energy distribution

1.14 The follow J on WC cual plants? The following table gives capital costs and variable costs for coal plants, NGCC plants, and natural-gas-fired CTS. Coal Capital cost (S/kW) Variable cost (/kWh) 2000 2.0 NGCC 1200 4.0 800 6.0 This is a municipal utility with a low fixed charge rate of 0.10/yr for capital costs. Its load duration curve is shown below. Demand (MW) 0 1000 2000 6000 7000 8000 9000 3000 4000 5000 Hours/year FIGURE P1.14 a. On a single graph, draw the screening curves (Revenue required $/yr- kW vs. h/yr) for the three types of power plants (like Figure 1.29). b. For a least-cost system, what is the maximum number of hours a CT should operate, the minimum number of hours the coal plant should operate, and the range of hours the NGCC plants should operate. You can do this algebraically or graphically. How many MW of each type of power plant would you recommend? 0.0 800 0.2 Capacity factor 0.4 0.6 9,8 CF = 0.7 600 Fixed costs $218/yr-kW Total costs line TO Revenue required ($/yr-kW) 400 $579/yr-kW 200 Slope = 579 / 6132 = $0.1017/kWh 0.7 x 8760 = 6132 hrs/yr 2000 4000 6000 8000 8760 Equivalent hours per year at rated power FIGURE 1.29 A graphical presentation of Examples 1.2 and 1.3. The average cost of electricity is the slope of a line drawn from the origin to the revenue curve that corresponds to the capacity factor