6..solar energy storage

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Non Conventional Sources

Solar Energy Storages


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outline Difference between conventional and non-conventional energy How much solar energy received by earth ? What are Solar technologies?

Technical definition of Solar Energy? Thermal energy storage Different types of solar energy storages

->thermal energy storage-latent-sensible heat.. Water storage..pebble heat storage

->electrical storage-capacitor-inductor-battery storage

->chemical storage-chemical-thermo chemical storage->mechanical energy storage-pumping hydro electric-

compressed air-fly wheel.


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Conventional Sources (Renewable)

These are the commonly and widely used sourceseg. Hydroelectricity, Thermal Power (from coal,mineral oil, natural gas)

Non Conventional Sources(NonRenewable)

These are the new sources of energy, which are

still not in common use. Their contribution to thenational power is nominal.Eg. Solar, Tidal, Wind, Bio gas, Geo thermal.


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What is Solar Energy? Originates with the

thermonuclear fusionreactions occurring inthe sun.

Represents the entireelectromagneticradiation (visible light,

infrared, ultraviolet, x-rays, and radio waves).


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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 technologies are broadly characterized as either passive solar oractive solar depending on the way they capture, convert and distributesunlight

Active solar techniques include the use of photovoltaic panels, solarthermal collectors, with electrical or mechanical equipment, to convertsunlight into useful outputs.

Passive solar techniques include orienting a building to the Sun,

selecting materials with favorable thermal mass or light dispersingproperties, and designing spaces that naturally circulate air.
http://en.wikipedia.org/wiki/Passive_solarhttp://en.wikipedia.org/wiki/Active_solarhttp://en.wikipedia.org/wiki/Solar_thermal_energyhttp://en.wikipedia.org/wiki/Solar_thermal_energyhttp://en.wikipedia.org/wiki/Thermal_masshttp://en.wikipedia.org/wiki/Ventilation_%28architecture%29http://en.wikipedia.org/wiki/Ventilation_%28architecture%29http://en.wikipedia.org/wiki/Thermal_masshttp://en.wikipedia.org/wiki/Solar_thermal_energyhttp://en.wikipedia.org/wiki/Solar_thermal_energyhttp://en.wikipedia.org/wiki/Active_solarhttp://en.wikipedia.org/wiki/Passive_solar


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Solar Energy: The energy transmitted from the Sun. The

upper atmosphere of Earth receives about 1.5

1021 watt-hours (thermal) of solarradiation annually. This vast amount ofenergy is more than 23,000 times that usedby the human population of this planet, but it

is only about one two-billionth of the Sun'smassive outpouringabout 3.9 102MW


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There are four primary ways tostore solar thermal energy:

(1) sensible-heat-storage systems, which store thermalenergy in materials with good heat-retentionqualities;

(2) latent-heat-storage systems, which store solarthermal energy in the latent heat of fusion orvaporization of certain materials undergoing achange of phase;

(3) chemical energy storage, which uses reversiblereactions (for example, the dissociation-association

reaction ofsulfuric acid and water); and(4) electrical or mechanical storage, particularly through

the use of storage batteries (electrical) orcompressed air (mechanical)Energy storage.
http://www.answers.com/topic/heat-of-fusionhttp://www.answers.com/topic/heat-of-fusionhttp://www.answers.com/topic/sulfuric-acidhttp://www.answers.com/topic/sulfuric-acidhttp://www.answers.com/topic/energy-storagehttp://www.answers.com/topic/energy-storagehttp://www.answers.com/topic/energy-storagehttp://www.answers.com/topic/sulfuric-acidhttp://www.answers.com/topic/heat-of-fusion


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sensible heat storagea heat storage system that operates on the basis of a changein the temperature (but not the state) of the storage medium

(e.g., water).


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Sensible heat storage with air as the energy transport

mechanism, rock, gravel, or crushed stone in a bin has the

advantage of providing a large, cheap heat transfer

surface.

1.Rock is more easily contained than water.

2.Rock acts as its own heat exchanger

3.It can be used for thermal storage at high temperatures,

much higher than 100*c

4.the heat transfer coefficients between the air and solidis high.

5.The cost of storage material is low.

6.The conductivity of the bed is low when air flow is not

present.

Pebble bed exchanger have good heat

transfer characteristics between air and the solids of the

bed. This type of storage system has been used in the

solar houses or with hot air collector system.


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Latent heat is the energy absorbed or released when

a substance changes its physical state.

Latent heat is absorbed upon evaporation, and

released upon condensation to liquid (as in clouds).

Latent heat is also absorbed when water melts, andreleased when it freezes.


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B Co-Generator UnitProvides heat (and electricity) when passive solar

heat or photovoltaic (PV) generated electricity is

insufficient.

L BatteriesSufficient electrical energy storage for 4 days

without sunshine.

K Solar Photovoltaic PanelsProvides approx. 80% of electrical requirements.


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CHEMICAL ENERGY STORAGE:


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Certain organ metallic molecules undergo a reaction upon exposure to lightthat is reversible with either a catalyst or heat. In some cases a considerableamount of energy can be stored, as was shown for example in the work ofVollhardt in 1996 for fulvalenes. In the Ru case shown in this figure, the Ru-Ru bond and the C-C bond are broken upon light exposure, and the moleculeeffectively flips. This stored chemical energy is highly stable, with a largeback-reaction barrier, and can then be released in a very straightforwardmanner. To understand how and why this reaction takes place, and also howthe efficiency of the reaction in order to increase its ability to store energy. Anumber of other such molecules that fall into the same class of sunlight-to-chemical energy storage. Were also exploring pathways for utilizing suchmolecules on large scales, which involve appropriate matrix materials (whichin turn impact its chemical properties).


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To pump water from one reservoir to another

reservoir at a higher level. During periods of peak

electrical demand, water from the higher reservoiris released through turbines to the lower reservoir

and electricity is produced. These systems use

more electricity to pump than they can produce.

Typical power rating on these systems is between

100

2000 MW with a typical energy ratingbetween 4 10 hours.


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In compressed air energy storage, is used to pumpair (1) to a high pressure (2) into a sealedunderground cavern. (3) as the air in the cavern is

slowly heated and released; the resulting powerproduced by the generator (4) may be used atpeak hours.

Typical power rating on these systems is between100 300 MW with a typical energy rating between6 20 hours


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1. A flywheel is an electromechanical

device that couples a motor generatorwith a rotating mass to store energy forshort durations

2. flywheels constructed from carbon fibermaterials and magnetic bearings canspin in vacuum at speeds up to 40,000

to 60,000 RPM.


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CONCLUSION:

Solar energy is a clean, pollution free and renewable source of energy. To make sure we have plenty of energy in the future, it's up to all of us

to use energy wisely. We must all conserve energy and use itefficiently. It's also up to those who will create the new energytechnologies of the future.

All energy sources have an impact on the environment. Concernsabout the greenhouse effect and global warming, air pollution, andenergy security have led to increasing interest and more developmentin renewable energy sources such as solar, wind, geothermal, wavepower and hydrogen.

But we'll need to continue to use fossil fuels and nuclear energy until

new, cleaner technologies can replace them. One of you who is readingthis might be another The future is ours, but we need energy to get there.


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Imagination is more important than knowledge, for

knowledge is limited, whereas imagination embraces theentire world - stimulating progress, giving birth to evolution.

- Albert Einstein

Quotes:

6..solar energy storage

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