1. A PRESENTAION ON : SOLAR ENERGY AND ITS APPLICATIONS
2. Solar energy The sun is a source of enormous energy which is
at a distance of about 150 x 106 km from earth. The energy from the
sun in form of radiation is called solar energy. It is estimated
that with 0.1 % of 75,000 trillion kWH of solar energy that reaches
the earth, the planets requirements can be easily fulfilled.
3. 1. Solar water heater Solar water heaters use the sun's heat
to provide hot water for a home or building. A typical 100 LPD
(litre per day) system is sufficient to provide approximately 100
litres of hot water at an average temperature of 65C every day on
all sunny days. A typical direct solar thermal system consists of
collector, pipes and an insulated tank. There are two types of
collectors used in a solar hot water service: 1. flat plate
collectors 2. evacuated tubes
4. Flat Plate Collector system
5. Evacuated Vacuum Tube system
6. 2. Solar Cooker 1. A solar cooker consists of a rectangular
wooden box which is lined from inside with some insulation
material, such as thermocol or glass wool. The insulating material
prevents heat losses due to conduction and convection. 2. Within
the wooden box is placed a light fitting metallic box, whose inner
surface is painted black, as black surface are good absorbers a
heat energy.
7. Solar ponds are large-scale energy collectors with integral
heat storage for supplying thermal energy. The solar pond works on
a very simple principle. It is well known that water or air is
heated they become lighter and rise upward e.g. a hot air balloon.
Similarly, in an ordinary pond, the suns rays heat the water and
the heated water from within the pond rises and reaches the top but
loses the heat into the atmosphere. 3. Solar pond
8. 5. A solar pond has three zones. The top zone is the surface
zone, or UCZ (Upper Convective Zone), which is at atmospheric
temperature and has little salt content. 6. The bottom zone is very
hot, 70 85 C, and is very salty. It is this zone that collects and
stores solar energy in the form of heat, and is, therefore, known
as the storage zone or LCZ (Lower Convective Zone). 7. Separating
these two zones is the important gradient zone or NCZ
(Non-Convective Zone). Here the salt content increases as depth
increases, thereby creating a salinity or density gradient. 8. This
gradient zone acts as a transparent insulator permitting sunlight
to reach the bottom zone but also entrapping it there. The trapped
(solar) energy is then withdrawn from the pond in the form of hot
brine from the storage zone. 9. Though solar ponds can be
constructed anywhere, it is economical to construct them at places
where there is low cost salt and bittern, good supply of sea water
or water for filling and flushing, high solar radiation, and
availability of land at low cost. Coastal areas in Tam
9. The first solar pond in India (6000 m) was built at Bhuj.
The project was sanctioned under the National Solar Pond Programme
by the Ministry of Non-Conventional Energy Sources in 1987 and
completed in 1993. The solar pond successfully demonstrated the
expediency of the technology by supplying 80,000 litres of hot
water daily to the plant. Solar pond
10. I. A solar cell, or photovoltaic cell (PV), is an
electrical device that converts the energy of light directly into
electricity by the photovoltaic effect. II. It works on the
principle of photoelectric effect- when light falls on certain
metals like silicon, the electron gets excited and escape from
metal, which are then collected by another metal and passed through
wires in a stream; the electron flow thus constitutes the electric
current. III. Photovoltaic (PV) cells are made of semiconducting
materials such as silicon. There are two basic types of
semiconductor material, called positive (or P type) and negative
(or N type). 4. (i) Solar electricity-photovoltaic
11. Photovoltaic cell
12. 6. Solar refrigerator 1. Solar refrigerators can be
classified into two types: Solar refrigerators that use batteries
and ones that dont. 2. A solar fridge that uses batteries uses a
combination of solar panels and lead batteries. The batteries serve
as back up overnight and on sunless days. These fridges have many
disadvantages. These are expensive; the batteries are heavy and
deteriorate quickly in hot climates. 3. Solar power fridges that
dont require batteries can be made from basic household materials.
These are modern and better suited to developing countries.
Although these fridges are technically solar powered, they dont use
solar panels for power. They rely on conduction, convection and
evaporation and operates at an even 6Celsius.
13. World Scenario of Solar energy As of January 2015, the
largest solar power plants in the world are: For PV, the 550 MW
Desert Sunlight Solar Farm and 550 MW Topaz Solar Farm, both
located in southern California. For CSP (solar thermal), the 377 MW
Ivanpah Solar Power Facility, located in California's Mojave
Desert. Other large solar thermal power stations include the 35
(MW) solar energy generating systems power installation in the USA,
Solnova solar Power Station (Spain, 150 MW), Andasol solar power
station (Spain, 150 MW) and the first part of Shams solar power
station (United Arab Emirates, 100 MW). Other large PV farms
include the 320 MW Longyangxia Dam Solar Park in China, the 224 MW
Charnka Solar Park and the 166 MW Solapark Meuro in Germany.
14. UNESCO REPORT
15. 1. India is densely populated and has high solar
insolation, an ideal combination for using solar power in India. 2.
In the solar energy sector, some large projects have been proposed,
and a 35, 000 km2 area of the Thar Desert has been set aside for
solar power projects, sufficient to generate 700 to 2,100 GW. 3. In
July 2009, India unveiled a US$19 billion plan to produce 20 GW of
solar power by 2020. Under the plan, the use of solar-powered
equipment and applications would be made compulsory in all
government buildings, as well as hospitals and hotels. 4. In
January 2015, the Indian government significantly expanded its
solar plans, targeting US$100 billion of investment and 100 GW of
solar capacity by 2022. 5. In India 10,000 domestic and 5,000
industrial solar water heating systems have been developed. Indian
Scenario of Solar energy