The document summarizes the pros and cons of various renewable energy sources including solar, wind, hydro, and biomass energy. It discusses that while solar and wind are free sources of energy, they have limitations based on weather and location. Hydroelectric power is inexpensive once dams are built but can damage ecosystems. Biomass energy utilizes waste but production and storage of raw materials is expensive. The document also provides examples of energy innovations and news articles on renewable energy projects.

1. -Solar -Wind -Hydro -Biomass Renewable energies Kara, Tian, Jake, Jack and Albert’s presentation

2. Cons of Solar Energy Currently, prices of highly efficient solar cells can be above $1000, and some households may need more than one. This makes the initial installation of solar panels very costly. Solar energy is only able to generate electricity during daylight hours. This means for around half of each day, The weather can affect the efficiency of solar cells. Pollution can be a con of solar energy, as 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.

3. Pros of Solar Energy Solar panels give off no pollution, the only pollution produced as a result of solar panels is the manufacturing of these devices in factories, transportation of the goods, and installation. The production of energy from the use of fossil and some renewable fuels (e.g. wind turbines) can be noisy, yet solar energy produces electricity very quietly. Solar energy has the ability to harness electricity in remote locations that are not linked to a national grid. An example of this is in space, where 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. Solar energy 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, which eliminates the problem of finding the required space for solar panel placement. Although the initial investment of solar cells may be high, once installed, they provide a free source of electricity, which will pay off over the coming years. The use of solar energy to produce electricity allows the user to become less dependent on the worlds fossil fuel supplies.

4. The use of wind turbines does not generate pollution or radioactive waste like most other forms of electricity generation do. Their construction and installation has less environmental impact. Wind power may be used to provide electricity to individual homes or other facilities on a self-reliant basis, with no need for fuel or other materials to be supplied. If a natural disaster severs power lines, residents with windmills will not lose their supply of electricity. Wind can also generate power for large numbers of people, using larger turbines connected to an electrical grid. This allows individuals to take advantage of some of their benefits without personally owning or maintaining the equipment. Does not consume any non-renewable resources, like coal, natural gas, or oil so it doesn’t promote environmental harm brought about by obtaining these resources. Pros of Wind Energy

5. Some people consider the turbines to have an undesirable appearance, especially when there are very tall units and/or large groups of them. They can be damaged in thunderstorms, partially because of their tall, thin shape. The website of the National Lightning Safety Institute indicates that most damage to wind turbines is caused by lightening. This is more of a problem in warmer parts of the world. The blades of wind turbines can hit birds who attempt to fly between them. However, it should be kept in mind that birds are also affected by the disadvantages of other power generation methods, especially pollution. Some turbines produce noise but varies from one turbine to the next, and is more likely to happen when the wind speed is low. Cons of Wind Energy

6. Pros of Hydro Power Dams can store rain water or water directly from the river itself. Then, in case of a drought, the dam will still have a relatively constant supply of water. Simple design makes for inexpensive repairs and maintenance costs. Produce inexpensive and clean power. Renewable energy source, because the water is not destroyed by passing through the dam. If needed, dams can be shut down instantly, where thermal plants take hours, and nuclear plants can take days. There is always enough water and will never run out.

7. Cons of Hydro Power Hydroelectric power production require flooding of entire valleys and scenic areas. Disrupts natural seasonal changes in the river, and ecosystems can be destroyed. Ends flooding that help to clean out the silt in rivers, causing them to clog. Studies show that the plant decay caused downstream of major dams produces as many greenhouse gasses as more conventional methods of producing electricity. Dams are expensive to build, and due to drought may become useless, or produce much less power than originally planned. Dams can break in a massive flash flood.

8. Pros of Biomass Energy Heat and electricity are generated during biomass energy production. There is plethora of organic waste and agricultural waste generated everyday. Biomass is produced from these wastes, which makes biomass an easily available resource. It helps in solid waste management by keeping us pollution free. Burning of biological wastes everyday, cuts down the levels of expulsion of carbon into the atmosphere. Thus, it maintains an ecological balance of carbon present in the environment. Biomass briquettes are the substances which produce electricity. The electricity generated by the briquettes is much cleaner than that obtained from fossil fuels. It does not emit any greenhouse gases. Biomass energy is very cost effective. Generally, the energy is generated and supplied in the same area due to which installation of large pipelines is not required.

