The Energy Yield Impacts of Wind Farm Design and Location

It is notoriously difficult to improve the accuracy of predicting energy yield for wind farms due to the balance between computational power, time, and accuracy. This is a real world problem for wind farm developers, society, and the environment, because it leads to less than optimal energy yield from a site and may lead to some sites not being developed. This thesis addresses this problem by experimenting with the development of a new hybrid computational fluid dynamics approach to wind farm design based on combining established engineering theory. Actuator disc theory used for replicating the far wake of a wind turbine is validated using wind tunnel experiments and computational fluid dynamics simulations. The technique is then combined with a high fidelity full rotor model to produce a novel hybrid methodology for efficiently analysing wind turbine performance while in the wake of another. Using the new hybrid technique a set of reference cases was completed to produce an understanding of how the layout of multiple wind turbines affects performance. The wider contribution to engineering is that detailed turbine blade analysis while in the wake of another wind turbine is possible without having to intrinsically model multiple high fidelity rotors, which reduces computational cost and time. A novel feature of the PhD was to develop the theoretical method with an understanding of the importance of real-world application. This was gained through investigation of the approach currently taken by wind farm developers and the ways in which better information about siting decisions might work with the details of the planning consent regime. Using the knowledge gained from studying energy policy and the computer simulated reference cases, a case study was performed on an existing wind farm. Suggestions are made to improve the power output from the site and a discussion of the potential policy implications of the results are considered. Improved predictive capacity can lead to significant improvements in a context where the location of wind turbines is fixed in planning consent. The Blackstone Edge wind farm case study reveals that marginal changes in wind turbine siting as a result of novel simulation techniques yielded a 3% improvement in energy yield, which equates to an increase of over 600 MWh or £55,000 per year.