Assume that all three of the thermal units described next are running. Find the economic dispatch schedules as requested in each part. Use the method and starting conditions given. Minimum Maximum Fuel Cost Unit Data (MW) (MW) (S/ MBtu) H, = 225 +8.4P, +0.0025P H, = 729+6.3P, +0.0081P H, = 400+7.5P, +0.0025P 45 350 0.80 %3D 45 350 1.02 %3D 47.5 450 0.90 %3! a. Use the lambda iteration method to find the economic dispatch for a total demand of 450 MW. b. Use the base-point and participation factor method to find the economic schedule for a demand of 495 MW. Start from the solution to part a. c. Use a gradient method to find the economic schedule for a total demand of 500 MW, assuming the initial conditions (i.e., loadings) on the three units are P, = P, = 100 MW and P, = 300 MW Give the individual unit loadings and cost per hour, as well as the total cost per hour to supply each load level: (MBtu=millions of Btu: H=heat input in Btu/h; P = electric power output in MW; i= 1,2,3).