South Carolina State Water Assessment, 2Nd Ed., Chapter 9
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SPECIAL TOPICS SPECIAL TOPICS Power Commission, 1970). Power from the company's Columbia Canal facility was first sold to local mills and Water-resource activities and concerns are numerous then later used to power streetcars and streetlights in and varied. Some have been presented earlier in the the city of Columbia. South Carolina Electric and Gas statewide overview and the subbasin analyses; however, Company (SCE&G) now operates this facility. many water-resource topics require more in-depth coverage and/or do not lend themselves to the statewide The Lower Pelzer Hydroelectric facility, built in 1895 or subbasin presentation format. While many topics could on the Saluda River in Williamston, a town about 30 miles be presented in this section, the most important were south of Greenville, is said to be the first facility to use selected to give the reader a balanced overview of water- overhead wires to transmit electricity long distances, resource concerns. providing power to the Pelzer Manufacturing Company located a few miles upstream of the project (Enel North The special topics in order of presentation are: America, 2004). The Lower Pelzer project was inducted Hydroelectric power into the Hydro Hall of Fame for 100 years of continuous FERC relicensing operation. Another milestone in South Carolina's Instream flow needs hydropower development was the transmission of power from Portman Shoals to Anderson in 1897, the longest Navigation distance of electric power transmission in the United States River conservation at the time (Confederation of South Carolina Historical Aquatic nuisances Societies, 1978). Such long-distance power transmission Water recreation allowed for development of remote hydropower sites. Sedimentation in surface waters Types of Facilities Unique wetland areas Hydropower has experienced tremendous growth Coastal concerns and change since its beginnings. Hydroelectric power Saltwater contamination facilities range in size from small developments with Aquifer storage and recovery little storage to large dams with several turbines. Smaller Water conservation facilities often depend entirely on streamflow and are Interbasin transfers referred to as run-of-river plants; these were the type most frequently constructed in the early days of hydroelectric Drought management and mitigation development. Today, a single hydropower facility may Flooding impound thousands of acre-feet of water and produce HYDROELECTRIC POWER thousands of mega-watt hours of energy. Not until the mid-1800's were turbines developed Besides the numerous technological improvements that could efficiently produce electricity from flowing that have allowed for more efficient production of water. Beginning in the 1880's, the Nation as well as electricity, many new concepts in hydropower production the State saw a dramatic increase in the development have been developed. One of the most important of these of hydroelectric power. The Piedmont region of South is the development of pumped-storage facilities. At a Carolina, with its abundance of free-flowing waters and conventional hydropower facility, water released from relatively high relief, was ideally suited for this type of a reservoir through turbines to produce electricity is lost development. Industry quickly took advantage of these downstream, whereas at a pumped-storage site, some conditions and built factories with hydropower facilities of the released water is retained in a tailwater pool and at many sites, thus providing each factory with its own is later pumped back into the headwater pool to be used source of electricity. In 1895, the Columbia Water Power again to generate more electricity. This is made possible by Company became the first company to commercially reversible pump turbines, which serve as both generators— produce electricity in South Carolina (Kohn, 1910; Federal creating electricity when water is passed through them from South Carolina Water Assessment 9-1 upstream to downstream—and pumps—using electricity to operations. These plants are better suited for meeting pump water from downstream back into the upper reservoir. base load demands. Base load is defined as the mean of During periods of high electrical demand when electricity the Monday to Friday minimum loads, plus 10 percent. is relatively expensive, usually weekday mornings and Base load operation of hydropower plants is normally afternoons, electricity is produced by releasing water from confined to those facilities that lack storage (run-of-river) the headwater pool through the pump turbines and into the or those that must be run continually to meet downstream tailwater pool. Later, during periods of low electrical demand flow requirements. Hydropower plants are well suited for when electricity is relatively inexpensive, usually at night or meeting peak loads (defined as the greatest difference on weekends, the turbines are reversed and used to