WorldWide Drilling Resource

14 OCTOBER 2021 WorldWide Drilling Resource ® Dry Steam Geothermal Generates Power Compiled by the Editorial Staff of WorldWide Drilling Resource ® The United States leads the world in geothermal electricity production, gener- ating 3567 megawatts of power with another 1270 megawatts of additional proj- ects in development. To tap into this energy, heat must be carried to the surface with fluid circulation through any number of taps, including magma chambers, hot springs, drilled wells, and hydrothermal transmission. The largest geothermal power plant in the world, in terms of power capacity, is actually a massive geother- mal complex of power plants known as The Geysers in California. The Geysers geothermal field actually has no natural geysers anywhere in the Geysers-Clear Lake area. Because of the fumarolic activity and steam rising from hot springs, the namewas derived from early explorers. Naturally occurring steam field below the earth’s surface are found in the Mayacamas Mountains, 75 miles north of San Francisco, cover- ing 29,000 acres (45 square miles) in the counties of Sonoma, Lake, and Mendocino. The Geysers draws steam from 350 production wells. There are 18 currently operating geothermal plants with a combined capac- ity of 1517 megawatts of electricity around the clock, enough to power 900,000 homes. The Geysers is unique with its high-temperature, dry steam resource, which can be directly used to move turbines and generate electricity. The steam is har- nessed from a greywacke sandstone reservoir located at the top of a mix of low- permeability rocks. Since the reservoir rock is primarily a relatively brittle type of sandstone unit broken by fractures, the steam is easily transmitted. A large molten rock chamber, spanning four miles belowground with a diameter greater than eight miles, heats the steam reservoir. The deepest well is 12,900 feet, over two miles belowground, and the average well depth is 8500 feet. Steam is brought to the surface through pipes and then supplied to a network of interconnected power plants with 80 miles of pipelines. There, the steam spins conventional steam turbines, which runs the generators, producing electricity. Accounting for 20% of the clean power generated in California, The Geysers supplies electricity to Sonoma, Lake, Mendocino, Marin, and Napa counties. This valuable reservoir, one of California’s most reliable sources for energy, experienced a reduced flow of steam across the geothermal field in the late 1980s. Today, it is recharged by an average injection of over 15 million gallons of treated wastewater daily to produce additional electricity. Piped up to 50 miles from its source at the Lake County Sanitation waste water treatment plants and the city of Santa Rosa, the treated wastewater is sent through the 54 injection wells into the steam field. This not only increases the power generated but also protects the local waterways, lakes, and other surface waters from becoming polluted. Geothermal power is considered a sustainable, renewable source of energy since the heat extraction is negligible when compared to the earth’s internal heat budget, which is estimated at 47 terawatts (47 trillion watts). Of the nearly two dozen geothermal power plants located at The Geysers, 15 are owned by Calpine Corporation, with the others owned by the Northern California Power Agency and Santa Clara’s Electric Utility. Photo of The Geysers courtesy of Calpine Corporation. GEO Atlantis Vault • Self - Contained • Simple installation • Trouble - free operation For more information call: (270) 786-3010 or visit us online: How Much Water does it Take? You may be surprised to learn just how much water is used to create items we use every day. Here are a few examples: Smartphone = 3190 gallons Bed Sheet = 2839 gallons A Pair of Jeans = 2108 gallons Cotton T-shirt = 659 gallons 1 Pound of Plastic = 22 gallons Car = Between 13,737 & 21,926 gallons 1 Pound of Beef = 1799 gallons A 6 Ounce Steak = 674 gallons 1 Slice of Bread = 11 gallons 1 Apple = 18 gallons 1 Pound of Chocolate = 3170 gallons 1 Gallon of Wine = 1008 gallons