Tidal barrage operation optimization using moment-based control

Abstract

As decarbonization of energy systems becomes imperative and the deployment of intermittent renewables increases, the operation of electrical grids becomes challenging. In this sense, tidal barrage schemes can supply clean and predictable energy with more flexibility than the more traditional wind and solar plants. However, the high infrastructure costs associated with tidal barrage plants, together with ecological and environmental issues, hinder their deployment. An optimal operation is key to maximise energy output and assure project feasibility. Recently, Ringwood and Faedo [1] introduced a novel approach to tidal barrage control by applying momentbased optimal control, previously used to solve wave energy control problems, with promising results. The model consists of a two-way tidal barrage scheme, where an analogy is made between latching/declutching algorithms applied in WEC control and holding/sluicing from tidal barrage operation. This preliminary study has a number of simplifying assumptions, leaving a pathway to further examine the optimal control problem. This paper extends the results of the analysis from [1] by adding enhancements to the model. Minimum and maximum head values are added to account for the turbine’s operational limits. The basin is modelled such that the surface area is a polynomial function of the water level, instead of assuming a constant surface area, which will affect the operational head of the optimal solution. Furthermore, a weighted cost function is introduced to penalise the parasitic energy consumption of the sluice gates, with an analysis of the impact of different weights.