The Power of the SunBy Anna and Gloria

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First Discovery and Use The Greeks and Romans were

probably the first people to discover the power of the sun and put that energy to use.

Edmund Becquerel discovered the photovoltaic effect in 1839 wile experimenting with the electrolytic cell.

Russell Ohl was the first person to find a way to harness the sun’s energy when he invented the solar cell in 1941.

Gerald Pearson, Calvin Fuller and Daryl Chapin worked together to invent the first efficient solar panels.

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When and where is was first used

The sun’s energy was first used in about 400 BC in Greece and Rome.

After Ohl discovered how to harness the sun’s energy through solar cells, satellites in space began to use them to produce electricity.

The efficient solar battery was first used in a telephone carrier system in Americus, Georgia on October 4, 1955

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Why? The Romans and

Greeks developed the use of the sun’s energy to heat buildings and water. The Greeks also used it to grow vegetables in greenhouses.

Solar cells were first used to provide electricity for satellites and when cheaper alternatives were unavailable.

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How? The Greeks and Romans

discovered that by building their houses a certain way would trap the heat inside and making darker colored pots would keep the contents warmer for longer.

Pearson, Fuller and Chapin put several strips of silicon the size of razorblades in the sunlight and captured the free electrons and turned them into an electrical current.

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Diagram- Water

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Diagram- Electricity

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Steps of Solar energy production

The sun hits the solar panels

Solar panels collect energy from the sun

The collected solar energy is sent to the electric panel

The electric panel provides electricity for the building

Excess energy can be sold to the power company

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Current Uses Heat

– Passive: Air is circulated past the solar heat surface and through the building by convection.

– Active: A “collector” absorbs and collects solar radiation. Fans or pumps circulate the heated air.

Electricity– Thermal power plants

Parabolic trough: focuses the sun’s rays on a receiver pipe and moves with the sun as the day progresses

Solar dish: tracks the sun and points straight at it to receive concentrated solar energy

Solar power tower: focuses concentrated solar energy gathered by rotating mirrors on a tower- mounted heat exchanger/ receiver

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Where is it currently used?

Residential and business buildings

Vehicles Roadway signs Heating water Creating portable

water

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Future Plans

Storing excess energy

Creating a miniature “sun” on earth to help power solar cells when the sun is not shining

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Benefits It is renewable, which means it can

never run out. It is environmentally friendly

because solar cells don’t produce pollutants.

Solar cells don’t make noise. It is cheaper than electricity. There is a large variety of solar

panel systems available. Can sell the excess electricity

produced by the solar cells. Government will provide a tax

credit or incentive for purchasing solar energy systems.

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Disadvantages The initial cost of the equipment used to

harness the sun’s energy Large areas are needed for the equipment in

order for the system to be efficient. This is inconvenient for people that live in areas where there is not a lot of space, or where space is expensive, such as inner cities.

Pollution can degrade the efficiency of photovoltaic cells

Solar panels only work when the sun is shining. This means that when it is cloudy or nighttime the solar panels are less effective.

The location of solar panels can affect performance, due to possible obstructions such as buildings or the landscape.

Toxic materials, chemicals, solvents and alcohols that are produced in the process of making PV cells

Large solar thermal power plants harm desert ecosystems if they are not properly managed.

Birds and insects can be killed if they fly into a concentrated beam of sunlight produced by the “solar power tower”

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References• http://ezinearticles.com/?10-Benefits-of-Solar-Energy&id=2154024 http://www.clean-energy-ideas.com/articles/disadvantages_of_solar_e

nergy.html http://www.eia.doe.gov/kids/energy.cfm?page=solar_home-basics http://www.annesley.sa.edu.au/amep/energyconservation_solarenerg

y/history.htm http://inventors.about.com/od/sstartinventions/a/solar_cell.htm http://encyclobeamia.solarbotics.net/articles/photovoltaic.html http://www.articlesbase.com/technology-articles/how-is-solar-energy-u

sed-today-and-what-are-the-plans-for-the-future-1497115.html http://dsc.discovery.com/videos/powering-the-future-clips-solar.html

Picture References http://www.solargain.ca/EAC_solar.html http://www.latrobeschool.com/about/facilities.html http://nobelprize.org/nobel_prizes/physics/laureates/1903/becquerel-bio.html http://www.solarpowerninja.com/solar-power-technology/recreating-the-sun-to-

harness-solar-power-74901/ http://portal.unesco.org/ci/en/ev.php-URL_ID=11543&URL_DO=DO_TOPIC&U

RL_SECTION=201.html http://www.powertripenergy.com/pv_hist.htm http://www.norcalblogs.com/watts/2006/12/post_1.html http://inhabitat.com/wp-content/uploads/sunpower_main.jpg http://www.trec-uk.org.uk/press/brussels/prince_hassan_presentation.html http://www.huffingtonpost.com/alanna-zabel/the-hybrid-hype_b_618875.html http://www.scientificamerican.com/article.cfm?id=how-to-use-solar-energy-at-

night http://www.markburrier.com/blog/2009/03/ominous-clouds/ http://green-energy-center.blogspot.com/2008/08/grants-for-clean-energy-

business.html