Alternative Energy 101

Yuki Bailey

Vivian Eng

Kristen Lee

Chloe Liu

Chemistry Kaya 2:00

OUR PURPOSE…

Enlightenment onSolar Power

Hydroelectric Power

Wind Power

SpecificsMyths

How It Works

Pros/Cons

Solar Power MythsIs 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 energyIntake water flows into dam as kinetic energy, turning turbine which is connected to a generatorThe generator takes energy and produces alternating currents (AC)The transformer collects the AC and converts it to stronger voltage currentsUsed 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 of Wind 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

Energy Costs Comparison Resource Type Average Cost (cents per kWh) Hydroelectric 2-5 Nuclear 3-4 Coal 4-5 Natural gas 4-5 Wind 4-10 Geothermal 5-8 Biomass 8-12 Hydrogen fuel cell 10-15 Solar 15-32 Sources: American Wind Energy Association, Wind Blog, Stanford School of Earth Sciences

IN CONCLUSION…

Alternative energy is flawed…but has a lot of POTENTIAL

Solar Power

= best for personal use

Hydroelectric and Wind Power

=Community use

BibliographySolar Power Resources

http://www.pv.unsw.edu.au/images/future-students/solar-cell_p-n.jpghttp://www.howstuffworks.com/solar-cell.htm/http://www.global-merchants.com/home/solars.htmhttp://www.howstuffworks.com/solar-cell7.htm

Hydroelectric Power Resourceshttp://www1.eere.energy.gov/windandhydro/index.htmlhttp://people.howstuffworks.com/hydropower-plant.htmhttp://science.howstuffworks.com/wind-power.htm

Wind Power Resourceshttp://www.eia.doe.gov/kids/energyfacts/sources/renewable/wind.htmlhttp://www.pacificorp.com/File/File4722.pdf

All Threehttp://www.swarthmore.edu/NatSci/sciproject/windpowertalk.htmlhttp://drake.marin.k12.ca.us/stuwork/rockwater/Upload%20this%20doc--dams%20and%20hydropower%20report/pros%20and%20cons.htmlhttp://egj.lib.uidaho.edu/egi09/youngqu1.html