DONE BY AMEENAH KHAN

09/0509/1391

ENERGYENERGY

It is the ability to do work.It is the ability to do work. In physics, work is done when a force applied In physics, work is done when a force applied

to an object which moves it some distance in to an object which moves it some distance in the direction of the force.the direction of the force.

Mathematically, W = Fs, where W is the work Mathematically, W = Fs, where W is the work done, F is the force applied, and s is the done, F is the force applied, and s is the distance moved.distance moved.

DIFFERENT ENERGY SOURCESDIFFERENT ENERGY SOURCES

‘‘Traditional’ fuels such as fuel wood, crop Traditional’ fuels such as fuel wood, crop wastes, and animal dung.(non-commercial)wastes, and animal dung.(non-commercial)

Fossil fuels such as coal, oil and natural gas Fossil fuels such as coal, oil and natural gas (commercial ‘traditional’ fuels)(commercial ‘traditional’ fuels)

Non-traditional renewable energy sources as Non-traditional renewable energy sources as hydro, modern biomass, solar, wind, ocean and hydro, modern biomass, solar, wind, ocean and geothermal.geothermal.

ENERGY FORMSENERGY FORMS

SOLARSOLAR WATERWATER WINDWIND GEOTHERMALGEOTHERMAL

SOLAR ENERGYSOLAR ENERGY

WHAT IS SOLAR ENERGY? WHAT IS SOLAR ENERGY?

It is the radiation from the sun that is capable of It is the radiation from the sun that is capable of producing heat, causing chemical reactions, or producing heat, causing chemical reactions, or generating electricity.generating electricity.

It is the largest source of energy received on Earth, It is the largest source of energy received on Earth, but its intensity on the earth’s surface is quite low.but its intensity on the earth’s surface is quite low.

Solar energy is rapidly becoming the ultimate energy Solar energy is rapidly becoming the ultimate energy source because of its non-polluting character and its source because of its non-polluting character and its inexhaustible supply which are in stark contrast to inexhaustible supply which are in stark contrast to such fossil fuel sources as coal, oil, and natural gas.such fossil fuel sources as coal, oil, and natural gas.

COMPOSITIONCOMPOSITION

The Sun emits EM radiation across most of the The Sun emits EM radiation across most of the electromagnetic spectrumelectromagnetic spectrum The Sun does, however, emit The Sun does, however, emit X-raysX-rays, , ultravioletultraviolet, , visible lightvisible light , , infraredinfrared

, and even , and even Radio wavesRadio waves.When ultraviolet radiation is not absorbed by .When ultraviolet radiation is not absorbed by the atmosphere or other protective coating, it can cause damage to the the atmosphere or other protective coating, it can cause damage to the skin known as skin known as sunburnsunburn or trigger an adaptive change in human or trigger an adaptive change in human skin pigmentationskin pigmentation..

The sunlight that reaches the ground consists of nearly The sunlight that reaches the ground consists of nearly 50% visible light, 45% infrared radiation, and smaller 50% visible light, 45% infrared radiation, and smaller amounts of ultraviolet light and other forms of amounts of ultraviolet light and other forms of electromagnetic radiation.electromagnetic radiation.

This radiation can be converted either into: thermal energy This radiation can be converted either into: thermal energy or into electrical energy.or into electrical energy.

Two main types of devices are used to capture solar Two main types of devices are used to capture solar energy and convert it into thermal energy:energy and convert it into thermal energy:

Flat-plate collectors and Concentrating collectors.Flat-plate collectors and Concentrating collectors. The flat plate collectors are used for hot water heating and The flat plate collectors are used for hot water heating and

house heating.house heating. Concentrating collectors are used when higher Concentrating collectors are used when higher

temperatures are needed. That is, where they reflect and temperatures are needed. That is, where they reflect and concentrate sunlight from a wide area.concentrate sunlight from a wide area.

Solar energy can be converted to Solar energy can be converted to electricity using photovoltaic cells/ solar electricity using photovoltaic cells/ solar cells.cells.

This converted energy is used to provide This converted energy is used to provide electricity for watches, calculators and electricity for watches, calculators and cameras.cameras.

Unfortunately, though solar energy is free, Unfortunately, though solar energy is free, the high cost of its collection, conversion the high cost of its collection, conversion and storage has limited its exploitation.and storage has limited its exploitation.