pump between the Monday to Friday daily peak and the daily water back into the headwater pool where it is stored until load equaled or exceeded 12 hours per day) and reserve needed during another peak-demand time. Although more loads because they have the ability to produce electricity energy is required to pump water back into the headwater on short notice and to stop quickly once demands are met pool than is generated when the water is released, this process or reduced. Newer hydropower plants reflect this use as is economically feasible because the cost of electricity is peaking units; they are designed to operate less than 20 much lower when pumping back water than when releasing percent of the time. The recent and continuing construction water from the upper reservoir. Although pumped-storage of large pumped-storage units also emphasizes the facilities allow water to be used more than once to generate importance placed on hydropower for peaking energy. electricity, not all water within the tailwater reservoir is The distribution of power generated at hydropower retained. Discharges are allowed to satisfy downstream flow plants in South Carolina depends mainly on plant ownership requirements and to compensate for inflow, and some water is and location. Hydropower generated by municipalities or lost to evaporation. There are currently four pumped-storage cooperatives is usually used in the immediate vicinity of facilities in South Carolina: Lake Russell (U.S. Army Corps the plant site. Power produced at Federal projects such as of Engineers), Fairfield Pumped Storage Facility (SCE&G), Lake Thurmond and marketed by the Southeastern Power Bad Creek (Duke Energy), and Lake Jocassee (Duke Energy) Administration is often carried through major transmission (Table 9-1). These facilities have a total capacity of about lines or "wheeled" to distant users. 2,800 MW (megawatts). A modern, sophisticated steam plant may require up Current Facilities to 72 hours to generate enough steam to start producing Currently, 46 hydroelectric plants use the waters in or electricity, making it very expensive to either start or stop adjacent to South Carolina (Figure 9-1). Plants range in 12 6 34 2 4 1 37 13 9 3 30 20 43 38 7 8 44 35 22 11 26 18 28/24 17 27/25 15 19 23 5 LINE 36 39 29 16 10 21 40 14 LL FA 42 46 45 41 31 32 33 EXPLANATION 8 FERC-licensed hydroelectric facility 20 non-FERC-licensed hydroelectric facility 40 Corps of Engineers hydroelectric facility Fall Line 10 0 10 20 30 40 50 miles Figure 9-1. Existing hydroelectric power plants in and adjacent to South Carolina. See Table 9-1 for facility information. 9-2 Chapter 9: Special Topics capacity from less than 1 MW to 1,065 MW (Table 9-1). maximum potential generating capacity of these sites The largest conventional hydropower plant is the U.S. totals 1,450 MW, which could provide an additional 1.7 Army Corps of Engineers’ Hartwell facility, which has million MWH of electricity per year. a capacity of 420 MW, and the largest pumped-storage Four sites in the Saluda River subbasin have been plant is Duke Energy’s Bad Creek facility, which has a identified in the National Hydropower Study as being capacity of 1,065 MW. Total generating capacity of all feasible for development. Three sites occur on the Saluda the hydroelectric plants in or adjacent to South Carolina River and one, a retired hydropower plant, is on the Reedy is about 4,600 MW, which is about 20 percent of the total River. These sites have a total potential capacity of 40.5 capacity of all electricity-generating facilities in the State. MW and could provide almost 77,000 MWH of energy Of the total hydropower generating capacity, 2,800 MW are annually. provided by pumped-storage facilities. Since hydroelectric power plants are generally designed to operate less than Most of the Catawba River, in the Catawba-Wateree 20 percent of the time, yearly outputs are much lower subbasin, has been developed for hydropower production. than these numbers indicate. In 2006, hydroelectric plants A head of 88.5 feet, however, remains undeveloped generated 1,806,948 MWH (megawatt-hours) of energy, between Duke Energy’s existing Lake Wylie and Fishing which was only 1.8 percent of the total energy generated Creek hydropower plants. Two potential hydroelectric sites in the State (U.S. Energy Information Administration, have been identified to utilize this remaining head. These 2009). In comparison, hydroelectric facilities produced 7 sites, Sugar Creek and Courtney Island, could support percent of the country’s electrical power in 2006 (U.S. a total capacity of 77 MW and generate on the average Energy Information Administration, 2008). 253,000 MWH of energy annually. Development of these sites would inundate the Catawba River’s only remaining Duke Energy owns the most hydroelectric facilities free-flowing water and create a chain of hydroelectric in or adjacent to South Carolina, with twelve facilities, reservoirs from the North Carolina boundary to Lake followed by SCE&G, which owns six (Table 9-1).