Solar energy is generated from sunlight using photovoltaic cells or concentrated solar power systems. Photovoltaic cells use the photovoltaic effect to directly convert sunlight into electricity, while concentrated solar power systems use lenses or mirrors to focus sunlight onto a receiver to generate electricity. Solar energy can be used to power buildings, vehicles, and electric grids, providing a renewable alternative to fossil fuels. However, the intermittent nature of sunlight presents challenges for energy storage and solar only produces electricity when the sun is shining.

1. Solar EnergySolar Energy
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N.YaminiN.Yamini
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e-technoe-techno
Narayana e-TechnoNarayana e-Techno
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2. Solar Energy:Solar Energy:
The Ultimate RenewableThe Ultimate Renewable
ResourceResource

3. What is Solar Power?What is Solar Power?
o Solar power is the conversion of sunlight
into electricity, either directly
using photovoltaic (PV) or indirectly
using concentrated solar power(CSP)
o Concentrated solar power systemsConcentrated solar power systems
use lenses or mirrors and trackinguse lenses or mirrors and tracking
systems to focus a large area of sunlight intosystems to focus a large area of sunlight into
a small beam.a small beam.

4. How much solar energy?How much solar energy?
The surface receives about 47% of the total solar
energy that reaches the Earth. Only this amount is
usable.

5. Solar Power Generation SystemSolar Power Generation System

6. cont…Solar Plantcont…Solar Plant

7. How To Manufacture?How To Manufacture?
 Solar panel comprises solar cells.Solar panel comprises solar cells.
 Solar Cell:Solar Cell:
Solar cells produce direct current electricitySolar cells produce direct current electricity
from sun light.from sun light.
Solar cells are based uponSolar cells are based upon
PHOTOVOLTAIC EFFECT.PHOTOVOLTAIC EFFECT.

8. PHOTOVOLTAIC EFFECTPHOTOVOLTAIC EFFECT
 The photovoltaic effect is the creation of aThe photovoltaic effect is the creation of a
voltage (or a corresponding electric current) in avoltage (or a corresponding electric current) in a
material upon exposure to light.material upon exposure to light.
 The photovoltaic effect is that the generatedThe photovoltaic effect is that the generated
electrons are transferred between differentelectrons are transferred between different
bands (i.e., from the valence to conductionbands (i.e., from the valence to conduction
bands) within the material, resulting in thebands) within the material, resulting in the
buildup of a voltage between two electrodes.buildup of a voltage between two electrodes.

9. Direct Conversion into ElectricityDirect Conversion into Electricity
 A simple wafer of siliconA simple wafer of silicon
with wires attached to thewith wires attached to the
layers. Current is producedlayers. Current is produced
based on types of siliconbased on types of silicon
(n- and p-types) used for(n- and p-types) used for
the layers. Each cell=0.5the layers. Each cell=0.5
volts.volts.
 Battery needed as storageBattery needed as storage
 They are exposed to theThey are exposed to the
weather, their lifespan isweather, their lifespan is
about 20 years.about 20 years.

10. PHOTOVOLTAICPHOTOVOLTAIC
APPLICATION…APPLICATION…
 Power stationsPower stations
Many solar photovoltaic power stations haveMany solar photovoltaic power stations have
been built, mainly in Europe. As of Decemberbeen built, mainly in Europe. As of December
2010, the largest photovoltaic (PV) power plants2010, the largest photovoltaic (PV) power plants
in the world is the Sarnia Photovoltaic Powerin the world is the Sarnia Photovoltaic Power
Plant(Canada, 97 MW)Plant(Canada, 97 MW)

11.  In buildingsIn buildings
Photovoltaic arrays are often associated withPhotovoltaic arrays are often associated with
buildings: either integrated into them, mountedbuildings: either integrated into them, mounted
on them.on them.
In 2010, more than four-fifths of the 9,000In 2010, more than four-fifths of the 9,000
MW of solar PV operating in Germany wasMW of solar PV operating in Germany was
installed on rooftops.installed on rooftops.