GENERATION OF SOLAR GENERATION OF SOLAR POWERPOWER

Solar powerSolar power is the is the conversion of conversion of sunlightsunlight into into electricityelectricity, either , either directly using directly using photovoltaicsphotovoltaics (PV), or (PV), or indirectly using indirectly using concentrated solar powerconcentrated solar power (CSP). (CSP).

Photovoltaics converts Photovoltaics converts light into electric current light into electric current using the using the photoelectric effectphotoelectric effect..

Energy storage methods Energy storage methods

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

SOLAR CELLSOLAR CELL

A A solar cellsolar cell (also called (also called photovoltaic cellphotovoltaic cell or or photoelectric cellphotoelectric cell) is a ) is a solid statesolid state device that device that converts the energy of converts the energy of sunlightsunlight directly into directly into electricityelectricity by the by the photovoltaic effectphotovoltaic effect. Assemblies of . Assemblies of cells are used to make cells are used to make solar modulessolar modules, also known as , also known as solar panelssolar panels. The energy generated from these solar . The energy generated from these solar modules, referred to as modules, referred to as solar powersolar power, is an example of , is an example of solar energysolar energy..

Cells are described as Cells are described as photovoltaic cellsphotovoltaic cells when the when the light source is not necessarily sunlight. These are light source is not necessarily sunlight. These are used for detecting light or other used for detecting light or other electromagnetic radiationelectromagnetic radiation near the visible range, for near the visible range, for example example infrared detectorsinfrared detectors, or measurement of light , or measurement of light intensity.intensity.

SOLAR CELLSOLAR CELL

Solar modules/panels

A basic structure of a typical solar cell

Solar technologies are broadly characterized as either Solar technologies are broadly characterized as either passive solarpassive solar or or active solaractive solar depending on the way depending on the way they capture, convert and distribute solar energy. they capture, convert and distribute solar energy.

Active solar techniques include the use of Active solar techniques include the use of photovoltaic panels and photovoltaic panels and solar thermalsolar thermal collectors to collectors to harness the energy.harness the energy.

Passive solar techniques include orienting a building Passive solar techniques include orienting a building to the Sun, selecting materials with favorable to the Sun, selecting materials with favorable thermal massthermal mass or light dispersing properties, and or light dispersing properties, and designing spaces that designing spaces that naturally circulate airnaturally circulate air..

Active solar technologies increase the supply of Active solar technologies increase the supply of energy and are considered energy and are considered supply sidesupply side technologies, technologies, while passive solar technologies reduce the need for while passive solar technologies reduce the need for alternate resources and are generally considered alternate resources and are generally considered demand side technologies.demand side technologies.

APPLICATIONS OF SOLAR APPLICATIONS OF SOLAR ENERGYENERGY

A partial list of solar applications includes A partial list of solar applications includes space heating and cooling through space heating and cooling through solar architecturesolar architecture, , potable waterpotable water via via distillationdistillation and and disinfectiondisinfection, , daylightingdaylighting, , solar hot watersolar hot water, , solar cookingsolar cooking, and high temperature process , and high temperature process heat for industrial purposes.heat for industrial purposes.

To harvest the solar energy, the most common To harvest the solar energy, the most common way is to use way is to use solar panelssolar panels..

AgricultureAgriculture and and horticulturehorticulture AgricultureAgriculture and and horticulturehorticulture seek to optimize seek to optimize

the capture of solar energy in order to optimize the capture of solar energy in order to optimize the productivity of plants. the productivity of plants.

Applications of solar energy in agriculture Applications of solar energy in agriculture aside from growing crops include pumping aside from growing crops include pumping water, drying crops, brooding chicks and water, drying crops, brooding chicks and drying chicken manuredrying chicken manure

More recently the technology has been More recently the technology has been embraced by vinters, who use the energy embraced by vinters, who use the energy generated by solar panels to power grape generated by solar panels to power grape presses.presses.

GreenhousesGreenhouses convert solar light to heat, convert solar light to heat, enabling year-round production and the growth enabling year-round production and the growth (in enclosed environments) of specialty crops (in enclosed environments) of specialty crops and other plants not naturally suited to the and other plants not naturally suited to the local climate. local climate.

Solar lightingSolar lighting DaylightingDaylighting systems collect and systems collect and

distribute sunlight to provide distribute sunlight to provide interior illumination. interior illumination.

Hybrid solar lightingHybrid solar lighting is an is an active solaractive solar method of providing method of providing interior illumination. interior illumination.

