Smith EGR 325 - Modeling of Cost-Rate Curves

Unformatted text preview:

5.0 Economic dispatch and convexity of objective functions in optimization(Inequality constraints may be handled by checking the resulting solution against them, and for any violation, setting up another equality constraint which binds the given decision variable to the limit which was violated).Because Z is convex, and because g is linear (and therefore also convex), we can be certain that application of the above equations will result in the unique minimum cost solution.As seen in Section 4.0 above, combined cycle units do not have convex objective functions. As a result, generation owners which utilize combined cycle units must use special techniques to solve the EDC problem. Some of these techniques are listed in the following:ReferencesModeling of Cost-Rate Curveswww.ee.iastate.edu/~jdm/EE457/Cost RateCurves .docJim McCalley ?1.0 Costs of Generating Electrical EnergyThe costs of electrical energy generation arise mainlyfrom three sources: facility construction, ownershipcosts, and operating costs. The last is the mostsignificant portion of power system operation, and inthis section we focus on this aspect.2.0 Operating CostsThese costs include the costs of labor, but they aredominated by the fuel costs necessary to produceelectrical energy (MW) from the plant. Some typicalaverage costs of fuel are given in the following tablefor coal, petroleum, and natural gas. Average costs ofuranium are about $0.65/MBTU.One should note in particular that - The difference between lowest and highest averageprice over this 11 year period for coal, petroleum,and natural gas are by factors of 1.17, 2.2, and2.71, respectively, so coal has had more stableprice variability than petroleum and natural gas. - During 2003, coal is $1.27/MBTU, petroleum$4.45/MBTU, and natural gas $5.36/MBTU, so1coal is clearly a more economically attractive fuelfor producing electricity.Table 1: Receipts, Average Cost, and Quality of Fossil Fuels for the ElectricPower Industry, 1991 through 2003, obtained from [1]Table 4.5. Receipts, Average Cost, and Quality of Fossil Fuels for the Electric Power Industry, 1992 through 2003 Period Coal[1] Petroleum[2] Natural Gas[3]All FossilFuelsReceipts(thousandtons) Average Cost Avg.SulfurPercentbyWeight Receipts(thousandbarrels)Average Cost Avg.SulfurPercentbyWeight Receipts(thousandMcf) AverageCost(cents/10 6 Btu) AverageCost(cents/ 106 Btu) (cents/10 6Btu) (dollars/ton) (cents/10 6Btu)(dollars/barrel)1992 775,963 141.2 29.36 1.29 147,825 251.4 15.87 1.19 2,637,678 232.8 158.9 1993 769,152 138.5 28.58 1.18 154,144 237.3 14.95 1.34 2,574,523 256.0 159.4 1994 831,929 135.5 28.03 1.17 149,258 242.3 15.19 1.23 2,863,904 223.0 152.5 1995 826,860 131.8 27.01 1.08 89,908 256.6 16.10 1.21 3,023,327 198.4 145.2 1996 862,701 128.9 26.45 1.10 113,678 302.6 18.98 1.26 2,604,663 264.1 151.8 1997 880,588 127.3 26.16 1.11 128,749 273.0 17.18 1.37 2,764,734 276.0 152.0 1998 929,448 125.2 25.64 1.06 181,276 202.1 12.71 1.48 2,922,957 238.1 143.5 1999 908,232 121.6 24.72 1.01 145,939 235.9 14.81 1.51 2,809,455 257.4 143.8 2000 790,274 120.0 24.28 0.93 108,272 417.9 26.30 1.33 2,629,986 430.2 173.5 2001 762,815 123.2 24.68 0.89 124,618 369.3 23.20 1.42 2,148,924 R 448.7 173.0 2002[4] 884,287 125.5 25.52 0.94 120,851 334.3 20.77 1.64 5,607,737 356.0 151.5 2003[5] 1,026,281 127.5 25.91 0.94 205,283 445.1 27.34 1.55 5,479,821 536.6 218.7 [1] Anthracite, bituminous coal, subbituminous coal, lignite, waste coal, and synthetic coal. [2] Distillate fuel oil (all diesel and No. 1, No. 2, and No. 4 fuel oils), residual fuel oil (No. 5 and No. 6 fuel oils and bunker C fuel oil), jet fuel, kerosene, petroleum coke (converted to liquid petroleum, see Technical Notes for conversion methodology), and waste oil. [3] Natural gas, including a small amount of supplemental gaseous fuels that cannot be identified separately. Natural gas values for 2001 forward do not include blast furnace gas or other gas. [4] Beginning in 2002, data from the Form EIA-423, "Monthly Cost and Quality of Fuels for Electric Plants Report" for independent power producers and combined heat and power producers are included in this data dissemination. Prior to2002, these data were not collected; the data for 2001 and previous years include only data collected from electric utilities via the FERC Form 423. [5] For 2003 only, estimates were developed for missing or incomplete data from some facilities reporting on the FERCForm 423. This was not done for earlier years. Therefore, 2003 data cannot be directly compared to previous years' data. Additional information regarding the estimation procedures that were used is provided in the Technical Notes. R = Revised. Notes: Totals may not equal sum of components because of independent rounding. Receipts data for regulated utilities are compiled by EIA from data collected by the Federal Energy Regulatory Commission (FERC) on the FERC Form 423. These data are collected by FERC for regulatory rather than statistical and publication purposes. The FERC Form 423 data published by EIA have been reviewed for consistency between volumes and prices and for their consistency over time. Nonutility data include fuel delivered to electric generating plants with a total fossil-fueled nameplate generating capacity of 50 or more megawatts; utility data include fuel delivered to plants whose total fossil-fueled steam turbine electric generating capacity and/or combined-cycle (gas turbine with associated steam turbine) generating capacity is 50 or more megawatts. Mcf = thousand cubic feet. Monetary values are expressed in nominal terms. Sources: Energy Information Administration, Form EIA-423, "Monthly Cost and Quality of Fuels for Electric Plants Report;" Federal Energy Regulatory Commission, FERC Form 423, "Monthly Report of Cost and Quality of Fuels for Electric Plants." 2Despite the high price of natural gas as a fuel relativeto coal, the past 10 years have seen new gas-firedplants far outpace new coal-fired plants, with gas orpetroleum-gas fired plants accounting for over 99%of new capacity in this time period [2]. The reasonfor this has been that natural-gas-fired plants havelower capital costs, higher fuel efficiency, shorterconstruction lead times, and


View Full Document

Smith EGR 325 - Modeling of Cost-Rate Curves

Download Modeling of Cost-Rate Curves
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Modeling of Cost-Rate Curves and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Modeling of Cost-Rate Curves 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?