Alternative Energy Sources

1. Alternative Energy Sources Julio Contreras, Julian Contreras, Ilian Meza and Kevin Pascua

2. An electric generator is a device that converts mechanical energy to electrical energy. •A generator forces electrons in the windings to flow through the external electrical circuit. •The source of mechanical energy may be a turbine steam engine, water falling through a turbine or, a wind turbine, compressed air or any other source of mechanical energy. http://science.howstuffworks.com/electricity2.htm

3. Rotor: The rotating part of an electrical machine • Stator: The stationary part of an electrical machine • Water stores potential energy http://ga.water.usgs.gov/edu/hyhowworks.html

4. Hydroelectric power now supplies about 715,000 megawatts or 19% of world electricity. damsproduce electrical power through the use of gravitational force of falling or flowing water. energysource is normally applied to peak load demand, because it is readily stopped and started The world's largest Dam is the Three Gorges Dam on the third longest river in the world, the Yangtze River. http://www.top-alternative-energy-sources.com/hydroelectric-power.html http://en.wikipedia.org/wiki/Three_Gorges_Dam

5. Pumped storage is a method of keeping water in reserve for peak period power demands Water that has already pumped flowed down, gets pumped back up to a storage pool next to dam This process is done too provide enough energy when customer demand for energy is high, such as during the middle of the day. Thisprocess is usually done at night when energy demand is relatively low

7. PROS • Directly stores water • In case of a drought, the dam will still have a relatively constant supply of water • Controls flooding & provides recreational activities such as boating fishing and swimming, if the lake is not being used for drinking water • Simple design makes for inexpensive repairs and maintenance costs • Produce inexpensive (after completion) and clean power • If needed,can be shut down instantly, where thermal plants take hours, and nuclear plants can take days

8. CONS • Requires flooding of entire valleys and scenic areas • Disrupts natural seasonal changes in he river, and ecosystems can be destroyed • plant decay caused downstream of major dams produces as many greenhouse gasses as more conventional methods of producing electricity • Expensive to build  http://www.ussdams.org/

9. A wind energy system transforms the kinetic energy of the wind into mechanical or electrical energy that can be harnessed for practical use. Wind electric turbines generate electricity for homes and businesses and for sale to utilities. www.awea.org/faq/wwt_basics.htm

10. http://www.e-marine-inc.com/products/images/windmap.gif

11. Pros • One of the cheapest forms of energy available today • Doesn’t release any harmful pollutants or gases as byproducts • Safer and cleaner source of energy than natural gas, coal or oil • Efficient renewable energy • A never ending resource, therefore power cuts and power failures are almost non-existent in areas that rely upon wind power to generate electricity • Cons • Wind turbines can get damaged or completely destroyed when hit by a heavy storm or a severe lightning • Helps to solve the electricity problems up to a large extent, but it does not eliminate it completely • Doesn’t necessarily flow in the same speed all the time. http://www.awea.org/faq/wwt_basics.html

12. Solar Energy

14. Uses of Solar Energy • Production [of electricity] and heating of water through photovoltaic cells and directly for drying clothes • Also used to heat swimming pools, power cars, attic fans, calculators and other small appliances • produces lighting for indoors or outdoors • cook food • About 30% of our total energy consumption is used to heat water

15. Solar Energy Forms

16. Photovoltaic (PV) solar cells • directly convert sunlight into electricity • are combined into modules called arrays, and the number of arrays used determines the amount of electricity produced • simplest cells are used to operate wristwatches and calculators; more complicated systems are used to light houses

18. Pros & Cons • No pollution • Able to harness electricity in remote locations that are not linked to a national grid Ex. in space, satellites are powered by high efficiency solar cells • The installation of solar panels in remote locations is usually much more cost effective than laying the required high voltage wires • Can be very efficient in a large area of the globe, and new technologies allow for a more efficient energy production on overcast/dull days • Solar panels can be installed on top of many rooftops, eliminating the problem of finding the required space for solar panel placement • Once installed, they provide a free source of electricity, which will pay off over the coming years • the initial cost of solar cells can be above $1000, and some households may need more than one • for around half of each day, solar panels are not producing energy for your home • weather can affect the efficiency of solar cells • pollution levels can affect a solar cells efficiency, this would be a major con for businesses or industry wishing to install solar panels in heavily polluted areas, such as cities http://www.clean-energy-ideas.com/articles/pros_and_cons_of_solar_energy.html

19. Geothermal Energy

20. What is it? • Geothermal energy is contained in underground reservoirs of steam, hot water, and hot dry rocks • Originates from radioactive decay of minerals, and from solar energy absorbed at the surface

21. Energy Efficiency • The thermal efficiency of geothermal plants is low. • Energy around 10-23% because geothermal fluids do not reach the high temperatures of steam from boilers • Created using Rankine cycle

22. Uses • For bathing since Paleolithic times • Space heating since ancient Roman times • Now more commonly used for electricity

23. Geothermal Map of the U.S www.wikipedia.org

24. Geothermal Hotspots www.wikipedia.org

25. Pros and Cons

26. Comparing