Solar thermal technologies can Solar thermal technologies can be used for water heating, space be used for water heating, space heating, space cooling and heating, space cooling and process heat generationprocess heat generation

Solar hot water systems use Solar hot water systems use sunlight to heat water.sunlight to heat water.

Water treatmentWater treatment Solar distillation can be used to Solar distillation can be used to

make make salinesaline or or brackish waterbrackish water potablepotable

Solar water Solar water disinfectiondisinfection (SODIS) (SODIS) involves exposing water-filled involves exposing water-filled plastic plastic polyethylene terephthalatepolyethylene terephthalate (PET) bottles to sunlight for (PET) bottles to sunlight for several hoursseveral hours

It is recommended by the It is recommended by the World Health OrganizationWorld Health Organization as a as a viable method for household viable method for household water treatment and safe storagewater treatment and safe storage

Solar energy may be used in a Solar energy may be used in a water stabilisation pond to treat water stabilisation pond to treat waste waterwaste water without chemicals or without chemicals or electricity. electricity.

Solar water heater

CookingCooking Solar cookers use sunlight for Solar cookers use sunlight for

cooking, drying and cooking, drying and pasteurizationpasteurization. . They can be grouped into three broad They can be grouped into three broad categories: box cookers, panel categories: box cookers, panel cookers and reflector cookerscookers and reflector cookers

A basic box cooker consists of an A basic box cooker consists of an insulated container with a transparent insulated container with a transparent lid. lid.

Panel cookers use a reflective panel Panel cookers use a reflective panel to direct sunlight onto an insulated to direct sunlight onto an insulated container and reach temperatures container and reach temperatures comparable to box cookers. comparable to box cookers.

Reflector cookers use various Reflector cookers use various concentrating geometries (dish, concentrating geometries (dish, trough, Fresnel mirrors) to focus trough, Fresnel mirrors) to focus light on a cooking container. light on a cooking container.

The Solar Bowl in Auroville, India,

Process heatProcess heat Solar concentrating Solar concentrating

technologies such as technologies such as parabolic dish, trough and parabolic dish, trough and Scheffler reflectors can Scheffler reflectors can provide process heat for provide process heat for commercial and industrial commercial and industrial applications. applications.

Evaporation ponds are Evaporation ponds are shallow pools that shallow pools that concentrate dissolved solids concentrate dissolved solids through through evaporationevaporation. .

Clothes linesClothes lines, , clotheshorsesclotheshorses, , and clothes racks dry clothes and clothes racks dry clothes through evaporation by wind through evaporation by wind and sunlight without and sunlight without consuming electricity or gas. consuming electricity or gas.

STEP parabolic dishes used for steam production and electrical generation.

Electrical generationElectrical generation(solar power)(solar power)

Solar power is the Solar power is the conversion of sunlight into conversion of sunlight into electricityelectricity, either directly , either directly using using photovoltaicsphotovoltaics (PV), (PV), or indirectly using or indirectly using concentrated solar powerconcentrated solar power (CSP). CSP systems use (CSP). CSP systems use lenses or mirrors and lenses or mirrors and tracking systems to focus a tracking systems to focus a large area of sunlight into a large area of sunlight into a small beam. PV converts small beam. PV converts light into electric current light into electric current using the using the photoelectric effectphotoelectric effect..

Experimental solar powerExperimental solar power

A A solar pondsolar pond is a pool of salt water (usually 1–2 is a pool of salt water (usually 1–2 mm deep) that collects and stores solar energy. deep) that collects and stores solar energy.

The pond consisted of layers of water that The pond consisted of layers of water that successively increased from a weak salt solution at successively increased from a weak salt solution at the top to a the top to a high salthigh salt solution at the bottom. solution at the bottom.

This solar pond was capable of producing This solar pond was capable of producing temperatures of 90 °C in its bottom layer and had an temperatures of 90 °C in its bottom layer and had an estimated solar-to-electric efficiency of two percent.estimated solar-to-electric efficiency of two percent.

ThermoelectricThermoelectric, or "thermovoltaic" devices convert a , or "thermovoltaic" devices convert a temperature difference between dissimilar materials temperature difference between dissimilar materials into an electric current. into an electric current.

Solar chemicalSolar chemical Solar chemical processes use solar energy to drive Solar chemical processes use solar energy to drive

chemical reactions. These processes offset energy that chemical reactions. These processes offset energy that would otherwise come from an alternate source and can would otherwise come from an alternate source and can convert solar energy into storable and transportable fuels. convert solar energy into storable and transportable fuels. Solar induced chemical reactions can be divided into Solar induced chemical reactions can be divided into thermochemical or thermochemical or photochemicalphotochemical

Hydrogen productionHydrogen production technologies been a significant area technologies been a significant area of solar chemical research since the 1970s. of solar chemical research since the 1970s.

Another approach uses the heat from solar concentrators Another approach uses the heat from solar concentrators to drive the to drive the steam reformationsteam reformation of natural gas thereby of natural gas thereby increasing the overall hydrogen yield compared to increasing the overall hydrogen yield compared to conventional reforming methodsconventional reforming methods

Thermochemical cycles characterized by the Thermochemical cycles characterized by the decomposition and regeneration of reactants present decomposition and regeneration of reactants present another avenue for hydrogen production. another avenue for hydrogen production.

Solar vehiclesSolar vehicles Some vehicles use solar Some vehicles use solar

panels for auxiliary power, panels for auxiliary power, such as for air such as for air conditioning, to keep the conditioning, to keep the interior cool, thus reducing interior cool, thus reducing fuel consumptionfuel consumption

A A solar balloonsolar balloon is a black is a black balloon that is filled with balloon that is filled with ordinary air. ordinary air.

Solar sailsSolar sails are a proposed are a proposed form of spacecraft form of spacecraft propulsion using large propulsion using large membrane mirrors to membrane mirrors to exploit radiation pressure exploit radiation pressure from the Sun. from the Sun.

SOLAR ENERGY PROSSOLAR ENERGY PROS Solar panels give off no pollutionSolar panels give off no pollution Solar energy produces electricity very quietly.Solar energy produces electricity very quietly. It has the ability to harness electricity in remote It has the ability to harness electricity in remote

locations that are not linked to a national grid. locations that are not linked to a national grid. Very efficient in large areas of the globe.Very efficient in large areas of the globe. Solar panels can be installed on top of many rooftopsSolar panels can be installed on top of many rooftops It is affordable in the long run. It is affordable in the long run. The use of solar energy to produce electricity allows The use of solar energy to produce electricity allows

the user to become less dependent on the worlds fossil the user to become less dependent on the worlds fossil fuel supplies.fuel supplies.

SOLAR ENERGY CONSSOLAR ENERGY CONS

The major con of solar energy is the initial cost of The major con of solar energy is the initial cost of solar cells. solar cells.

Solar energy is only able to generate electricity during Solar energy is only able to generate electricity during daylight hours. This means for around half of each daylight hours. This means for around half of each day, solar panels are not producing energy for your day, solar panels are not producing energy for your home.home.

The weather can affect the efficiency of solar cells.The weather can affect the efficiency of solar cells. Pollution can be a con of solar energy, as pollution Pollution can be a con of solar energy, as pollution

levels can affect a solar cells efficiency, this would be levels can affect a solar cells efficiency, this would be a major con for businesses or industry wishing to a major con for businesses or industry wishing to install solar panels in heavily polluted areas, such as install solar panels in heavily polluted areas, such as cities.cities.

Environmental Effects of Solar Environmental Effects of Solar EnergyEnergy

Carbon EmissionsCarbon Emissions Renewable EnergyRenewable Energy Abundant ComponentsAbundant Components CadmiumCadmium Space ConsiderationsSpace Considerations

MEDICAL USES OF SOLAR MEDICAL USES OF SOLAR ENERGYENERGY

These include, disinfection and sterilization without the use of chemicals. Ultraviolet light is also used to destroy bacteria and viruses.

• It stimulates the immune system and has shown good results in killing blood borne pathogens.

• Some microorganisms destroyed by ultraviolet light are bacillus anthracis, salmonella or food poisoning, shigella dysentariae or dysentery, bacteriophage or E. coli, hepatitis and influenza.

Ultraviolet light can be combined with other Ultraviolet light can be combined with other therapies.therapies.

Some kinds of skin conditions can improve with the Some kinds of skin conditions can improve with the exposure of ultraviolet light.exposure of ultraviolet light.

