PDF Publication Title:
Text from PDF Page: 002
Geothermal Power Technology KENNETH H. WILLIAMSON, RICHARD P. GUNDERSON, GERALD M. HAMBLIN, DARRELL L. GALLUP, AND KEVIN KITZ Invited Paper In 1999, 8 GW of electrical generating plant worldwide was powered by geothermal heat. Geothermal sources generated 49 ter- awatt hours of virtually pollution-free power that year. Coal- or oil- fired plants generating this amount would discharge 40 million tons per year of carbon dioxide into the atmosphere. Geothermal capacity has doubled in the past 20 years, and increased 17% in the past five years. The United States and the Philippines account for 50% of that installed capacity worldwide. Thethermalenergystoredintheupper10kmoftheearth’scrust is vast. For example, below the land surface of the U.S., it is es- timated to be 10 times annual energy demand for the country, but most of it is not economically accessible. The only thermal en- ergy currently economic to extract is from sites where temperatures Geothermal power projects convert the energy contained in hot rock into electricity by using water to absorb heat from the rock and transport it to the earth’s surface, where it is converted to electrical energy through turbine-genera- tors. Water from high-temperature 240 C reservoirs is partially flashed to steam and heat is converted to mechan- ical energy by passing steam through low-pressure steam tur- bines. A small fraction of geothermal generation worldwide is generated using a heat exchanger and secondary working fluid to drive the turbine. Exploitable geothermal reservoirs exist in high-tem- perature, highly permeable, fluid-filled rock within the earth’s upper crust, typically in areas associated with young volcanic rocks. Driven by heat loss from underlying magma, hot fluids rise along pre-existing zones of high permeability. The buoyant up-flowing fluids enhance the permeability of the rocks through which they are flowing by chemical leaching and by explosive boiling. If the system becomes large enough and has high enough permeability, it has the potential to be a commercial grade geothermal reservoir with temperatures typically in the range 240 C–320 C (Fig. 2). Current drilling technology can economically ex- ploit geothermal reservoirs in the depth range 500–3000 m. It is estimated that more than 97% of current geothermal production is from magmatically driven reservoirs. More than 90% of exploited fields were “liquid-dominated” under pre-exploitation conditions with reservoir pressures increasing with depth in response to a liquid-phase density. “Vapor-dominated” systems, such as The Geysers in Cal- ifornia, have vertical pressure gradients controlled by the density of the steam. Geothermal reservoirs may also develop outside regions of recent volcanic activity, where deeply penetrating faults allow groundwater to circulate to depths of several kilome- ters and become heated by the geothermal gradient. Vertical temperature gradients [3] typically range from 10 C/km to 80 C/km so, for example, in a gradient of 50 C/km ground- water circulating to depths of 4–5 km may increase in tem- perature above 200 C before flowing upwards under buoy- above 200 reservoirs of hot water or steam exist in the subsurface. C are easily accessible by conventional drilling, and To unlock a significant fraction of this vast energy source major technological advances are needed. These include improvements in drilling technology to lower the cost of wells, in fracture stimula- tion technology to create and control permeability in tight rocks, and in geophysical and chemical tracer technology to characterize thermal and hydraulic regimes in the subsurface. This will take a coordinated effort by government and industry over one or two decades. Keywords—Geothermal power, heat mining, hot dry rock, hot springs, hydrothermal systems, renewable energy, sustainable en- ergy. I. INTRODUCTION The worldwide power output from geothermal sources in- creased from 2.6 terawatt hours/year (TWh/yr) in 1960 to 49 TWh/yr in 1999 as the installed geothermal plant capacity increased from 386 MW in 1960 to 7974 MW in 1999 [1]. Seventy-five percent of the worldwide capacity is produced from the 20 sites with more than 100 MW installed gener- ating capacity (Fig. 1). Manuscript received March 26, 2001; revised July 10, 2001. K. H. Williamson, R. P. Gunderson, G. M. Hamblin, and D. L. Gallup are with the Geothermal Technology & Services, Unocal Corporation, Santa Rosa, CA 95401 USA (e-mail: kwilliamson@unocal.com; Rgun- derson@unocal.com; Jmhamblin@unocal.com; Dgallup@unocal.com). K. Kitz is with the Philippine Geothermal Inc. (Unocal Corporation), Makati City 1226, Philippines (e-mail: kevin.kitz@unocal.com). Publisher Item Identifier S 0018-9219(01)10841-8. PROCEEDINGS OF THE IEEE, VOL. 89, NO. 12, DECEMBER 2001 1783 0018–9219/01$10.00 © 2001 IEEE 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 |