Optimal design of tidal power plants: The effects of alternative criteria

The design of tidal power plants is one of the most important engineering challenges in Canada. In a previous study sponsored by the Bay of Fundy Tidal Power Review Board, consulting firms developed detailed civil, mechanical and electrical designs for plant subsystems. They gathered extensive data on the tidal basins and then used the criterion of minimum “at-site cost of energy” to design the tidal power plant at a given location. This paper focusses on a new optimization model in which the economic design of the plant depends on the characteristics of the electric power system in which it is embedded. We incorporate the data from the previous study into our optimization model to obtain the two different views of the economic design problem, one based on the criterion of maximum net benefits and the other on maximum benefit-cost ratio. The computational results give the optimal design for each of the new criteria and the sensitivity of each design to changes in some system parameters and design variables. We show that the strengths and weaknesses of criteria such as net benefits and benefit-cost ratio differ from those of the “at-site cost of energy” criterion used in the previous study. The appendices describe the new optimization model in greater detail and clarify the computational results with analytic results displaying similar properties.