PDF Publication Title:
Text from PDF Page: 009
Table 1 Land Use at the Gunung Salak 330 MW Project, Indonesia. Total Area is 175 ha (1.75 km ) Pritchett [18] used a numerical model to show that a field whichisproducedatanaveragerateof60MW for50years, if then shut in for 100 years, can subsequently produce for an- other 50 years at an average rate of 40 MW . If left shut-in for 1000 years, thermal recovery is such that 90% of the orig- inal average capacity can be achieved for the next 50 years. This process was not optimized, since the production–injec- tion geometry was not changed to increase the efficiency of heat extraction. In practice it is anticipated that fields which have been operated until pressures and enthalpies have been reduced to uneconomic levels could be subject to a number of modifications designed to boost production at the end of the first period of production, or after an extended shut-in period. Such modifications include placement of new pro- duction and injection sites to take advantage of previously inaccessible heat, and recharge of the reservoir with external fluid in areas still hot, but low in pressure. Time scales for the natural renewal of geothermal systems are of the order of 10 to 10 years, whereas fossil systems renew at time scales of 10 to 10 years. X. ENVIRONMENTAL CONCERNS Geothermal power projects have a number of advantages from an environmental viewpoint: small footprint, no ex- ternal fuel sources requiring excavation, transportation, and storage, and the ability to dispose of unwanted by-products back underground from whence they came. The 330 MW Gunung Salak project [19] in Indonesia will be used as an example in this paper. The area of land utilized for the development of the energy source and the power conversion facilities at Salak is 1.75 km . As many as seven wells are drilled from a single lo- cation so that land use is minimized. Six 55 MW steam tur- bines are housed at two locations, each with three units. Elec- tric-generating stations require only enough land to house steam turbines, generators, switchyards, and cooling towers. Table 1 shows land use requirements at the Salak field. Salak is a liquid-dominated reservoir which generates 3.5 m /s of brine with a dissolved solids content of 19 000 mg/kg along with the steam used for power generation. All the brine is returned to the reservoir through injection wells. The power plant utilizes a condensing turbine, and a second by-product of the process is steam condensate. In Salak, the steam condensate, which has a total dissolved solids content of 100 mg/kg, is used for cooling tower make-up, eliminating the need to use surface waters for cooling. Excess condensate and cooling tower blowdown water are piped to two condensate injection wells and put back into the geothermal reservoir. In some locations it may 1790 be economically feasible to treat the condensate to remove contaminants and use it as a source of industrial, agricultural or potable water [20]. An inventory of products generated at the Salak project is given in Table 2. Cooling towers reject heat from the system, and are designed to limit plumes, water droplet drift, and gases that exsolve during aeration. CO emissions at Salak are roughly an order of magnitude lower than those from fossil-fired plants which average roughly 500–1000 MWh. Sulfur emissions from geothermal plants are also much lower than fossil-fired plants. Traces of H S are encountered in the steam at Salak, and this gas is diluted with air over cooling towers to below Indonesian emission standards of 35 mg/m in the surrounding atmosphere (Table 2). In fields where higher concentrations of H S are encountered, the malodorous gas can be scrubbed and oxidized using commercial abatement processes. During exploitation of geothermal resources, solids are produced in the form of drill cuttings or scale deposits. In Bulalo, Philippines, solid waste is made into a slurry and injected back into the reservoir [21]. In Salak, Indonesia, the waste is used beneficially in construction materials. Geothermal solids can be rendered nonhazardous by cement fixation [22]. XI. CONCLUSION Geothermal energy is abundant, but only a very small fraction can be converted commercially to electricity with today’s technology. From 1980 to 2000, the installed geothermal capacity worldwide doubled, but in the past two years the rate of growth slowed and the geothermal industry has consolidated and downsized. This was due to the following factors. • The most prospective and accessible sites have already been exploited in many developed countries. Many prospective sites are scenic and occur in national parks, inaccessible to development. • Economic problems in Asia in the late 1990s have dis- couraged private developers, particularly in Indonesia, which has abundant resources. • Multilateral lending agency support and government incentives for geothermal development have been re- duced. • Low natural gas prices in the 1990s, and price reduc- tions in fossil-fired power plants, made it more difficult for geothermal power to compete in the marketplace. Geothermal is at a commercial disadvantage to fossil fuels, because the effect of having to drill enough wells to supply full plant capacity at startup is the economic equivalent of purchasing most of the fuel required for the next 20 years in a fossil-fired plant, prior to bringing the plant on-line. However a significant opportunity for geothermal develop- ment is emerging as the carbon credit marketplace forms. Carbon credit trading, once implemented, will allow the clear environmental advantages of geothermal to be realizable to project developers as financial value. As the costs for nat- ural gas increase geothermal power will be able to compete PROCEEDINGS OF THE IEEE, VOL. 89, NO. 12, DECEMBER 2001 Authorized licensed use limited to: National United University. Downloaded on October 10, 2009 at 14:17 from IEEE Xplore. Restrictions apply.PDF Image | Geothermal Power Technology
PDF Search Title:
Geothermal Power TechnologyOriginal File Name Searched:
Geothermal20Power20Technology.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |