UNIVERSITY OF TECHNOLOGY FALCUTY OF GEOLOGY & PETROLEUM ENGINEERING ENVIRONMENTAL GEOLOGY REPORT CHAPTER 15 ALTERNATIVE ENERGY Instructor: DR Bui Trong Member list: Huynh Pham Quoc Anh 1410064 Dinh Nguyen Thuy Dung 1410530 Pham Thanh Hoa 1411347 Ngo Kieu Mi 1414914 Vinh INTRODUCTION Alternative energy sources for the future are thus needed, both to supply essential energy and to spare the environment as much disruption as possible And this is true worldwide, for globally, too, fossil fuels are the primary energy source INDEX I Nuclear power 1.Fission IV Wind energy V Biofuels 1.Waste – Derived Fuels 2.Fusion II Energy oceans 2.Alcohol Fuels III Solar energy 3.Solar heating VI Hydropower VII Geothermal Energy 4.Solar electricity Summary i Nuclear power Nuclear power – Fission Fission is the splitting apart of atomic nuclei into smaller ones, with the release of energy Very few isotopes - some 20 out of more than 250 naturally occurring isotopes - can undergo fission spontaneously, and so in nature The fissionable nucleus of most interest in modern nuclear power reactors is the isotope of uranium with 92 protons and 143 neutrons, uranium-235 Nuclear fission and chain reaction involving uranium-235 (schematic) Neutron capture by uranium-235 causes fission into two smaller nuclei plus additional neutron How the nuclear fission occur? Nuclear Fission Diagrams Nuclear power – Fusion Nuclear fusion is the opposite of fission As noted earlier, fusion is the process by which two or more smaller atomic nuclei combine to form a larger one, with an accompanying release of energy It is the process by which the sun generates its vast amounts of energy For technical reasons, fusion of the heavier hydrogen isotopes deuterium and tritium would be easier to achieve on earth Since fusion is a far “cleaner” form of nuclear power than fission, why not use it? • To bring about a fusion reaction, the reacting nuclear must be brought very close together at extremely high temperatures (millions of degrees at least) • The natural tendency of hot gases is to expand, not come together, and no known physical material could withstand such temperatures to contain the reacting nuclei We would have a new sun if we were careless! The Geology Deposits of Uranium Worldwide, 95% of known uranium reserves are found in sedimentary or metasedimentary rocks, distributed mainly in Australia 21%, Kazakhstan 19%, Canada 10%, South Africa 8%, USA 8%, Namibia 7%, Brazil 6%, Russia 4% Advantages and disadvantages of nuclear power Generate a large am Green en ergy Not poll ute Independ e the air nt fuel ount of e ne rgy VS t n a i d a R ns o p a e rw a e l c u n p o l e v De t n a l p r e w o p r a le c u n t n ts Accide s o c n c tio u r t s n o c e g u H ste a w r a Nucle Hydropower is an important renewable energy source in the United States Advantage • No pollutants! • Say no to greenhouse gases • Saving natural resources • A predictable renewable source of energy • Economical advantage • Controllable source of energy • Economical advantage DISADVANTAGE • Emission of methane and carbon dioxide • Disturbance of habitat • Installation costs • Limited use • Divert natural waterway • Effects on agriculture • Fish killing • Breaking of dams Three Gorges Dam Project, Wushan, Yangtze River, China 2002 VII GEOTHERMAL ENERGY The earth contains a great deal of heat, some of it left over fromits early history, some continually generated by decay of radioactive elements in the earth Traditional Geothermal Energy Uses Magma rising into the crust from the mantle brings unusually hot material nearer the surface Heat from the cooling magma heats any ground water circulating nearby the basis for extracting geothermal energy scale Geothermal energy is utilized by tapping circulating warmed ground water The magma-warmed waters may escape at the surface in geysers and hot springs, signalling the existence of the shallow heat source below One of the many thermal features in Yellowstone National Park: Lone Star Geyser Structure is built by deposition of dissolved minerals • High heat flow signals unusually high temperatures at shallow depths • High heat flow and recent (or even current) magmatic are most often associated with plate boundaries most areas in which geothermal energy is being tapped extensively are along or near plate boundaries Geothermal power plants worldwide (Source: Figure prepared by L J Patrick Muffler and Ellen Lougee, U.S Geological Survey) Geothermal resources are more readily accessible: • Above 20 ℃ (68 ℉) : direct uses like greenhouses, aquaculture and district heating • Above 75 ℃ (167 ℉) the water is hot enough to be used for electricity generation using binary cycle technology • Above 160 ℃ (320 ℉) flash steam generation can be used to produce clean, renewable electricity Alternative Geothermal • The geothermal gradient is the rate of increase of temperature with Sources increasing depth in the earth • Where geothermal gradients are at least 40°C/ kilometer, even in the absence of much subsurface water, the region can be regarded as a potential geothermal resource of the hot-dry-rock type • Most of the regions identified as possible hot-dry-rock geothermal fields in the United States are in thinly populated western states with restricted water supplies • The area east of the Rocky Mountains has a geothermal gradient and surface heat flow typical of world average continental crust; • The faster temperature increases with depth, the closer to the surface are usefully warm