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Solar Energy Solar Energy Submitted by Submitted by N.Yamini N.Yamini 7 7 th th e-techno e-techno Narayana e- Narayana e- Techno school Techno school
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Page 1: Solarpower

Solar EnergySolar Energy

Submitted bySubmitted by

N.YaminiN.Yamini 77thth e-techno e-techno

Narayana e-Techno Narayana e-Techno schoolschool

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Solar Energy: Solar Energy: The Ultimate The Ultimate Renewable Renewable ResourceResource

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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 systems Concentrated solar power systems use lenses or mirrors and tracking use lenses or mirrors and tracking systems to focus a large area of systems to focus a large area of sunlight into a small beam.sunlight into a small beam.

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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.

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Solar Power Generation Solar Power Generation SystemSystem

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cont…Solar Plantcont…Solar Plant

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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 Solar cells produce direct current electricity from sun light.electricity from sun light.

Solar cells are based upon Solar cells are based upon

PHOTOVOLTAIC EFFECT.PHOTOVOLTAIC EFFECT.

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PHOTOVOLTAIC EFFECTPHOTOVOLTAIC EFFECT

The photovoltaic effect is the creation of The photovoltaic effect is the creation of a voltage (or a corresponding electric a voltage (or a corresponding electric current) in a material upon exposure to current) in a material upon exposure to light.light.

  The photovoltaic effect is that the The photovoltaic effect is that the generated electrons are transferred generated electrons are transferred between different bands (i.e., from the between different bands (i.e., from the valence to conduction bands) within the valence to conduction bands) within the material, resulting in the buildup of a material, resulting in the buildup of a voltage between two electrodes.voltage between two electrodes.

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Direct Conversion into Direct Conversion into ElectricityElectricity

A simple wafer of silicon A simple wafer of silicon with wires attached to with wires attached to the layers. Current is the layers. Current is produced based on types produced based on types of silicon (n- and p-types) of silicon (n- and p-types) used for the layers. Each used for the layers. Each cell=0.5 volts.cell=0.5 volts.

Battery needed as Battery needed as storagestorage

They are exposed to the They are exposed to the weather, their lifespan is weather, their lifespan is about 20 years.about 20 years.

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PHOTOVOLTAIC PHOTOVOLTAIC APPLICATION…APPLICATION…

Power stationsPower stations

Many solar photovoltaic power Many solar photovoltaic power stations have been built, mainly in stations have been built, mainly in Europe. As of December 2010, the Europe. As of December 2010, the largest photovoltaic (PV) power largest photovoltaic (PV) power plants in the world is the Sarnia plants in the world is the Sarnia Photovoltaic Power Plant(Canada, 97 Photovoltaic Power Plant(Canada, 97 MW)MW)

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In buildingsIn buildings

Photovoltaic arrays are often Photovoltaic arrays are often associated with buildings: either associated with buildings: either integrated into them, mounted on integrated into them, mounted on them.them.

In 2010, more than four-fifths of the In 2010, more than four-fifths of the 9,000 MW of solar PV operating in 9,000 MW of solar PV operating in Germany was installed on rooftops.Germany was installed on rooftops.

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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,

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PERFORMANCE OF PVPERFORMANCE OF PV

TemperatureTemperature

Generally, temperatures above room Generally, temperatures above room temperature reduce the performance of temperature reduce the performance of photovoltaic.photovoltaic.

Optimum Orientation of Solar PanelsOptimum Orientation of Solar Panels

For best performance, terrestrial PV For best performance, terrestrial PV systems aim to maximize the time they systems aim to maximize the time they face the sun.face the sun.

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Solar Electricity:Solar Electricity:Parabolic Dishes Parabolic Dishes

Focus a large area of sunlight on a Focus a large area of sunlight on a smaller receiver for each device to smaller receiver for each device to generate electricity.generate electricity.

Efficiency of this system was 25%.Efficiency of this system was 25%.

The more recent facilities converted a The more recent facilities converted a remarkable 22% of sunlight into remarkable 22% of sunlight into electricity. electricity.

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Parabolic Dishes and Parabolic Dishes and TroughsTroughs

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.

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STORAGE & STORAGE & DISTRIBUTIONDISTRIBUTION

Solar energy is not available at night, Solar energy is not available at night, making energy storage an important issue making energy storage an important issue in order to provide the continuous in order to provide the continuous availability of energyavailability of energy

Solar energy can be stored at high Solar energy can be stored at high temperatures using molten salts. Salts are temperatures using molten salts. Salts are an effective storage medium because they an effective storage medium because they are low-cost, have a high specific heat are low-cost, have a high specific heat capacity and can deliver heat at capacity and can deliver heat at temperatures compatible with temperatures compatible with conventional power systems.conventional power systems.

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

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ADVANTAGESADVANTAGES

Solar power is pollution-free during use. Solar power is pollution-free during use. Production end-wastes and emissions are Production end-wastes and emissions are manageable using existing pollution controls.manageable using existing pollution controls.

PV installations can operate for many years PV installations can operate for many years with little maintenance or intervention after with little maintenance or intervention after their initial set-up.their initial set-up.

Grid-connected solar electricity can be used Grid-connected solar electricity can be used locally thus reducing transmission/distribution locally thus reducing transmission/distribution losses.losses.

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DISADVANTAGESDISADVANTAGES

Photovoltaic cells are costly to install.Photovoltaic cells are costly to install.

Solar electricity is not produced at night Solar electricity is not produced at night and is much reduced in cloudy conditions. and is much reduced in cloudy conditions. Therefore, a storage or complementary Therefore, a storage or complementary power system is required.power system is required.

Solar cells produce DC which must be Solar cells produce DC which must be converted to AC (using a grid tie inverter).converted to AC (using a grid tie inverter).

Sun does not shine consistentlySun does not shine consistently

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EFFICIENCYEFFICIENCY Overall, the efficiency is about 10-14%.Overall, the efficiency is about 10-14%.

Efficiency is far lass than the 77% of solar Efficiency 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 43% of photon energy is used to warm the crystal.crystal.

Efficiency drops as temperature increases Efficiency drops as temperature increases (from 24% at 0°C to 14% at 100°C.)(from 24% at 0°C to 14% at 100°C.)

Light is reflected off the front face and Light is reflected off the front face and internal electrical resistance are other internal electrical resistance are other factors.factors.

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Thank You.Thank You.