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This paper presents a spreadsheet-based optimization program that was developed to help make a management decision on how much electricity and steam should be generated by each of the dual power plants and sold to each group of the customer during peak hours and off-peak hours to achieve the maximum profit without violating their sales contractual agreements. Several quantitative determination processes of unit cost, prices and profits were constructed to help understand the calculation procedure hierarchically and embedded into the program. The mathematical linear programming models for optimizing the total profit during both periods of time of use were formulated. Two feasible scenarios for each period of peak hours and off-peak hours towards profit maximization attainment were simulated. The simulation results show that the optimal scenario between the two is applicable to be executed in both periods of time of use. Although some electricity demand could not be fully satisfied and the company had to be penalized financially, this scenario provided the total maximum profit and was able to satisfy the pow-er systems and the legal constraints and not severely violate the sales contractual agreements relative to another scenario. The results from sensitivity analysis show strong effects on the profitability allowing to examine a series of possible changes that will not affect the optimal solution of economic dispatch management.
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