rocks, and—all else being equal— the greater the geothermal-energy potential ADVANTAGE Where most feasible, geothermal power is quite competitive economically with conventional methods of generating electricity The use of geothermal steam is also pollution-free DISADVANTAGE • only be used for a period of time—a few decades, on average— before the rate of heat extraction is seriously reduced • not only are geothermal power plants stationary, but so is the resource itself inefficient • cannot contribute to such energy uses as transportation SUMMARY • We find an almost bewildering variety of alternatives available • Some of the already-viable have limited ultimate potential (e.g., hydropower, geothermal power) • Nuclear fission produces minimal emissions but entails waste-disposal problems, and concerns about reactor safety • The fuel reprocessing necessary if fission-power use is greatly expanded raises security concerns • Solar and wind energy, though free and clean to use, are so diffuse, and so variable over time and space • Biofuels, like fossil fuels, yield carbon dioxide (and perhaps other pollutants also), and may require substantial expansion of cropland PREFERENCE • environmental geology - 9thedition-carla w montgomery • geology facing the c – jon erickson • http://123doc.org/document/2824438-slide-thuyet-trinh-bao-cao-cac -nguon-nang-luong-thay-the-de-tai-nang-luong-dia-nhiet.htm?page=7 [...]... tsunami that was triggered by the Tōhoku earthquake on 11 March 2011 Nuclear energy is increasing And accounting for a large proportion of the world 's energy resources II ENERGY OCEANS Three different approaches Harnessing the energy of waves Harnessing the energy of tides Ocean thermal energy conversion (OTEC) 1 Harnessing the energy of tides • Tides represent a great volume of shifting water • A commercial... equipment • Solar energy is free although there is a cost in the building of ‘collectors’ and other equipment require • Solar energy does not cause pollution • Solar energy can be used in remote areas where it is too expensive to extend the electricity power grid • Solar energy is infinite • Solar energy can only be harnessed when it is daytime and sunny • Solar collectors, panels and cells are relatively... used to create ocean energy III SOLAR ENERGY • The earth intercepts only a small fraction of the energy radiated by the sun Much of that energy is reflected or dissipated in the atmosphere • The two areas in which solar energy can make the greatest immediate contribution are in space heating and in the generation of electricity, uses that together account for about two-thirds of U.S energy consumption... plant requires at least 5 meters difference between high and low tides for efficient generation of electricity and a bay or inlet with a narrow opening that could be dammed to regulate the water flow in and out Tidal-power generation uses flowing water to generate electricity, as with conventional hydropower 2 Harnessing the energy of waves The up -and- down motion of the water can be harnessed in various... temperature difference between warm surface water and the cold water at depth •The temperature difference between warm and cold seawater must be at least 40°F (22°C) year-round, which is true only near the equator Given the thermal and other requirements of OTEC, tropical islands are likely to be the first sites for its development (After National Renewable Energy Lab) ADVANTAGE • It does not produce green... Don’t require much maintenance, and will last longer than tradition power plants • Daily • It does not have a big environmental impact DISADVANTAGE • If using tidal energy, it can only supply power for about 10 hours a day because of the pattern of the tides • Machines and technologies are expensive • There are very few locations to build these barrages • Intense waves may result in the damage of some... electricity These systems too are clean and renewable However, appropriate sites are limited by concerns over the visual impact of the equipment in coastal areas, and over possible disruption of natural sediment-transport patterns These issues, together with relatively high costs, have so far prevented widespread development of wave energy Wave Profile Devices 3 Ocean thermal energy conversion (OTEC) •Is another... system-ECCS 4 Emergency electrical system 5 Containment systems 6 Standby gas treatment-SBGT 7 Ventilation and radiation protection Three Mile Island near Harrisburg, Pennsylvania; damaged reactor remains shut down, while others are still operative (© Doug Sherman/Geo file) Fukushima incident The Fukushima Daiichi nuclear disaster was an energy accident at the Fukushima I Nuclear Power Plant, initiated... countries such as the UK, the unreliable climate means that solar energy is also unreliable • Solar power is used to charge batteries so that solar powered devices can be used at night They need replacing from time to time IV WIND ENERGY • Wind power has been utilized to some extent for more than two thousand years; the windmills of the Netherlands are probably the best-known historic example there is... Inc./Doug Sherman, photographer) *ADVANTAGE • It is clean and, like sunshine, renewable indefinitely (at least for 5 billion years or so) • Erratic, highly variable in speed both regionally and locally *DISADVANTAGE • The electricity can be transmitted without excessive loss in the power grid • Interference with and deaths of migrating birds and bats; • The noise associated with a large number of windmills