12. Parking MeterParking Meter
 Standalone devicesStandalone devices
1.1. Water pumps Water pumps
2. Parking meters Parking meters
3. Emergency telephones3. Emergency telephones
4 Temporary traffic signs,4 Temporary traffic signs,

13. PERFORMANCE OF PVPERFORMANCE OF PV
 TemperatureTemperature
Generally, temperatures above roomGenerally, temperatures above room
temperature reduce the performance oftemperature reduce the performance of
photovoltaic.photovoltaic.
 Optimum Orientation of Solar PanelsOptimum Orientation of Solar Panels
For best performance, terrestrial PV systemsFor best performance, terrestrial PV systems
aim to maximize the time they face the sun.aim to maximize the time they face the sun.

14. Solar Electricity:Solar Electricity:
Parabolic DishesParabolic Dishes
 Focus a large area of sunlight on a smaller receiverFocus a large area of sunlight on a smaller receiver
for each device to generate electricity.for each device to generate electricity.
 Efficiency of this system was 25%.Efficiency of this system was 25%.
 The more recent facilities converted a remarkableThe more recent facilities converted a remarkable
22% of sunlight into electricity.22% of sunlight into electricity.

15. Parabolic Dishes and TroughsParabolic Dishes and Troughs
Because they work best under direct sunlight,
parabolic dishes and troughs must be steered
throughout the day in the direction of the sun.
Collectors in southern CA.

16. STORAGE & DISTRIBUTIONSTORAGE & DISTRIBUTION
 Solar energy is not available at night, makingSolar energy is not available at night, making
energy storage an important issue in order toenergy storage an important issue in order to
provide the continuous availability of energyprovide the continuous availability of energy
 Solar energy can be stored at highSolar energy can be stored at high
temperatures using molten salts. Salts are antemperatures using molten salts. Salts are an
effective storage medium because they areeffective storage medium because they are
low-cost, have a high specific heat capacitylow-cost, have a high specific heat capacity
and can deliver heat at temperaturesand can deliver heat at temperatures
compatible with conventional power systems.compatible with conventional power systems.

17.  Off-grid PV systems have traditionallyOff-grid PV systems have traditionally
used rechargeable batteries to store excess electricity.used rechargeable batteries to store excess electricity.
With grid-tied systems, excess electricity can be sent toWith grid-tied systems, excess electricity can be sent to
the transmission grid.the transmission grid.

18. ADVANTAGESADVANTAGES
 Solar power is pollution-free during use. ProductionSolar power is pollution-free during use. Production
end-wastes and emissions are manageable using existingend-wastes and emissions are manageable using existing
pollution controls.pollution controls.
 PV installations can operate for many years with littlePV installations can operate for many years with little
maintenance or intervention after their initial set-up.maintenance or intervention after their initial set-up.
 Grid-connected solar electricity can be used locally thusGrid-connected solar electricity can be used locally thus
reducing transmission/distribution losses.reducing transmission/distribution losses.

19. DISADVANTAGESDISADVANTAGES
 Photovoltaic cells are costly to install.Photovoltaic cells are costly to install.
 Solar electricity is not produced at night and is muchSolar electricity is not produced at night and is much
reduced in cloudy conditions. Therefore, a storage orreduced in cloudy conditions. Therefore, a storage or
complementary power system is required.complementary power system is required.
 Solar cells produce DC which must be convertedSolar cells produce DC which must be converted
to AC (using a grid tie inverter).to AC (using a grid tie inverter).
 Sun does not shine consistentlySun does not shine consistently

20. EFFICIENCYEFFICIENCY
 Overall, the efficiency is about 10-14%.Overall, the efficiency is about 10-14%.
 Efficiency is far lass than the 77% of solarEfficiency is far lass than the 77% of solar
spectrum with usable wavelengths.spectrum with usable wavelengths.
 43% of photon energy is used to warm the crystal.43% of photon energy is used to warm the crystal.
 Efficiency drops as temperature increases (fromEfficiency drops as temperature increases (from
24% at 0°C to 14% at 100°C.)24% at 0°C to 14% at 100°C.)
 Light is reflected off the front face and internalLight is reflected off the front face and internal
electrical resistance are other factors.electrical resistance are other factors.

21. Thank You.Thank You.