Solar power captures radiant light and heat from the sun and converts it into clean energy that can be used to power homes, businesses and machinery.

1. Solar
Energy
Presented By: ZainabArshad
BS Hons, Environmental Sciences
UniversityOf Gujrat, Pakistan
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2. What is Solar Energy?
• Energy produced
by the sun
• Clean, renewable
source of energy
• Harnessed by
solar collection
methods such as
solar cells
• Converted into
usable energy
such as electricity
Photovoltaic (solar)
panel
Set of solar panels
Sun and electrical
power lines
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3. Brief Introduction
• Solar power captures radiant light and heat from the sun and
converts it into clean energy that can be used to power homes,
businesses and machinery.
• This renewable energy source, first used commercially more
than 100 years ago, is growing rapidly as people look for
sources of energy that are sustainable and environmentally
sound both in industrial nations like the
United States and third world countries
that need to power growth.
• In fact, solar power is expected to
become the world’s biggest source of
electricity by 2050, according to the
International Energy Agency.
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4. • Originates with the
thermonuclear
fusion reactions
occurring in the sun.
• Represents the
entire
electromagnetic
radiation (visible
light, infrared,
ultraviolet, x-rays,
and radio waves).
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5. So, why solar power?
 With the amount of solar energy the planet receives
we have the potential to provide at least 1,000 times
the energy consumed globally. (in 2008)
 On a sunny day the sun gives off 1,000 watts of
energy to the earths surface per square meter
 Sunlight is infinite, unlike many of our other energy
sources
 Solar energy is absorbed at earth’s surface at an
average rate of 90,000 TW, which is about 7,000 times
the total global demand of energy.