Solar Energy Health Effects on Solar Energy Health Effects on HumansHumans

These are:These are: Electromagnetic Radiation From Solar Electromagnetic Radiation From Solar

PanelsPanels Silicon Dust from Solar PanelsSilicon Dust from Solar Panels Exposure to Electrical and Chemical Exposure to Electrical and Chemical

Components of Solar Heat SystemsComponents of Solar Heat Systems The Future of Solar EnergyThe Future of Solar Energy

The body produces The body produces vitamin Dvitamin D from sunlight from sunlight (specifically from the UVB band of (specifically from the UVB band of ultravioletultraviolet light), and excessive seclusion from the sun light), and excessive seclusion from the sun can lead to deficiency unless adequate can lead to deficiency unless adequate amounts are obtained through diet.amounts are obtained through diet.

On the other hand, excessive sunlight exposure On the other hand, excessive sunlight exposure has been linked to all types of has been linked to all types of skin cancerskin cancer caused by the caused by the ultravioletultraviolet part of radiation from part of radiation from sunlight or sunlampssunlight or sunlamps

A lack of sunlight, on the other hand, is A lack of sunlight, on the other hand, is considered one of the primary causes of considered one of the primary causes of seasonal affective disorderseasonal affective disorder (SAD), a serious (SAD), a serious form of the "winter blues". SAD occurrence is form of the "winter blues". SAD occurrence is more prevalent in locations further from the more prevalent in locations further from the tropics, and most of the treatments (other than tropics, and most of the treatments (other than prescription drugs) involve prescription drugs) involve light therapylight therapy

A recent study indicates that more exposure to A recent study indicates that more exposure to sunshine early in a person’s life relates to less sunshine early in a person’s life relates to less risk from risk from multiple sclerosismultiple sclerosis (MS) later in life (MS) later in life

SOLAR ENERGY AND GUYANASOLAR ENERGY AND GUYANA

Solar energy is primarily being installed in the Solar energy is primarily being installed in the hinterland/remote areas of the country. Currently under the hinterland/remote areas of the country. Currently under the Unserved Areas Electrification Programme, a number of Unserved Areas Electrification Programme, a number of communities have received solar photovoltaic’s home communities have received solar photovoltaic’s home systems. systems.

Solar power will provide lights, entertainment & emergency Solar power will provide lights, entertainment & emergency communication for 100 persons in Wayling.communication for 100 persons in Wayling.

““Solar energy systems have been tested/validated in several Solar energy systems have been tested/validated in several hinterland communities. Combined with appropriate learning hinterland communities. Combined with appropriate learning tools these small systems can revolutionize Guyana’s rural tools these small systems can revolutionize Guyana’s rural educational system.” educational system.” - - Edward Jarvis, Field Coordinator, Ministry of EducationEdward Jarvis, Field Coordinator, Ministry of Education

REFERENCEREFERENCE Ref: Solar energyRef: Solar energy From Wikipedia, the free encyclopedia.This page was last modified on 7 March From Wikipedia, the free encyclopedia.This page was last modified on 7 March

2011 at 12:56.Retrieved on 2011-03-072011 at 12:56.Retrieved on 2011-03-07http://en.wikipedia.org/wiki/Solar_energyhttp://en.wikipedia.org/wiki/Solar_energy Duncan Tom, Onac Deniz- Physics for the Caribbean: John Murray Ltd.: London: Duncan Tom, Onac Deniz- Physics for the Caribbean: John Murray Ltd.: London:

19851985 Lambert norman, Samuel A. Tricia- Heinemann Physics for CXC: Heinemann Lambert norman, Samuel A. Tricia- Heinemann Physics for CXC: Heinemann

Educational Publishers: Oxford:2000.Educational Publishers: Oxford:2000. Rianne Hill Soriano, eHow Contributor Rianne Hill Soriano, eHow Contributor Solar Energy Health Effects on Solar Energy Health Effects on

Humans,Humans,updated: April 02, 2010retrieved on 18-03-2011<updated: April 02, 2010retrieved on 18-03-2011<Solar Energy Health Effects on Humans | eHow.comSolar Energy Health Effects on Humans | eHow.com http://www.ehow.com/list_6155201_solar-energy-health-effects-humans.html#ixzz1Gov4MiqRhttp://www.ehow.com/list_6155201_solar-energy-health-effects-humans.html#ixzz1Gov4MiqR>>

Sherry Barnhart, eHow Contributor ,Sherry Barnhart, eHow Contributor ,Medical Use of Ultraviolet Lights | eHow.comMedical Use of Ultraviolet Lights | eHow.com http://www.ehow.com/about_5185794_medical-use-ultraviolet-lights.html#ixzz1Goy9gjnghttp://www.ehow.com/about_5185794_medical-use-ultraviolet-lights.html#ixzz1Goy9gjng