9. Cons of Biomass Energy Some of the gases like carbon-dioxide, methane and nitrous oxide are emitted into the atmosphere during biomass production which may damage the ozone layer. It may contribute to global warming. The process of extraction of biomass is very expensive. The accumulation, harvesting and storage of raw biomass materials is quite expensive compared to that of fossil fuels. The set up of a biomass power plant requires huge space and the recycling of wastes requires a large amount of water. Ethanol is also produced during the process which may increase the levels of nitrogen oxide in the atmosphere.

10. Comparison s

11. Solar Sunlight is free when available Costs are dropping. Limited to southern areas of U.S. and other sunny areas throughout the world (demand can be highest when least available, e.g. winter solar heating) Does require special materials for mirrors/panels that can affect environment Current technology requires large amounts of land for small amounts of energy generation

12. Wind is free if available. As it turns out, the US has many areas available. Good source for periodic water pumping demands of farms as used earlier in 1900's Generation and maintenance costs have decreased significantly. Wind is proving to be a reasonable cost renewable source. Well suited to rural areas. Examples include Mid-Columbia areas of Oregon and Washington, western Minnesota, Atlantic Ocean off Cape Cod. Need 3x the amount of installed generation to meet demand Limited to windy areas. Limited to small generator size; need many towers. Highly climate dependent - wind can damage equipment during windstorms or not turn during still summer days. May affect endangered birds, however tower design can reduce impact.. Wind

13. Very inexpensive once dam is built Government has invested heavily in building dams, particularly in the Western U.S. Very limited source since depends on water elevation Many dams available are currently exist (not much of a future source[depends on country]) Dam collapse usually leads to loss of life Dams have affected fish (e.g. salmon runs) Environmental damage for areas flooded (backed up) and downstream Hydroelectric

14. Biodiesel Biodiesel is less costly to deploy and transport Using less fuel to earn more oil. Ratio 1:12.5, 1:16.5

15. Inventions in Energy Conservation

16. Solar The Juice Bag Solarjo Power Purse SeV Solar Panel Jacket

17. Solar Powered Contact Lenses Solar Panels Solar Powered Ships

18. Solar powered cars of the future Solar Powered Calculator

19. Wind Tree-Hugging Wind Turbine Wind Turbines

20. Wind Powered Generator for your home Wind Powered Car

21. Hydro Water powered Car Water Powered Clock Water powered jetpack Hydrogen run car

22. Biomass Biomass Run Car

23. How do they work?

24. Solar thermal: The most common solar concentrators is parabolic troughs —long, curved mirrors that concentrate sunlight on a liquid inside a tube that runs parallel to the mirror. The liquid, at about 300 degrees Celsius, runs to a central collector, where it produces steam that drives an electric turbine.

25. Photovoltaics In 1839, French scientist Edmund Becquerel discovered that certain materials would give off a spark of electricity when struck with sunlight. This photoelectric effect was used in primitive solar cells made of selenium in the late 1800s. In the 1950s, scientists at Bell Labs revisited the technology and, using silicon, produced solar cells that could convert four percent of the energy in sunlight directly to electricity. Within a few years, these photovoltaic (PV) cells were powering spaceships and satellites. The most important components of a PV cell are two layers of semiconductor material generally composed of silicon crystals.

26. Wind energy system

27. Typical hydroelectric powerplant Hydroelectric energy is produced by the force of falling water. The capacity to produce this energy is dependent on both the available flow and the height from which it falls. Building up behind a high dam, water accumulates potential energy. This is transformed into mechanical energy when the water rushes down the sluice and strikes the rotary blades of turbine. The turbine's rotation spins electromagnets which generate current in stationary coils of wire. Finally, the current is put through a transformer where the voltage is increased for long distance transmission over power lines. (Source: Environment Canada )

28. News Time!

29. A poll of North Carolina adults shows most support the construction of wind and solar projects in the state but aren't thrilled about using wood or leaves to generate energy. The Elon University Poll released on Monday calculated support for wind energy facilities in the mountains or the coast near 80 percent among 508 adults . N.C. poll shows support for solar energy

30. As if creating the biggest wind turbine in the world was not enough, it also floats. Current plans for the world’s largest wind turbine have the machine standing 533 feet tall. The proposed rotor diameter of this machine is 475 feet. A single floating turbine will be able to generate 10-megawatts to power more than 2,000 homes Sway (Norwegian Company carrying out this plan) plans on installing the device in 2011. The prototype of this machine will cost an estimated $67.5 million dollars. Norwegian Company Develops World’s Largest Wind Turbine