6. How much solar energy?
The surface receives about 47% of the total
solar energy that reaches the Earth. Only this
amount is usable.
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7. Advantages
• All chemical and radioactive
polluting byproducts of the
thermonuclear reactions remain
behind on the sun, while only pure radiant
energy reaches the Earth.
• Energy reaching the earth is incredible. By
one calculation, 30 days of sunshine striking
the Earth have the energy equivalent of the
total of all the planet’s fossil fuels, both used
and unused!
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8. • Solar panel systems are a great way for you
to save money, no matter what your budget
is.
• Solar power systems can produce electricity
for 25 or more years.
• Solar energy systems are tied to the electric
grid and do not require batteries to store
power.
• Solar photovoltaic
systems have been
around for a
long time.
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9. Disadvantages
• Sun does not shine consistently.
• Solar energy is a diffuse source. To harness
it, we must concentrate it into an amount and
form that we can use, such as heat and
electricity.
• Addressed by approaching the problem
through:
1) collection, 2) conversion, 3) storage.
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10. Solar Cells are Converters of
Energy…
• Solar cells are devices
that take light energy
as input and convert it
into electrical energyLight energy
Solar cell -
converts light
energy to
electricity
Electrical energy (carried
through wires)
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11. • Solar Energy System or Solar Power System,
is a stand-alone system, entirely powered by
solar energy to harness different types of
energies.
• Solar Energy System are broadly
characterized as either
Passive Solar or Active
Solar depending on
the way they
capture, convert
and distribute
solar energy.
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12. Active Solar Energy Systems
• Active Solar Energy Systems include the use of photovoltaic
panels and solar thermal collectors to harness the energy.
• Active Solar Energy Systems use the same principles as passive
systems except that they use a fluid (such as water to absorb
the heat) and some electrical or mechanical equipment (such as
pumps and fans) to increase the usable heat in a system.
A solar collector positioned on the roofs
of buildings heats the fluid and then
pumps it through a system of pipes
to heat the whole building.
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13. Passive Solar Energy Systems
• Passive Solar Energy Systems include orienting a building to
the Sun, selecting materials with favorable thermal mass or
light dispersing properties, and designing
spaces that naturally circulate air.
• Ancient people used passive solar energy
systems. They build their houses out of
stone or clay, which absorbed the sun’s
heat during the day and stayed warm
after dark, providing heat throughout
the night.
• effective methods of passive solar energy capture include
using stone flooring and walls with thick insulation to keep
the energy in buildings. With carefully placed windows and
other architectural techniques, passive solar energy systems
can be an effective way to heat buildings
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14. Environmental impacts
Solar Energy provide significant environmental benefits
when compared to the conventional energy sources,
contributing to the sustainable development. The use of
SE has positive environmental implications such as :
• reduction of the CO2 emissions;
• improvement of the quality of
water supplies;
• reclamation of degraded land;
• reduction of the number of the
required power transmission
lines.
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15. socio-economic impacts
From the socio-economic viewpoint the benefits of the use of
SE include:
• reduction of the national
dependency on fuel imports;
• diversification and security of
energy supply;
• provision of significant job
opportunities and working
positions;
• support of the energy market deregulation;
• acceleration of the rural electrification in developing
countries.
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16. Effect on buildings
• The addition to the building fabric may increase the
fire risk –theoretically-, and the water intrusion into
the roof space
• SE is a viable technology in an urban
environment, to replace the existing
building’s cladding materials.
Also, PV panels can be directly
used into the façade
of a building instead
of mirrors.
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17. Social impact
• Some direct benefits are related to lighting for
domestic and community activities and mainly to the
opportunity to suburban and borderland’s habitants
to have access to computers, lighting, radio and
phone.
• Therefore SET improves the
quality of life and reduces
migration. During
installation and
maintenance full- and
part-time jobs creation
improves local
microeconomics and drives to poverty alleviation
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18. Solar collectors
• A solar collector is a device that transforms solar
radiation from the Sun into heat, which is then
transferred to some fluid. These devices are primarily
used for active solar heating and allow for the heating of
water for personal use.
• These collectors are generally
mounted on the roof
and must be very
Sturdy as they are
exposed to a variety
of different weather
conditions.
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19. • A solar collector is basically
a flat box and are composed
of three main parts, a
transparent cover, tubes
which carry a coolant and
an insulated back plate.
• The solar collector works on
the green house effect principle;
solar radiation incident upon
the transparent surface of the
solar collector is transmitted through though this surface.
• The inside of the solar collector is usually evacuated, the
energy contained within the solar collect is basically
trapped and thus heats the coolant contained within the
tubes.
• The tubes are usually made from copper, and the back
plate is painted black to help absorb solar radiation. The
solar collector is usually insulated to avoid heat losses.
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20. Photovoltaic
• A photovoltaic system, also PV system or solar
power system, is a power system designed to supply
usable solar power by means of photovoltaic.
• It consists of an arrangement of several components,
including solar panels to absorb and convert sunlight
into electricity, a solar inverter to change the electric
current from DC to AC, as well as mounting, cabling,
and other electrical accessories to set up a working
system.
• PV systems range from small, rooftop-mounted or
building-integrated systems with capacities from a
few to several tens of kilowatts, to large utility-scale
power stations of hundreds of megawatts.
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21. http://www.fsec.ucf.edu/en/consumer/solar_electricity/basics/how_pv_system_works.htm
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22. Solar thermal generators
• A solar thermal generator based on fresnel mirrors
can create very efficient, relatively cost-efficient solar
harvesting in the right regions. Here I cover a system
supplying utility needs and another aimed at
commercial clients.
• The construction of each is different. Proposed and
existing useful locations are also different.
• These are large construction pieces. They are
planned to be located in large desert-type areas as
near to the equator as possible to improve solar
efficiency. Places like the western USA, Chile,
western central Australia, the Midddle East, South
Africa and Namibia are promoted as best sites.
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23. • Practically all utility-scale solar thermal arrays
throughout the world are based on parabolic mirrors -
long "U"-shaped dishes maximally focusing the sun's
rays.
• The focal point of the mirrors has a collecting unit,
usually a pipe containing water or some similar
collecting fluid which can then be fed to power-
generating turbines.
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24. Conclusions
• Argument that sun provides power only during the
day is countered by the fact that 70% of energy
demand is during daytime hours. At night,
traditional methods can be used to generate the
electricity.
• Goal is to decrease our dependence on fossil fuels.
• Currently, 75% of our electrical power is generated by
coal-burning and nuclear power plants.
• Mitigates the effects of acid rain, carbon dioxide, and
other impacts of burning coal and counters risks
associated with nuclear energy.
• pollution free, indefinitely sustainable.

25. References
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energy, 77(5), 445-459.
• Collares-Pereira, M., & Rabl, A. (1979). The average distribution of solar radiation-correlations
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energy, 22(2), 155-164.
• Chow, C. W., Urquhart, B., Lave, M., Dominguez, A., Kleissl, J., Shields, J., & Washom, B. (2011).
Intra-hour forecasting with a total sky imager at the UC San Diego solar energy testbed.
Solar Energy, 85(11), 2881-2893.
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• Hottel, H. C. (1976). A simple model for estimating the transmittance of direct solar radiation
through clear atmospheres. Solar energy, 18(2), 129-134.
• Liu, B. Y., & Jordan, R. C. (1963). The long-term average performance of flat-plate solar-energy
collectors: with design data for the US, its outlying possessions and Canada. Solar energy,
7(2), 53-74.
• Scaife, D. E. (1980). Oxide semiconductors in photoelectrochemical conversion of solar energy.
Solar Energy, 25(1), 41-54.
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