U.S.-based GreenFire Energy has announced that it is preparing work on its demonstration project to use supercritical CO2 instead of water as working fluid to carry enthalpy from the resource back to the surface for geothermal power production.
Several of the important health and environmental risks associated with a reference geothermal industry that produces 21,000 MW/sub e/ for 30 y (equivalent to 20 x 10/sup 18/ J) are assessed. The analyses of health effects focus on the risks associated with exposure to hydrogen sulfide, particulate sulfate, benzene, mercury, and radon in air and arsenic in water. Results indicate that emissions of hydrogen sulfide are likely to cause odor-related problems in geothermal resources areas, assuming that no pollution controls are employed. For individuals living within an 80 km radius of the geothermal resources, chronic exposure to particulate sulfate could result in between 0 to 95 premature deaths per 10/sup 18/ J of electricity generated. The mean population risk of leukemia from the inhalation of benzene was calculated to be 3 x 10/sup -2/ cases per 10/sup 18/ J. Exposure to elemental mercury in the atmosphere could produce between 0 and 8.2 cases of tremors per 10/sup 18/ J of electricity. Inhalation of radon and its short-lived daughters poses a mean population risk of 4.2 x 10/sup -1/ lung cancers per 10/sup 18/ J. Analysis of skin cancer risk from the ingestion of surface water contaminated with geothermally derived arsenic more »
The emission of hydrogen sulphide (H2S) during geothermal development is a
significant environmental aspect that must be considered in an environmental
management plan. Wells TR-18 and TR-18A are part of the expansion of the
Berlín geothermal power plant in El Salvador. H2S emissions were estimated for
these two wells during well discharge, and calculated to be 7.1 and 42.8 g/s,
respectively. Maximum H2S concentrations in the air were also determined in the
nearby Bob Graham community using a dispersion model (SCREEN3). Four cases
were evaluated: nominal flow, 35% of the nominal flow, nominal flow with 90%
removal efficiency, and nominal flow with double stack height. Estimated
maximum concentrations in the air in the community were 54.9 and 174.2 (μg/m3
24-hour averaged) during TR-18 and TR-18A well discharges, respectively. These
estimated concentrations exceeded USEPA-California (43 μg/m3
and Icelandic (50 μg/m3
24-hour averaged) regulations.
A THESIS SUBMITTED TO THE GLOBAL ENVIRONEMENTAL SCIENCE
UNDERGRADUATE DIVISION IN PARTIAL FULFILLMENT OF THE
REQUIREMENTS FOR THE DEGREE OF BACHELOR OF SCIENCE IN GLOBAL
Geothermal Public Health and Safety
Hydrogen sulfide: When air levels reach .1ppmv, the onset of headaches, nausea and sinus congestion could occur. Any levels above .1ppmv could result in respiratory paralysis or eye damage. Hydrogen sulfide monitors detect air concentrations to delineate safe levels.
In this report, we have presented data in four sections: (1) THE GEYSERS HISTORICAL UPDATE 1990-2010 – A historical update of the primary developments at The Geysers between 1990 and 2010 which uses as its start point Section IIA of the Monograph – ‘Historical Setting and History of Development’ that included articles by James Koenig and Susan Hodgson. (2) THE GEYSERS COMPREHENSIVE REFERENCE LIST 1990-2010 – In this section we present a rather complete list of technical articles and technical related to The Geysers that were issued during the period 1990-2010. The list was compiled from many sources including, but not limited to scientific journals and conference proceedings. While the list was prepared with care and considerable assistance from many geothermal colleagues, it is very possible that some papers could have been missed and we apologize to their authors in advance. The list was subdivided according to the following topics: (1) Field characterization; (2) Drilling; (3) Field development and management; (4) Induced seismicity; (5) Enhanced Geothermal Systems; (6) Power production and related issues; (7) Environment-related issues; and (8) Other topics. (3) GRC 2010 ANNUAL MEETING GEYSERS PAPERS – Included in this section are the papers presented at the GRC 2010 Annual Meeting that relate to The Geysers. (4) ADDITIONAL GEYSERS PAPERS 1990-2010 – Eighteen additional technical papers were included in this publication in order to give a broad background to the development at The Geysers after 1990. The articles issued during the 1990-2010 period were selected by colleagues considered knowledgeable in their areas of expertise. We forwarded the list of references given in Section 2 to them asking to send us with their selections with a preference, because of limited time, to focus on those papers that would not require lengthy copyright approval. We then chose the articles presented in this section with the purpose of providing the broadest possible view across all technical fields, as related to The Geysers steam-dominated geothermal system. The Geysers has seen many fundamental changes between 1990-2010 and yet the geothermal resource seems still to be robust to the extent that, long after its anticipated life span, we are seeing new geothermal projects being developed on the north and west peripheries of the field. It is hoped that this report provides a focused data source particularly for those just starting their geothermal careers, as well as those who have been involved in the interesting and challenging field of geothermal energy for many years. Despite many hurdles The Geysers has continued to generate electrical power for 50 years and its sustainability has exceeded many early researchers expectations. It also seems probable that, with the new projects described above, generation will continue for many years to come. The success of The Geysers is due to the technical skills and the financial acumen of many people, not only over the period covered by this report (1990-2010), but since the first kilowatt of power was generated in 1960. This Special Report celebrates those 50 years of geothermal development at The Geysers and attempts to document the activities that have brought success to the project so that a permanent record can be maintained. It is strongly hoped and believed that a publication similar to this one will be necessary in another 20 years to document further activities in the field.
4.3 GEOLOGIC PROBLEMS
4.3.1 REGIONAL SETTING
The three Bay Area power plants (Potrero, Contra Costa, and Pittsburg) are located on the western coast of California in the Coast Range Geomorphic Province, which is an area of moderate-to-high seismic activity. Major northwest-trending fault zones, including the San Andreas Fault Zone (the dominant fault zone in California), parallel the coast. All of the fossil-fueled power plants to be divested as part of the project are located within 46 miles of at least one major fault zone and are subject to moderate-to-high seismic activity (see Table 4.3-1 and see Figure 4.3-1).
Read more “PG&E and Sewer Water Used to Frak the Geysers – Increasing Seismic Activity . . Northern California”
Remote Bay Area Geysers Important Source Of California Green Energy Also Produce Small Earthquakes
LAKE COUNTY (KCBS)— It’s the single largest power-generating operation of its kind on the planet and is an important part of California’s green energy portfolio. But hardly anyone in the Bay Area knows what it is or where it is.
The Geysers geothermal fields are about 75 miles north of San Francisco. A drive up a narrow road will lead you to the Mayacamas Mountains with Santa Rosa to the west and Clear Lake to the east. When you arrive, it’s 45 square miles of land, populated by 15 large geothermal power plants.
Magnitude 4.2 Earthquake Strikes Near The Geysers
COBB (CBS SF) — A magnitude 4.2 earthquake was reported at the northern edge of Sonoma County late Monday afternoon, according to the U.S. Geological Survey.
The quake was reported at 4:57 p.m. roughly 24 miles north of Santa Rosa, just three miles outside of the unincorporated community of Cobb in Lake County.