31. Off the coast of Orkney, Scotland, is the Oyster, a white- and yellow-flapped cylinder, 40 feet tall and firmly locked into the ocean's bed. Oyster funnels them into a pipe and carries the power inland to a hydroelectric power generator. The generator has been supplying the United Kingdom's grid with 315 kilowatts of energy at peak power since October. Companies Work to Harness the Power of Waves

32. St. Johns County Recycles Veggie Oil into Biodiesel Fuel St. Johns County started recycling donated waste veggie oil into biodiesel about four years ago. The county program has been so successful, its biodiesel now meets the American Society for the Testing of Materials (ASTM) standard. All of the 313 diesel fuel vehicles in the county, which include ambulances and fire trucks, use the biodiesel fuel which is made at the Public Works facility in St. Augustine. Inman said it costs St. Johns County a $1.98 per gallon to make the biodiesel. That currently saves the county about a buck a gallon over regular diesel.

33. Interesting Facts about Alternative Energy

34. 600 percent: The highest average efficiency of a ground source heat pump in the winter, compared to 250 percent for air-source pumps. 15: Percentage of the average household electricity bill that goes toward lighting alone. 9: Lowest wind speed (in miles per hour) from which it’s efficient to harness wind power. 750: Number of electricity providers that offer a green alternative. 280,475: Number of photovoltaic cells shipped domestically in 2007. 7: Percent of energy that came from renewable sources in 2007. 53: Percent of that renewable energy that was drawn from biomass fuels, the largest supplier, followed by hydroelectric (36%); solar, geothermal, and wind energy all contributed 5% or less.

35. Alternative Energy Rap!

36. Perry, Z. "Advantages and Disadvantages of Wind Power." Hubpages . N.p., 10/09. Web. 2 Mar 2010. http://hubpages.com/hub/advantages-disadvantages-wind . "Pros And Cons Of Solar Energy." Clean Energy Ideas . N.p., 2009. Web. 2 Mar 2010. http://www.clean-energy-ideas.com/articles/pros_and_cons_of_solar_energy.html . Nathan Crawford, Katie Marshall, Ben Pope, And Zeya Wagner, . "Pros and Cons." Water Project . N.p., n.d. Web. 2 Mar 2010. http://drake.marin.k12.ca.us/stuwork/rockwater/Upload%20this%20doc--dams%20and%20hydropower%20report/pros%20and%20cons.html . Ghosh, Suvamita. "Biomass Energy Pros and Cons." Buzzle . Buzzle.com, 2009. Web. 2 Mar 2010. http://www.buzzle.com/articles/biomass-energy-pros-and-cons.html . Copeland, Blythe. "Interesting Facts about Alternative Energy." Planet Green . Planet Green, n.d. Web. 9 Mar 2010. http://planetgreen.discovery.com/go-green/alternative-energy/alternative-energy-numbers.html . Bibliography Jake’s:

37. &quot;Energy Inventions.&quot; Energy Inventions . Web. 8 Mar. 2010. <http://www.alternative-energy-news.info/technology/inventions/>. † InventorSpot . Web. 8 Mar. 2010. <http://inventorspot.com/portable_solar_power>. † NewScientist Tech . Web. 8 Mar. 2010. <http://www.newscientist.com/article/dn16395-invention-treehugging-wind-turbine.html>. † TFOT: The Future Of Things . Web. 8 Mar. 2010. <http://thefutureofthings.com/news/1011/water-powered-car-demonstrated.html>. † Water Powered Car Demonstrated . Web. 8 Mar. 2010. <http://thefutureofthings.com/news/1011/water-powered-car-demonstrated.html>. Bibliography Kira’s:

38. “ Water Science for Schools.” USGS . Web. 8 Mar. 2010. <http://ga.water.usgs.gov/edu/wuhy.html>. “ How Solar Energy Works”. Clean Energy. Web. 8 Mar. 2010. <http://www.ucsusa.org/clean_energy/technology_and_impacts/energy_technologies/how-solar-energy-works.html>. Bibliography Tian’s:

39. http://www.nytimes.com/cwire/2010/03/02/02climatewire-companies-work-to-harness-the-power-of-waves-5213.html http://www.windenergynews.com/content/view/1576/43/ http://www.firstcoastnews.com/news/local/news-article.aspx?storyid=152644&provider=rss http://www.wral.com/news/local/story/7139474/ Bibliography Albert’s:

40. The End. Thank you!