Electric Utility

Table 9. Fuel for Electric Utility Generation of Electricity 1970—1990, kW h x 10 ...

There has been increased interest in firing wood waste as a supplement to coal in either pulverized coal (PC) or cyclone boilers at 1—5% of heat input. This appHcation has been demonstrated by such electric utilities as Santee-Cooper, Tennessee Valley Authority, Georgia Power, Dehnarva, and Northern States Power. Cofiring wood waste with coal in higher percentages, eg, 10—15% of heat input, in PC and cyclone boilers is being carefully considered by the Electric Power Research Institute (EPRI) and Tennessee Valley Authority (TVA). This practice may have the potential to maximize the thermal efficiency of waste fuel combustion. If this practice becomes widespread, it will offer another avenue for use of fuels from waste. 

Hydrogen-storage alloys (18,19) are commercially available from several companies in the United States, Japan, and Europe. A commercial use has been developed in rechargeable nickel—metal hydride batteries which are superior to nickel—cadmium batteries by virtue of improved capacity and elimination of the toxic metal cadmium (see BATTERIES, SECONDARYCELLS-ALKALINe). Other uses are expected to develop in nonpolluting internal combustion engines and fuel cells (qv), heat pumps and refrigerators, and electric utility peak-load shaving. 

Multielevation piperacks are usually needed to handle all the required services for piping, electrical, utilities, and instmmentation. The two-level rack is one of the most common but three-level ones are also used. The utility lines are usually mn in the upper level and the process lines in the lower levels. The larger-diameter lines are located to the outside of the rack to be closest to the column supports. Access platforms are required at the battery limit to provide operators access to the block valves and blinds. If long mns of hot pipe are required, a portion of the pipe rack needs to be dedicated to an expansion loop. A horizontal space in the piperack is provided for a set of lines to be flat-turned into a set of expansion loops with the large pipes located on the outside. AH of the pipe turns are in the same horizontal plane, which is an exception to normal piping practice. A flat turn takes up and blocks space for other pipes. Flat turns are generally only made from the outside of the rack to minimize this blockage. 

Table 1. Estimated Emissions from Fossil-Fueled Steam-Electric Generating Units at U.S. Electric Utilities, 10 t ...

L. S. Hyman, A.merica s Electric Utilities Past, Present, and Future, Pubhc Utihties Reports Inc., 1983. 

EEI Pockethook of Electric Utility Statistics, Edison Electric Institute, Washington, D.C. 

Asbestos Control and Replacements Guidelines for Electric Utilities, Electric Power Research Institute, Palo Alto, Calif., and Empire State Electric Energy Research Corp., N.Y., Aug. 1994. 

Zinc—bromine storage batteries (qv) are under development as load-leveling devices in electric utilities (64). Photovoltaic batteries have been made of selenium or boron doped with bromine. Graphite fibers and certain polymers can be made electrically conductive by being doped with bromine. Bromine is used in quartz—haUde light bulbs. Bromine is used to etch aluminum, copper, and semi-conductors. Bromine and its salts are known to recover gold and other precious metals from their ores. Bromine can be used to desulfurize fine coal (see Coal conversion processes). Table 5 shows estimates of the primary uses of bromine. 

Electric Power Generation. Coal is the primary fuel for thermal electric power generation. Since 1940 the quantity of bituminous coal consumed by electric utilities has grown substantially in each successive decade, and this growth is expected to continue for many years. Coal consumed by electric utilities increased from about 536 x 10 t in 1981 to 689 x 10 t in 1989 (2). The reasons for increased coal demand include availability, relative stability of decreasing coal prices, and lack of problems with spent fuel disposal as experienced in nuclear power plants (see Nuclearreactors). 

Scientific Apparatus Manufacturers Association (SAMA). The fossil-fuel electric utility industiy generally follows this standard. 

Fossil-Fuel-Fired Steam Generators for Which Construction Commenced after August 17, 1971 Electric Utility Steam Generating Units for Which Construction Commenced after September 18, 1978... 

Acid deposition occurs when sulfur dioxide and nitrogen oxide emissions are transformed in the atmosphere and return to the earth in rain, fog or snow. Approximately 20 million tons of SOj are emitted annually in the United States, mostly from the burning of fossil fuels by electric utilities. Acid rain damages lakes, harms forests and buildings, contributes to reduced visibility, and is suspected of damaging health. 

Fossil fuel and electric utility steam generatof" l>73 MW (>250 million BTU/hr) input] (264 KJ/hr) Incinerators ... 

Out of the 900 million tons of coal produced in the United States for domestic purposes in 1992, about 34 million tons were used for coking [10]. The overw helmmg majority of coal is consumed by the electric utilities. Nevertheless, in 1990, the United States steel industry required about 23 million tons of coke which was produced by the byproduct recovery slot oven [15] For a typical blast furnace, this translates to 0 5 tons of coke per ton of iron metal. 

The COP s of specific air conditioners will vary widely with both manufacturer and application. Electricity utility efficiencies will also differ between countries. However, the reason for the economic interest in heat-driven cycles remains clear. Given that primary fuels can cost the consumer approximately 25% of the cost of electricity and that electricity frequently costs more at times of peak demand, there is justification for considering alternative systems. The use of a primary fuel at the point of use can also reduce COj and other emissions. 

As of 2000, it also looks as though more and more electric utilities are becoming interested in fuel cell stacks as local microgenerators to top up power from large power stations, without the need for long-distance transmission of electricity and its attendant expense and power losses. 

The United States generates about 20 million metric tons of nitrogen oxides per year, about 40% of which is emitted from mobile sources. Of the 11 million to 12 million metric tons of nitrogen oxides that originate from stationary sources, about 30% is the result of fuel combustion in large industrial furnaces and 70% is from electric utility furnaces. 

The pollutant ouqiuts from the refining facilities, however, are modest in comparison to the pollutant outputs realized from the consumption of petroleum products by the transportation sector, electric utilities, chemical manufacturers, and other industrial and commercial users. 

The operating cost for air com ession is basically the electric utility needed for the isentropic compression. Electric energy needed to compress air may be calculated using the following expression ... 

Major sources for emissions of SO, and NO, m the United States are presented in Figures 3 and 4 respectively. Approximately two-thirds of the SO, emissions are from electric utilities. Efforts to reduce SO, emissions both nationally and regionally have focused on electric utilities. The CAAA of 1990 have stipulated a reduction of 9.1 million metric tons (10 million short tons) of SO, below 1980 levels, with most of this reduction coming from coal-fired power plants. Implementation of Phase I reductions (199.5-2000) has been successful and has resulted in an 18 percent decline in SO, emissions from electric utilities, compared with 1990 SO, emissions. There has been a 16 percent decline in SO, for this time period when all sources are considered. Phase 2 of the CAAA, which is designed to reduce SO, emissions from electric utilities by another 20 percent... 

National sulfur dioxide emissions by source category, 1997. Electric utilities account for almost two-thirds of SO2 emissions, even after initial implementation of the CAAA of 1990. Total SO2 emissions for 1997 were 18.5 million metric tons. 

During prolonged heat waves which can cause blackouts and brownouts, electric utilities always request that customers limit energy consumption by raising thermostats and turning off the air conditioning when not home. It is uncertain if these requests are heeded, and if they arc, it is uncertain whether conformity is out of altruism (help the utilities) or self-interest (save money). 

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