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Alternate Energy. Using Solar Power. Solar Energy. Solar energy: is energy that is created through the use of the sun. Solar energy can be used for heating and electrical production. Using Solar Energy. Just how much Energy do we get from the sun?. About 1300 Watts/Meter 2.
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Alternate Energy Using Solar Power
Solar Energy Solar energy: is energy that is created through the use of the sun. Solar energy can be used for heating and electrical production
Using Solar Energy • Just how much Energy do we get from the sun? • About 1300 Watts/Meter2 Like 13, 100 watt light bulbs, for every square meter!
Enough to power a hair dryer- for every meter2 of the earth OR
So How Do We Use All This Energy? • In what ways, can we make use of solar power? • Heat water- like the roof of a house • Heat air-like a trombe wall( big and dark, “mass”) • Generation stations boil water (think lots of mirrors focused on a single point) • Photovoltaic cells(make electricity)
Active Solar Energy • Active Solar heating systems use fans or pumps to move the heated air or heat absorbing fluid • Collector to absorb and collect solar radiation. Energy storage system (like a water tank). Solar Hot Water Solar Energy Generating Systems (SEGS)
Passive Solar Passive solar is the use of the sun’s energy for the heating of living spaces. Mechanical equipment is notused to move the heated air or liquid Passive space heating is what happens to a car on a hot summer day. South Facing Home Solar Oven
Passive Solar Energy Anasazi Indians used passive heating for hundreds of years
Convection • Convection: is where less dense warm air rises while more dense cooler air moves downward. Example: Hot Air Balloon
Photovoltaic Cells-Where can they be used • Photovoltaic cells(PV) change sunlight into Direct Current(DC) electricity. • Direct Current:Is Electricity that travels in only one direction when connected to a circuit.
Basic Theory of Operation Photon of light Path for E- - - - - N-type - - - - Load - - - - - - - - - - P-type - - - - - - Returning E-
Photovo-what? • Photo·volt·aic cell • Photo- meaning light • Voltaic- volt, a unit of electricity • Cell- a single unit used to create electricity
Semi·Conductor: • Semiconductor materials can both resist or allow the movement of electrons depending on the circumstances.(light/dark) Typically we use Silicon as our primary semiconductor material Where can silicon be found?
Solar Vehicles • Any Vehicle that uses solar power as its energy source.
Solar Cars Electricity from the solar cells is directed to the cars batteries or to the electric motor Electric motor then drives the cars wheels Only about 24% of the sun’s energy can be used by the PV cells =
ElectricMotors A machine that changes electrical energy into mechanical energy.
Advantages of Solar Energy • Solar cars are emission free, and do not continually deplete the Earth's natural resources • Sunlight is free • The energy supply is locally produced
Disadvantages • Solar cars are very expensive • Only 14 - 24% of the Sun’s solar energy is able to be utilized by the PV cells so they must be very large to generate enough energy • Solar cars must be very light and aerodynamic • Designs still need to overcome power to weight problems
History of Photovotaic cells • Russell Ohl- Silicon solar cell • 1941,similar to modern construction,~6% efficient Today- 24% efficiency • Charles Fritts- First Solar Cell • 1883,made of Selenium (semiconductor) and a thin layer of gold,<1% efficient
Solar Energy Weather Issues: • Northeast - only 4 of 10 are sunny :( • Southwest- 8.5 of 10 days are sunny :) • Snow? • Rain? • Clouds? • Seasons?
Installing a Solar Collector: 1. Face the collector south(in northern hemisphere-sun rises in east-travels across southern sky-and sets in west) 2. The sun light rays must hit collector at right angles. Why? 3. Look up your Latitude- 430 Niskayuna 4. Calculate the optimal angle- Latitude +10 = winter angle (12/22) Latitude -10 = summer angle(6/21) Latitude =/- 0 =sping/fall (3/21,9/22) 5. Time of day factor- am sun is low (east ) noon-mid sky (south) pm- sun is low (west)
Basic Electric Terms • Current: Flow of electricity- specifically the flow of electrons, a sub-atomic particle • Polarity: The electrical charge coming from the terminal on a power supply or the charge applied to the terminal of a component. • Conductor: When a material is able to pass electrical current • Insulator: When a material is unable to pass electrical current • Semi-Conductor: A class of materials that can either act like a conductor or an insulator, depending on conditions