INTERACTIVE WEBSITE ON BIOFUEL
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Tuesday, March 17, 2009
Renewable sources of energy refer to energy that is derived from natural processes that are replenished constantly. Some renewable resources include solar energy, biomass, hydroelectricity and others.
Hydroelectricity  Source: National Renewable Energy Laboratory, Photographic Information Exchange.http://www.eia.doe.gov/cneaf/solar.renewables/page/hydroelec/hydroelec.html Hydroelectricity is electricity driven by moving water. More than half of the worlds’s hydropower is produced by Brazil, Canada, China, Russia and the United States currently. Advantages A lot of energy can be produced with hydroelectricity. No fuel is required in the process of producing the hydroelectricity thus it can reduce the pollution evolved from the burning or extraction of fuels. Disadvantages A lot of space is required for building the reservoirs and dams. It is also very expensive to set up the entire project. When dams are built, these can also affect the ecosystem as fishes cannot migrate to the different places. Solar  Source: http://www.vias.org/kas/en/solar_energy.htmlSolar energy is obtained when sunlight is turned into electricity by the solar cells. Currently, solar energy is being used in the areas of agriculture, horticulture, greenhouses and disinfection of water. Advantages There is unlimited supply of sun’s energy at no cost. It would not cause pollution. Disadvantages The solar cells would not be able to generate electricity at night or in places where there are a lot of clouds. Moreover, it can be quite expensive to build the solar panels and cells. Biomass  Biomass was human’s first source of energy. It is a renewable energy resource derived from organic matter like dead trees, branches, leftover crops, and livestock manure. When burnt, the chemical energy in biomass is used to provide heat to industries and homes or to heat up water to produce steam to generate electricity. Biomass can also be made into bio-diesels. Advantages Plants and livestock manure are by nature carbon neutral and renewable, thus when burning these biomass fuels, the carbon dioxide levels in the atmosphere are reduced. Disadvantages The amount of land is limited. As such there may be a competition between the use of biomass to produce fuels and the usage of biomass as fertilizers to increase the crops productions. Geothermal  The Earth’s interior contains very huge amounts of heat, which are generated when the radioactive elements decay. This Earth’s heat can also be used to warm houses and generate electricity. Countries which use geothermal energy will include Iceland, Kenya, Costa Rica, El Salvador and the Philippines. Advantages Geothermal resources require no fuel so this will cause lesser pollution to the atmosphere. Residual heat left behind from after generation can be used for domestic heating or for industrial processes thus there is minimal wastage. Disadvantages This geothermal resource can be used in specific places such as those with abundant hot springs. It can also be costly to build the geothermal system because of the area geological settings. Carbon dioxide may leak from the geothermal fields or the when water brings the heat to the surface, they may carry toxic compounds and all these will cause contamination problems. Monday, March 16, 2009
Comparing Renewables and Fossil Fuel
Comparing between Renewables and Fossil Fuels
Renewables 2. “Clean energies” because they do not release gases that pollute the environment 3. Smaller carbon footprint because of lower GHG* emissions
Fossil Fuels 2. “Dirty fuels” because they releases harmful gases into the environment during burning 3. Larger carbon footprint because of higher GHG* emissions |
