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Alternative Energy 101. Yuki Bailey Vivian Eng Kristen Lee Chloe Liu Chemistry Kaya 2:00. OUR PURPOSE…. Enlightenment on Solar Power Hydroelectric Power Wind Power Specifics Myths How It Works Pros/Cons. Solar Power Myths. Is Solar energy unlimited? NO!
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Alternative Energy 101 Yuki Bailey Vivian Eng Kristen Lee Chloe Liu Chemistry Kaya 2:00
OUR PURPOSE… • Enlightenment on • Solar Power • Hydroelectric Power • Wind Power • Specifics • Myths • How It Works • Pros/Cons
Solar Power Myths • Is Solar energy unlimited? NO! • Sun will exist for a long time, but at any given place on the Earth’s surface, the amount of sunlight received is limited. • At night or when it is overcast, there may be no daylight at all. • The amount of electricity that can be generated by solar cells is not great compared to the demand. • Solar energy in quantity, requires huge installations. • How do we store significant amounts of electricity when the sun is not available to produce it? • Unknown
How does it work? Photovoltaic cells made out of semi-conductors (often silicon) Sunlight strikes cell then semi conductor material absorbs light energy Allowing the silicon electrons to flow freely PV cells also have at least one electric field that steers the loose electrons into the same direction Metal surfaces located on the top and bottom of PV cells convert this current into usable energy
Pros of Solar Power • A renewable resource as long as there is Sun • No water or air pollution • Can be used for heating and lighting • Heat pools, spas, and water tanks • Low maintenance
Cons of Solar Power • No Sun: NO ENERGY (nighttime and cloudy days) • Solar power stations are $$$ • Can only realistically be used to power transport vehicles by converting light energy into another form of stored energy (battery)
Hydroelectric PowerMyths and Definition • Comes from the potential energy of dammed water driving a water turbine and generator • Clean, no polluting, environmentally friendly: NOT! Because floods the land and displaces wildlife • It is not a renewable energy source if reservoirs are involved (usually)
How does it work? • Water from reservoir is considered to be stored energy • Intake water flows into dam as kinetic energy, turning turbine which is connected to a generator • The generator takes energy and produces alternating currents (AC) • The transformer collects the AC and converts it to stronger voltage currents • Used water comes out back into river
Pros of Hydroelectric Power • Dams can store water directly from the rivers • Provides recreational activities such as fishing, boating, and swimming • Simple design= inexpensive repairs and low maintenance cost • Dams can be shut down instantly if needed • Very few breakdowns
Cons of Hydroelectric Power • Requires flooding • Disrupts natural seasonal changes in the river, ecosystems can be destroyed • Silt that usually flows down to the beaches and estuaries is blocked by the dam • Plant decay caused by downstream of major dams produces green house gases • Expensive to build • If there is a drought, it becomes useless or produces less power
Wind EnergyMyths • Definition: Wind energy propels the blades of wind turbines = energy (by means of electrical generator) • Turbines are noisy: Not! Because noise is = kitchen refrigerator/ moderately quiet room • Turbines are ugly: Not! Beauty is in the eyes of the beholder and careful designing = less visual concerns • Turbines harm wildlife: Not! Because wind energy development’s impact on birds is extremely low compared with other human related activities
How does it work? • Similar to hydropower dams, except using wind kinetic energy to produce currents • Wind moves turbine blades, turning a shaft in the hub that is connected to a generator • Generator changes energy into electricity
Pros ofWind Energy • Produces no pollution that effects the environment (no chemical process take place) • Renewable source= never run out • Farming and grazing can still take place • Can be built off shore
Cons of Wind Energy • Consistent wind is needed for continuous power generation (wind speed decreases= turbine lingers and less energy is generated) • Large wind farms can have a negative effect on scenery • Fact: Today 1.6 million homes are served by wind energy • Goal:2020 =25 million homes served by wind power
IN CONCLUSION… • Alternative energy is flawed…but has a lot of POTENTIAL • Solar Power = best for personal use • Hydroelectric and Wind Power =Community use
Bibliography Solar Power Resources • http://www.pv.unsw.edu.au/images/future-students/solar-cell_p-n.jpg • http://www.howstuffworks.com/solar-cell.htm/ • http://www.global-merchants.com/home/solars.htm • http://www.howstuffworks.com/solar-cell7.htm Hydroelectric Power Resources • http://www1.eere.energy.gov/windandhydro/index.html • http://people.howstuffworks.com/hydropower-plant.htm • http://science.howstuffworks.com/wind-power.htm Wind Power Resources • http://www.eia.doe.gov/kids/energyfacts/sources/renewable/wind.html • http://www.pacificorp.com/File/File4722.pdf All Three • http://www.swarthmore.edu/NatSci/sciproject/windpowertalk.html • http://drake.marin.k12.ca.us/stuwork/rockwater/Upload%20this%20doc--dams%20and%20hydropower%20report/pros%20and%20cons.html • http://egj.lib.uidaho.edu/egi09/youngqu1.html