Renewable Energy Sources: Solar and Geothermal Energy, Study notes of Earth science

Download Renewable Energy Sources: Solar and Geothermal Energy and more Study notes Earth science in PDF only on Docsity! Energy resources are essential for any society, be it one dependent on subsistence farming or an industrialized country. There are many different sources of energy, some well-known Renewable Energy Resources - referred to as clean energy , comes from natural sources or processes that are constantly replenished. Example of is sunlight, wind, geothermal energy Solar Energy – Type of energy that generated by the sun The sun in our solar system is the main source of energy for every living matter in the planet. Plants can process food for animals and course for us human beings. It can be managed with the aid of solar panels to be collected and convert into useful electrical energy. Actually, it is free and inexhaustible. How Solar Panel Works? Solar power works by converting light from the sun into electricity Useful at home How would it be done? Installing solar panels on your roof which generate DC (Direct Current) electricity Advantages: 1. Solar power is pollution free and causes no greenhouse gases to be emitted after installation 2. Reduced dependence on foreign oil and fossil fuels 3. Renewable clean power that is available every day of the year, even cloudy days produce some power 4. Return on investment unlike paying for utility bills 5. Virtually no maintenance as solar panels last over 30 years 6. Creates jobs by employing solar panel manufacturers, solar installers, etc. and in turn helps the economy 7. Excess power can be sold back to the power company if grid intertied 8. Ability to live grid free if all power generated provides enough for the home / building 9. Can be installed virtually anywhere; in a field to on a building 10. Use batteries to store extra power for use at night 11. Solar can be used to heat water, power homes and building, even power cars 12. Safer than traditional electric current 13. Efficiency is always improving so the same size solar that is available today will become more efficient tomorrow 14. Aesthetics are improving making the solar more versatile compared to older models; i.e. printing, flexible, solar shingles, etc. 15. Federal grants, tax incentives, and rebate programs are available to help with initial costs 16. No trenching is needed since the solar can be close to or at the place of installation Disadvantages: 1. High initial costs for material and installation (however, with the reduction in cost of solar over the last 10 years, solar is becoming more cost feasible every day) 2. Needs lots of space as efficiency is not 100% yet 3. No solar power at night so there is a need for a large battery bank 4. Some people think they are ugly (I am definitely not one of those!) 5. Devices that run on DC power directly are more expensive 6. Depending on geographical location the size of the solar panels vary for the same power generation 7. Cloudy days do not produce as much energy 8. Solar panels are not being massed produced due to lack of material and technology to lower the cost enough to be more affordable (this is starting to change) 9. Solar powered cars do not have the same speeds and power as typical gas powered cars (this too is starting to change) 10. Lower solar production in the winter months Geothermal Energy - Geothermal energy has been used for thousands of years in some countries for cooking and heating. It is simply power derived from the Earth’s internal heat. This thermal energy is contained in the rock and fluids beneath Earth’s crust. It can be found from shallow ground to several miles below the surface, and even farther down to the extremely hot molten rock called magma. Types of Geothermal Energy 1. Liquid Dominated Geothermal Plants 2.Vapor Dominated Geothermal Plants 3. Binary Cycle Plants 1. Liquid Dominated Geothermal Plants In liquid dominated plants, geothermal plants are built upon liquid reservoirs within the earth’s surface. This liquid is sent through one or more separators in order to lower the pressure of the water, creating steam. This steam then propels a turbine generator causing it to produce electricity. This steam is then condensed back into a liquid and placed back into the liquid reservoir it originated from. This type of geothermal plant is very common and provides a sustainable, reusable form of energy. Such power plants operate using water reservoirs with temperatures greater than 360 degrees Fahrenheit. Liquid dominated reservoirs are more common than others, causing them to produce more electricity and power more stations. These reservoirs are found in specific locations including rift zones, mantle hot spots, and near new volcanoes in the Pacific Ocean. The largest liquid- dominated system in the world is found at Cerro Prieto. 2.Vapor Dominated Geothermal Plants Steam reservoirs are very rare but are an incredibly efficient sustainable electricity source. The Geysers in California is the most prominent dry steam reservoir. A dry steam plant works in a similar fashion to a Liquid Dominated Geothermal Plant. Steam is obtained by drilling between seven to ten thousand feet deep into the earth’s crust. The steam obtained is piped directly into a turbine generator, producing electricity. The steam is then condensed and placed back into the steam reservoir, providing a reusable energy source. Vapor Dominated Plants, also referred to as dry-steam power plants, are so rare that only two locations exist in the United States. These include The Geysers in California, previously mentioned above, and the famous dry steam reservoir held at Yellowstone National Park. The most prominent international dry steam power plant exists in Larderello, Italy. In Larderello, hot granite on the earth’s surface creates boiling water and hot steam under the earth’s surface. The geothermal plant in Larderello is able to convert this dry