Design optimisation and resource assessment for tidal-stream renewable energy farms using a new continuous turbine approach

• Published in: Renewable energy Vol. 99; pp. 1046 - 1061
• Main Authors: Funke, S.W., Kramer, S.C., Piggott, M.D.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2016
• Subjects: Marine renewable energy; Optimisation; Pentland Firth; Resource assessment; Shallow water equations; Tidal stream turbines; Shallow water equations; Tidal stream turbines; Resource assessment; Marine renewable energy; Optimisation; Pentland Firth
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2016.07.039

This paper presents a new approach for optimising the design of tidal stream turbine farms. In this approach, the turbine farm is represented by a turbine density function that specifies the number of turbines per unit area and an associated continuous locally-enhanced bottom friction field. The farm design question is formulated as a mathematical optimisation problem constrained by the shallow water equations and solved with efficient, gradient-based optimisation methods. The resulting method is accurate, computationally efficient, allows complex installation constraints, and supports different goal quantities such as to maximise power or profit. The outputs of the optimisation are the optimal number of turbines, their location within the farm, the overall farm profit, the farm's power extraction, and the installation cost. We demonstrate the capabilities of the method on a validated numerical model of the Pentland Firth, Scotland. We optimise the design of four tidal farms simultaneously, as well as individually, and study how farms in close proximity may impact upon one another. [Display omitted] •The tidal farm layout problem is formulated as PDE-constrained optimisation problem.•Tidal farms are represented by a density function and optimised for maximum profit.•We show consistency with a previous approach and predict the optimal turbine number.•The hydrodynamic model is validated against observations in the Pentland Firth.•We optimise 810 turbines in four tidal farms and study their impact on each other.