representation of an element of an LFR
collector field.
In this case, large absorbers can be constructed and the absorber
does not have to move.
The greatest advantage of this type of system is that it uses flat or
elastically curved reflectors, which are cheaper than parabolic glass
reflectors. Additionally, these are mounted close to the ground, thus
15

16. COLLECTOR EFFICIENCY
16

17. SOLAR RADIATIONS IN INDIA
17

18. 18
India is ranked 11th in solar power generation in the world as on Jan. 2014.
Government funded solar energy in India only accounted for about 6.4 MW/yr of power
as of 2005.
In 2010 capacity of 25.1MW was added and 468.3MW in 2011.
In 2012 the capacity increase more than two times and become 1205 MW. During 2013
capacity added by 1114 MW and during 2014 capacity added by 313 MW.
In August 2015, the installed grid connected solar power capacity is 4.22 GW. The price
of solar energy has come down from Rs. 17.90 per unit in 2010 to about Rs. 7 per unit in
2015.
It is expected that with technology improvement and market competition solar power
will reach grid parity by 2017-18.
The Grid parity means the cost of electricity generated from alternative energy becomes
equal or less than the cost of purchasing power from the grid. Grid parity is very
important term in the solar system and preferably photovoltaic panel.
The Charanka Solar Park, at current installed capacity of 224 MW is the largest Solar
Park in Asia, was commissioned on April 19, 2012.
In India, Rajasthan has the largest share of solar power generation of 28.4% and
Gujarat share is 24.4% as on September 2015.

19. APPLICATIONS
The main use of this technology is in commercial buildings where hot water demand is
excessive due to frequent laundry washing.
Commercial applications include laundromats, car washes, military laundry facilities and eating
establishments.
The technology can also be used for space heating if the building is located off-grid or if utility
power is subject to frequent outages.
Solar water heating systems are most likely to be cost effective for facilities with water heating
systems that are expensive to operate, or with operations such as laundries or kitchens that require
large quantities of hot water.
Unglazed liquid collectors are commonly used to heat water for swimming pools but can also be
applied to large scale water pre-heating. Solar thermal systems are mostly used in residential and
industrial applications such as domestic water heating, heating of swimming pools, space heating,
water processes for industrial heating and agricultural drying. These products are reliable and
show a high technical standard for low temperature demand.
Concentrating collector systems are preferred technology in regions with more than 2,500
annual sunshine hours to obtain fluid temperatures above 150°C. The concentrator is normally
equipped with a tracking device that follows the sun with the absorber located along the focus to
extract the maximum amount of sunlight for heating.
Desalination plants, solar cookers.
19

20.  solareis.anl.gov
 https://www.researchgate.net.
 www.sciencedirect.com
 https://www.eia.gov/energyexplained/solar/solar-
thermal-collectors.php
 https://doi.org/10.1016/j.renene.2014.12.005
 www.ukessays.com
 en.wikipedia.org
20
REFERENCES

21. Thanks
21